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Ir Remote Code Arduino | Sending Ir Codes

How to Use Infrared Remotes and Receivers on the Arduino - Ultimate Guide to the Arduino #26

Components and supplies

IR receiver (generic)

Arduino UNO

JustBoom IR Remote

Tools and machines

IR Remote Libary

Apps and platforms

Arduino IDE

Project description

Code

Code

c_cpp

Upload the Code and See the Code of Button Pressed in Serial Monitor

Downloadable files

Circuit Diagram

1. Connect the First pin from the left of TSOP1738 (OUT pin) with pin 11 of Arduino. 2. Hook the Middle pin (GND pin) with the GND pin of Arduino. 3. Connect the third and the last pin (VCC pin) with 5V pin of Arduino.

Circuit Diagram

Circuit Diagram

1. Connect the First pin from the left of TSOP1738 (OUT pin) with pin 11 of Arduino. 2. Hook the Middle pin (GND pin) with the GND pin of Arduino. 3. Connect the third and the last pin (VCC pin) with 5V pin of Arduino.

Circuit Diagram

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Table of contents

Intro

Bài 14: Điều khiển LED bằng IR Remote sử dụng Arduino

Trong nội dung bài viết khóa học lập trình Arduino hôm mình mình xin gửi đến các bạn một chủ đề mới (linh kiện mới IR), dùng để điều khiển các thiết bị.

Thông qua bài viết các bạn sẽ nắm được chức năng cấu tạo của IR Receiver trong lập trình Arduino.

Với chủ đề hôm nay mình sẽ dùng ánh sáng hồng ngoại IR để bật tắt LED nhé.

Unknown protocol

If your protocol seems not to be supported by this library, you may try the

IRMP library

.

Sending IR codes

If you have a device at hand which can generate the IR codes you want to work with (aka IR remote),

it is recommended

to receive the codes with the

ReceiveDemo example

, which will tell you on the serial output how to send them.

Protocol=LG Address=0x2 Command=0x3434 Raw-Data=0x23434E 28 bits MSB first
Send with: IrSender.sendLG(0x2, 0x3434, );

You will discover that

the address is a constant

and the commands sometimes are sensibly grouped.
If you are uncertain about the numbers of repeats to use for sending, is a good starting point. If this works, you can check lower values afterwards.

The codes found in the

irdb database

specify a

device

, a

subdevice

and a

function

. Most of the times, device and subdevice can be taken as upper and lower byte of the

address parameter

and function is the

command parameter

for the

new structured functions

with address, command and repeat-count parameters like e.g.

IrSender.sendNEC((device << 8) | subdevice, 0x19, 2)

.
An

exact mapping

can be found in the

IRP definition files for IR protocols

. “D” and “S” denotes device and subdevice and “F” denotes the function.


All sending functions support the sending of repeats

if sensible.
Repeat frames are sent at a fixed period determined by the protocol. e.g. 110 ms from start to start for NEC.
Keep in mind, that

there is no delay after the last sent mark

.
If you handle the sending of repeat frames by your own, you must insert sensible delays before the repeat frames to enable correct decoding.

The old send*Raw() functions for sending like e.g.

IrSender.sendNECRaw(0xE61957A8,2)

are kept for backward compatibility to

(old)

tutorials and unsupported as well as error prone.

How to Use Infrared Remotes and Receivers on the Arduino - Ultimate Guide to the Arduino #26
How to Use Infrared Remotes and Receivers on the Arduino – Ultimate Guide to the Arduino #26

How to convert old MSB first 32 bit IR data codes to new LSB first 32 bit IR data codes

For the new decoders for

NEC, Panasonic, Sony, Samsung and JVC

, the result

IrReceiver.decodedIRData.decodedRawData

is now

LSB-first

, as the definition of these protocols suggests!

To convert one into the other, you must reverse the byte/nibble positions and then reverse all bit positions of each byte/nibble or write it as one binary string and reverse/mirror it.
Example:

0xCB 34 01 02


0x20 10 43 BC

after nibble reverse

0x40 80 2C D3

after bit reverse of each nibble

Nibble reverse map:

 0->0   1->8   2->4   3->C
 4->2   5->A   6->6   7->E
 8->1   9->9   A->5   B->D
 C->3   D->B   E->7   F->F


0xCB340102

is binary

1100 1011 0011 0100 0000 0001 0000 0010

.

0x40802CD3

is binary

0100 0000 1000 0000 0010 1100 1101 0011

.
If you

read the first binary sequence backwards

(right to left), you get the second sequence.
You may use

bitreverseOneByte()

or

bitreverse32Bit()

for this.

Errors with using the 4.x versions for old tutorials

If you suffer from errors with old tutorial code including

IRremote.h

instead of

IRremote.hpp

, just try to rollback to

Version 2.4.0

.
Most likely your code will run and you will not miss the new features…

Staying on 2.x

Consider using the

original 2.4 release form 2017

or the last backwards compatible

2.8 version

for you project.
It may be sufficient and deals flawlessly with 32 bit IR codes.
If this doesn’t fit your case, be assured that 3.x is at least trying to be backwards compatible, so your old examples should still work fine.

Drawbacks

  • Only the following decoders are available:

    NEC


    Denon


    Panasonic


    JVC


    LG


    RC5


    RC6


    Samsung


    Sony
  • The call of

    irrecv.decode(&results)

    uses the old MSB first decoders like in 2.x and sets the 32 bit codes in

    results.value

    .
  • The old functions

    sendNEC()

    and

    sendJVC()

    are renamed to

    sendNECMSB()

    and

    sendJVCMSB()

    .
    Use them to send your

    old MSB-first 32 bit IR data codes

    .
  • No decoding by a (constant) 8/16 bit address and an 8 bit command.

Why *.hpp instead of *.cpp?


Every *.cpp file is compiled separately

by a call of the compiler exclusively for this cpp file. These calls are managed by the IDE / make system.
In the Arduino IDE the calls are executed when you click on Verify or Upload.

And now our problem with Arduino is:

How to set

compile options

for all *.cpp files, especially for libraries used?

IDE’s like

Sloeber

or

PlatformIO

support this by allowing to specify a set of options per project.
They add these options at each compiler call e.g.

-DTRACE

.

But Arduino lacks this feature.
So the

workaround

is not to compile all sources separately, but to concatenate them to one huge source file by including them in your source.
This is done by e.g.

#include "IRremote.hpp"

.

But why not

#include "IRremote.cpp"

?
Try it and you will see tons of errors, because each function of the *.cpp file is now compiled twice,
first by compiling the huge file and second by compiling the *.cpp file separately, like described above.
So using the extension cpp is not longer possible, and one solution is to use hpp as extension, to show that it is an included *.cpp file.
Every other extension e.g. cinclude would do, but hpp seems to be common sense.

Using the new *.hpp files

In order to support

compile options

more easily,
you must use the statement

#include

instead of

#include

in your main program (aka *.ino file with setup() and loop()).

In

all other files

you must use the following, to

prevent

multiple definitions

linker errors

:

#

define

USE_IRREMOTE_HPP_AS_PLAIN_INCLUDE

#

include

IRremote.hpp


Ensure that all macros in your main program are defined before any


#include

.
The following macros will definitely be overridden with default values otherwise:


  • RAW_BUFFER_LENGTH

  • IR_SEND_PIN

  • SEND_PWM_BY_TIMER

Receiving IR codes

Check for a

completly received IR frame

with:

if (IrReceiver.decode()) {}

This also decodes the received data.
After successful decoding, the IR data is contained in the IRData structure, available as

IrReceiver.decodedIRData

.

Decode any IR remote using Arduino | Easy way
Decode any IR remote using Arduino | Easy way

Increase strength of sent output signal


The best way to increase the IR power for free

is to use 2 or 3 IR diodes in series. One diode requires 1.2 volt at 20 mA or 1.5 volt at 100 mA so you can supply up to 3 diodes with a 5 volt output.
To power

2 diodes

with 1.2 V and 20 mA and a 5 V supply, set the resistor to: (5 V – 2.4 V) -> 2.6 V / 20 mA =

130 Ω

.
For

3 diodes

it requires 1.4 V / 20 mA =

70 Ω

.
The actual current might be lower since of

loss at the AVR pin

. E.g. 0.3 V at 20 mA.
If you do not require more current than 20 mA, there is no need to use an external transistor (at least for AVR chips).

On my Arduino Nanos, I always use a 100 Ω series resistor and one IR LED 😀.

CHI TIẾT BÀI VIẾT

Hướng dẫn điều khiển LED với IR Remote Control

1. Mô tả

Sử dụng bộ thu hồng ngoại (IR) để điều khiển 3 đèn LED bằng điều khiển từ xa.

Bật và tắt chúng bằng các nút trên điều khiển từ xa

Thực hành này được chia thành hai phần:

  • Phần 1 sẽ giải mã tín hiệu IR được điều khiển từ xa truyền đi
  • Phần 2 sẽ sử dụng thông tin đó để thực hiện một tác vụ với Arduino điều khiển 3 đèn LED

2. Chuẩn bị

  • Arduino UNO – read Best Arduino Starter Kits
  • 1x Breadboard
  • 1x Remote control
  • 1x IR receiver ( I’ll be using IR1838)
  • 3x LEDs (1x Red, 1x Yellow, 1x Green)
  • 4x 220 Ohm resistors
  • Jumper cables

Infrared (IR) Receiver

3. Hướng dẫn thực hiện

Sơ đồ giải mã giải mã tín hiệu IR

Cài đặt thư viện IRremote https://github.com/z3t0/Arduino-IRremote/archive/master.zip

Giải nén thư mục .zip và bạn sẽ nhận được thư mục IRremote-master

Đổi tên thư mục của bạn từ IRremote-master thành IRremote

Di chuyển thư mục IRremote vào thư mục thư viện cài đặt Arduino IDE của bạn

Cuối cùng, mở lại Arduino IDE của bạn

Chọn 6 nút cho các tác vụ sau:

  • LED1 – ON
  • LED1 – OFF
  • LED2 – ON
  • LED2 – OFF
  • LED3 – ON
  • LED3 – OFF

Nhấn nút số 1 ==> Bạn sẽ thấy mã trên màn hình

Nhấn cùng một nút nhiều lần để đảm bảo bạn có đúng mã cho nút đó (nếu thấy FFFFFFFF thì bỏ qua)

Viết ra mã được liên kết với mỗi nút, vì bạn sẽ cần thông tin đó sau này.

Bây giờ, lấy các mã bạn đã chụp ở bước trước, chuyển đổi mã từ thập lục phân sang thập phân, sử dụng trang web sau:

https://www.binaryhexconverter.com/hex-to-decimal-converter

Sơ đồ lắp mạch cuối cùng

3. Code nạp vào Arduino

4. Hoàn thành => Đèn LED với IR Remote Control

Arduino Tutorial 31- How to Use the Infrared (IR) Remote
Arduino Tutorial 31- How to Use the Infrared (IR) Remote

New features with version 4.x

  • New universal

    Pulse Distance / Pulse Width decoder

    added, which covers many previous unknown protocols.
  • Printout of code how to send received command by

    IrReceiver.printIRSendUsage(&Serial)

    .
  • RawData type is now 64 bit for 32 bit platforms and therefore

    decodedIRData.decodedRawData

    can contain complete frame information for more protocols than with 32 bit as before.
  • Callback after receiving a command – It calls your code as soon as a message was received.
  • Improved handling of

    PULSE_DISTANCE

    +

    PULSE_WIDTH

    protocols.
  • New FAST protocol.
Converting your 3.x program to the 4.x version
  • You must replace

    #define DECODE_DISTANCE

    by

    #define DECODE_DISTANCE_WIDTH

    (only if you explicitly enabled this decoder).
  • The parameter

    bool hasStopBit

    is not longer required and removed e.g. for function

    sendPulseDistanceWidth()

    .

Does not work/compile with another library


Another library is only working/compiling

if you deactivate the line

IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);

.
This is often due to

timer resource conflicts

with the other library. Please see

below

.

How To Use Infrared Remote using Arduino - New Method
How To Use Infrared Remote using Arduino – New Method

Read data from the IR remote controller

Here is the code to print the corresponding data for each button you press.

#include

#define IR_RECEIVE_PIN 8 void setup() { Serial.begin(9600); IrReceiver.begin(IR_RECEIVE_PIN); } void loop() { if (IrReceiver.decode()) { IrReceiver.resume(); Serial.println(IrReceiver.decodedIRData.command); } }

Let’s break this down line by line.

#include

#define IR_RECEIVE_PIN 8

First you need to include the library you’ve just installed. We also use a define for the data pin of the IR receiver.

void setup() { Serial.begin(9600); IrReceiver.begin(IR_RECEIVE_PIN); }

In the void setup() function, we initialize the Serial communication and the IR receiver. For the IR receiver, you use the begin() function with one argument: the number of the data pin for the IR receiver.

void loop() { if (IrReceiver.decode()) { IrReceiver.resume(); Serial.println(IrReceiver.decodedIRData.command); } }

In the void loop() function, we continuously check if some new data is available with IrReceiver.decode(). If yes, we immediately call IrReceiver.resume() so that the sensor will continue to read data – if you don’t do this you will get weird errors.

And to get access to the data, we need to use IrReceiver.decodedIRData.command.

If you run this program on your Arduino, and open the Serial Monitor, you’ll see something like this:

12 24 94 28

For each button you press, you’ll get a number.

Send pin

Any pin can be choosen as send pin, because the PWM signal is generated by default with software bit banging, since

SEND_PWM_BY_TIMER

is not active.
If

IR_SEND_PIN

is specified (as c macro), it reduces program size and improves send timing for AVR. If you want to use a variable to specify send pin e.g. with

setSendPin(uint8_t aSendPinNumber)

, you must disable this

IR_SEND_PIN

macro. Then you can change send pin at any time before sending an IR frame. See also

Compile options / macros for this library

.

List of public IR code databases


http://www.harctoolbox.org/IR-resources.html

Arduino IR Remote Control LED | Arduino IR Receiver
Arduino IR Remote Control LED | Arduino IR Receiver

Print Keys to an LCD

Instead of printing the key values to the serial monitor, you can also display the information on an LCD. Check out our article on setting up and programming an LCD on the Arduino for more information on programming the LCD, but the basic setup looks like this:

The resistor sets the LCD’s backlight brightness. It can be anything from 200 ohms to about 2K ohms. The potentiometer sets the character contrast. I normally use a 10K ohm potentiometer for this one.

Once everything is connected, upload this code to the Arduino:


#include

#include const int RECV_PIN = 7; LiquidCrystal lcd(12, 11, 5, 4, 3, 2); IRrecv irrecv(RECV_PIN); decode_results results; unsigned long key_value = 0; void setup(){ Serial.begin(9600); irrecv.enableIRIn(); irrecv.blink13(true); lcd.begin(16, 2); } void loop(){ if (irrecv.decode(&results)){ if (results.value == 0XFFFFFFFF) results.value = key_value; lcd.setCursor(0, 0); lcd.clear(); switch(results.value){ case 0xFFA25D: lcd.print("CH-"); break; case 0xFF629D: lcd.print("CH"); break; case 0xFFE21D: lcd.print("CH+"); break; case 0xFF22DD: lcd.print("|<<"); break; case 0xFF02FD: lcd.print(">>|"); break ; case 0xFFC23D: lcd.print(">|"); break ; case 0xFFE01F: lcd.print("-"); break ; case 0xFFA857: lcd.print("+"); break ; case 0xFF906F: lcd.print("EQ"); break ; case 0xFF6897: lcd.print("0"); break ; case 0xFF9867: lcd.print("100+"); break ; case 0xFFB04F: lcd.print("200+"); break ; case 0xFF30CF: lcd.print("1"); break ; case 0xFF18E7: lcd.print("2"); break ; case 0xFF7A85: lcd.print("3"); break ; case 0xFF10EF: lcd.print("4"); break ; case 0xFF38C7: lcd.print("5"); break ; case 0xFF5AA5: lcd.print("6"); break ; case 0xFF42BD: lcd.print("7"); break ; case 0xFF4AB5: lcd.print("8"); break ; case 0xFF52AD: lcd.print("9"); break ; } key_value = results.value; irrecv.resume(); } }

Again, if the hex codes don’t match the codes output by your remote, just replace them for each character where it says

case 0xXXXXXXXX;

.

How to deal with protocols not supported by IRremote

If you do not know which protocol your IR transmitter uses, you have several choices.

Examples for this library

The examples are available at File > Examples > Examples from Custom Libraries / IRremote.
In order to fit the examples to the 8K flash of ATtiny85 and ATtiny88, the

Arduino library ATtinySerialOut

is required for this CPU’s.

SimpleReceiver + SimpleSender

The


SimpleReceiver


and


SimpleSender


examples are a good starting point.
A simple example can be tested online with

WOKWI

.

TinyReceiver + TinySender

If

code size

or

timer usage

matters, look at these examples.
The


TinyReceiver


example uses the

TinyIRReceiver

library
which can

only receive NEC, Extended NEC, ONKYO and FAST protocols, but does not require any timer

.
They use pin change interrupt for on the fly decoding, which is the reason for the restricted protocol choice.
TinyReceiver can be tested online with

WOKWI

.

The


TinySender


example uses the

TinyIRSender

library which can

only send NEC, ONKYO and FAST protocols

.
It sends NEC protocol codes in standard format with 8 bit address and 8 bit command as in SimpleSender example.
Saves 780 bytes program memory and 26 bytes RAM compared to SimpleSender, which does the same, but uses the IRRemote library (and is therefore much more flexible).

SmallReceiver

If the protocol is not NEC and code size matters, look at this

example

.

ReceiveDemo + AllProtocolsOnLCD


ReceiveDemo

receives all protocols and

generates a beep with the Arduino tone() function

on each packet received.
Long press of one IR button (receiving of multiple repeats for one command) is detected.

AllProtocolsOnLCD

additionally

displays the short result on a 1602 LCD

. The LCD can be connected parallel or serial (I2C).
By connecting debug pin to ground, you can force printing of the raw values for each frame. The pin number of the debug pin is printed during setup, because it depends on board and LCD connection type.
This example also serves as an

example how to use IRremote and tone() together

.

ReceiveDump

Receives all protocols and dumps the received signal in different flavors including Pronto format. Since the printing takes much time, repeat signals may be skipped or interpreted as UNKNOWN.

SendDemo

Sends all available protocols at least once.

SendAndReceive

Demonstrates

receiving while sending

.

ReceiveAndSend

Record and

play back last received IR signal

at button press. IR frames of known protocols are sent by the approriate protocol encoder.

UNKNOWN

protocol frames are stored as raw data and sent with

sendRaw()

.

ReceiveAndSendDistanceWidth

Try to decode each IR frame with the universal

DistanceWidth decoder

, store the data and send it on button press with

sendPulseDistanceWidthFromArray()

.
Storing data for distance width protocol requires 17 bytes.
The ReceiveAndSend example requires 16 bytes for known protocol data and 37 bytes for raw data of e.g.NEC protocol.

ReceiveOneAndSendMultiple

Serves as a IR

remote macro expander

. Receives Samsung32 protocol and on receiving a specified input frame, it sends multiple Samsung32 frames with appropriate delays in between.
This serves as a

Netflix-key emulation

for my old Samsung H5273 TV.

IRDispatcherDemo

Framework for

calling different functions of your program

for different IR codes.

IRrelay


Control a relay

(connected to an output pin) with your remote.

IRremoteExtensionTest


Example

for a user defined class, which itself uses the IRrecv class from IRremote.

SendLGAirConditionerDemo


Example

for sending LG air conditioner IR codes controlled by Serial input.
By just using the function

bool Aircondition_LG::sendCommandAndParameter(char aCommand, int aParameter)

you can control the air conditioner by any other command source.
The file acLG.h contains the command documentation of the LG air conditioner IR protocol. Based on reverse engineering of the LG AKB73315611 remote.

IReceiverTimingAnalysis can be tested online with

WOKWI

Click on the receiver while simulation is running to specify individual IR codes.

ReceiverTimingAnalysis

This

example

analyzes the signal delivered by your IR receiver module.
Values can be used to determine the stability of the received signal as well as a hint for determining the protocol.
It also computes the

MARK_EXCESS_MICROS

value, which is the extension of the mark (pulse) duration introduced by the IR receiver module.
It can be tested online with

WOKWI

.
Click on the receiver while simulation is running to specify individual NEC IR codes.

UnitTest

ReceiveDemo + SendDemo in one program. Demonstrates

receiving while sending

.
Here you see the delay of the receiver output (blue) from the IR diode input (yellow).

WOKWI online examples

Issues and discussions

  • Do not open an issue without first testing some of the examples!
  • If you have a problem, please post the MCVE (Minimal Complete Verifiable Example) showing this problem. My experience is, that most of the times you will find the problem while creating this MCVE 😄.

  • Use code blocks

    ;

    it helps us help you when we can read your code!

Compile options / macros for this library

To customize the library to different requirements, there are some compile options / macros available.
These macros must be defined in your program

before

the line

#include

to take effect.
Modify them by enabling / disabling them, or change the values if applicable.

Name
Default value
Description

RAW_BUFFER_LENGTH

100
Buffer size of raw input buffer. Must be even! 100 is sufficient for regular protocols of up to 48 bits, but for most air conditioner protocols a value of up to 750 is required. Use the ReceiveDump example to find smallest value for your requirements.

EXCLUDE_UNIVERSAL_PROTOCOLS

disabled
Excludes the universal decoder for pulse distance protocols and decodeHash (special decoder for all protocols) from

decode()

. Saves up to 1000 bytes program memory.

DECODE_

all
Selection of individual protocol(s) to be decoded. You can specify multiple protocols. See

here


DECODE_STRICT_CHECKS

disabled
Check for additional required characteristics of protocol timing like length of mark for a constant mark protocol, where space length determines the bit value. Requires up to 194 additional bytes of program memory.

IR_REMOTE_DISABLE_RECEIVE_COMPLETE_CALLBACK

disabled
Saves up to 60 bytes of program memory and 2 bytes RAM.

MARK_EXCESS_MICROS

20
MARK_EXCESS_MICROS is subtracted from all marks and added to all spaces before decoding, to compensate for the signal forming of different IR receiver modules.

RECORD_GAP_MICROS

5000
Minimum gap between IR transmissions, to detect the end of a protocol.Must be greater than any space of a protocol e.g. the NEC header space of 4500 µs.Must be smaller than any gap between a command and a repeat; e.g. the retransmission gap for Sony is around 24 ms.Keep in mind, that this is the delay between the end of the received command and the start of decoding.

IR_INPUT_IS_ACTIVE_HIGH

disabled
Enable it if you use a RF receiver, which has an active HIGH output signal.

IR_SEND_PIN

disabled
If specified, it reduces program size and improves send timing for AVR. If you want to use a variable to specify send pin e.g. with

setSendPin(uint8_t aSendPinNumber)

, you must not use / disable this macro in your source.

SEND_PWM_BY_TIMER

disabled
Disables carrier PWM generation in software and use hardware PWM (by timer). Has the advantage of more exact PWM generation, especially the duty cycle (which is not very relevant for most IR receiver circuits), and the disadvantage of using a hardware timer, which in turn is not available for other libraries and to fix the send pin (but not the receive pin) at the

dedicated timer output pin(s)

. Is enabled for ESP32 and RP2040 in all examples, since they support PWM gereration for each pin without using a shared resource (timer).

USE_NO_SEND_PWM

disabled
Uses no carrier PWM, just simulate an

active low

receiver signal. Used for transferring signal by cable instead of IR. Overrides

SEND_PWM_BY_TIMER

definition.

IR_SEND_DUTY_CYCLE_PERCENT

30
Duty cycle of IR send signal.

USE_OPEN_DRAIN_OUTPUT_FOR_SEND_PIN

disabled
Uses or simulates open drain output mode at send pin.

Attention, active state of open drain is LOW

, so connect the send LED between positive supply and send pin!

DISABLE_CODE_FOR_RECEIVER

disabled
Saves up to 450 bytes program memory and 269 bytes RAM if receiving functionality is not required.

EXCLUDE_EXOTIC_PROTOCOLS

disabled
Excludes BANG_OLUFSEN, BOSEWAVE, WHYNTER, FAST and LEGO_PF from

decode()

and from sending with

IrSender.write()

. Saves up to 650 bytes program memory.

FEEDBACK_LED_IS_ACTIVE_LOW

disabled
Required on some boards (like my BluePill and my ESP8266 board), where the feedback LED is active low.

NO_LED_FEEDBACK_CODE

disabled
Disables the LED feedback code for send and receive. Saves around 100 bytes program memory for receiving, around 500 bytes for sending and halving the receiver ISR (Interrupt Service Routine) processing time.

MICROS_PER_TICK

50
Resolution of the raw input buffer data. Corresponds to 2 pulses of each 26.3 µs at 38 kHz.

TOLERANCE_FOR_DECODERS_MARK_OR_SPACE_MATCHING

25
Relative tolerance (in percent) for matchTicks(), matchMark() and matchSpace() functions used for protocol decoding.

DEBUG

disabled
Enables lots of lovely debug output.

IR_USE_AVR_TIMER*

Selection of timer to be used for generating IR receiving sample interval.

These next macros for

TinyIRReceiver

must be defined in your program before the line

#include

to take effect.

Name
Default value
Description

IR_RECEIVE_PIN

2
The pin number for TinyIRReceiver IR input, which gets compiled in.

IR_FEEDBACK_LED_PIN


LED_BUILTIN

The pin number for TinyIRReceiver feedback LED, which gets compiled in.

NO_LED_FEEDBACK_CODE

disabled
Disables the feedback LED function. Saves 14 bytes program memory.

DISABLE_PARITY_CHECKS

disabled
Disables the addres and command parity checks. Saves 48 bytes program memory.

USE_EXTENDED_NEC_PROTOCOL

disabled
Like NEC, but take the 16 bit address as one 16 bit value and not as 8 bit normal and 8 bit inverted value.

USE_ONKYO_PROTOCOL

disabled
Like NEC, but take the 16 bit address and command each as one 16 bit value and not as 8 bit normal and 8 bit inverted value.

USE_FAST_PROTOCOL

disabled
Use FAST protocol (no address and 16 bit data, interpreted as 8 bit command and 8 bit inverted command) instead of NEC.

ENABLE_NEC2_REPEATS

disabled
Instead of sending / receiving the NEC special repeat code, send / receive the original frame for repeat.

USE_CALLBACK_FOR_TINY_RECEIVER

disabled
Call the fixed function

void handleReceivedTinyIRData()

each time a frame or repeat is received.

The next macro for

IRCommandDispatcher

must be defined in your program before the line

#include

to take effect.
|

USE_TINY_IR_RECEIVER

| disabled | Use

TinyReceiver

for receiving IR codes. |
|

IR_COMMAND_HAS_MORE_THAN_8_BIT

| disabled | Enables mapping and dispatching of IR commands consisting of more than 8 bits. Saves up to 160 bytes program memory and 4 bytes RAM + 1 byte RAM per mapping entry. |
|

BUZZER_PIN

| | If

USE_TINY_IR_RECEIVER

is enabled, the pin to be used for the optional 50 ms buzzer feedback before executing a command. Other IR libraries than Tiny are not compatible with tone() command. |

Changing include (*.h) files with Arduino IDE

First, use Sketch > Show Sketch Folder (Ctrl+K).
If you have not yet saved the example as your own sketch, then you are instantly in the right library folder.
Otherwise you have to navigate to the parallel

libraries

folder and select the library you want to access.
In both cases the library source and include files are located in the libraries

src

directory.
The modification must be renewed for each new library version!

Modifying compile options / macros with PlatformIO

If you are using PlatformIO, you can define the macros in the

platformio.ini

file with

build_flags = -D MACRO_NAME

or

build_flags = -D MACRO_NAME=macroValue

.

Modifying compile options / macros with Sloeber IDE

If you are using

Sloeber

as your IDE, you can easily define global symbols with Properties > Arduino > CompileOptions.

Supported Boards


Issues and discussions with the content “Is it possible to use this library with the ATTinyXYZ? / board XYZ” without any reasonable explanations will be immediately closed without further notice.

Digispark boards are only tested with

ATTinyCore

using

New Style

pin mapping for the Digispark Pro board.
ATtiny boards are only tested with

ATTinyCore

or

megaTinyCore

.

  • Arduino Uno / Mega / Leonardo / Duemilanove / Diecimila / LilyPad / Mini / Fio / Nano etc.
  • Arduino Uno R4, but not yet tested, because of lack of a R4 board.

    Sending does not work

    on the

    arduino:renesas_uno:unor4wifi

    .
  • Teensy 1.0 / 1.0++ / 2.0 / 2++ / 3.0 / 3.1 / 3.2 / Teensy-LC – but

    limited support

    ; Credits: PaulStoffregen (Teensy Team)
  • Sanguino
  • ATmega8, 48, 88, 168, 328
  • ATmega8535, 16, 32, 164, 324, 644, 1284,
  • ATmega64, 128
  • ATmega4809 (Nano every)
  • ATtiny3217 (Tiny Core 32 Dev Board)
  • ATtiny84, 85, 167 (Digispark + Digispark Pro)
  • SAMD21 (Zero, MKR*,

    but not SAMD51 and not DUE, the latter is SAM architecture

    )
  • ESP8266
  • ESP32 (ESP32-C3 since board package 2.0.2 from Espressif)

    not for ESP32 core version > 3.0.0
  • Sparkfun Pro Micro
  • Nano Every, Uno WiFi Rev2, nRF5 BBC MicroBit, Nano33_BLE
  • BluePill with STM32
  • RP2040 based boards (Raspberry Pi Pico, Nano RP2040 Connect etc.)

For ESP8266/ESP32,

this library

supports an

impressive set of protocols and a lot of air conditioners

We are open to suggestions for adding support to new boards, however we highly recommend you contact your supplier first and ask them to provide support from their side.
If you can provide

examples of using a periodic timer for interrupts

for the new board, and the board name for selection in the Arduino IDE, then you have way better chances to get your board supported by IRremote.

Timer and pin usage

The

receiver sample interval of 50 µs is generated by a timer

. On many boards this must be a hardware timer. On some boards where a software timer is available, the software timer is used.

Every pin can be used for receiving.
If software PWM is selected, which is default, every pin can also be used for sending. Sending with software PWM does not require a timer!

The TinyReceiver example uses the

TinyReceiver

library, which can

only receive NEC codes, but does not require any timer

and runs even on a 1 MHz ATtiny85.

The code for the timer and the

timer selection

is located in

private/IRTimer.hpp

. The selected timer can be adjusted here.


Be aware that the hardware timer used for receiving should not be used for analogWrite()!

.

No timer required for sending

The

send PWM signal

is by default generated by software.

Therefore every pin can be used for sending

.
The PWM pulse length is guaranteed to be constant by using

delayMicroseconds()

.
Take care not to generate interrupts during sending with software generated PWM, otherwise you will get jitter in the generated PWM.
E.g. wait for a former

Serial.print()

statement to be finished by

Serial.flush()

.
Since the Arduino

micros()

function has a resolution of 4 µs at 16 MHz, we always see a small jitter in the signal, which seems to be OK for the receivers.

Software generated PWM showing small jitter because of the limited resolution of 4 µs of the Arduino core

micros()

function for an ATmega328
Detail (ATmega328 generated) showing 30% duty cycle

LÀM CÁCH NÀO ĐỂ GIẢI MÃ IR REMOTE TRÊN ARDUINO | Long Automation
LÀM CÁCH NÀO ĐỂ GIẢI MÃ IR REMOTE TRÊN ARDUINO | Long Automation

Does not work/compile with another library


Another library is only working/compiling

if you deactivate the line

IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);

.
This is often due to

timer resource conflicts

with the other library. Please see

below

.

Bang & Olufsen protocol

The Bang & Olufsen protocol decoder is not enabled by default, i.e if no protocol is enabled explicitly by #define

DECODE_

. It must always be enabled explicitly by

#define DECODE_BEO

.
This is because it has an

IR transmit frequency of 455 kHz

and therefore requires a different receiver hardware (TSOP7000).
And because

generating a 455 kHz PWM signal is currently only implemented for

SEND_PWM_BY_TIMER


, sending only works if

SEND_PWM_BY_TIMER

or

USE_NO_SEND_PWM

is defined.
For more info, see

ir_BangOlufsen.hpp

.

Handling unknown Protocols

5-min Tutorials: Arduino IR Remote & Receiver
5-min Tutorials: Arduino IR Remote & Receiver

Arduino Code

  • Arduino code for DIYables 17-key IR remote controller
  • Arduino code for DIYables 21-key IR remote controller
Quick Steps
  • Navigate to the Libraries icon on the left bar of the Arduino IDE.
  • Search “DIYables_IRcontroller”, then find the DIYables_IRcontroller library by DIYables
  • Click Install button to install DIYables_IRcontroller library.
  • You will be asked for installing the library dependency as below image:
  • Click Install all button to install the dependency
  • Copy the above code and open with Arduino IDE
  • Click Upload button on Arduino IDE to upload code to Arduino
  • Press keys on the remote controller one by one
  • See the result on Serial Monitor.
  • The below is the result when you press keys on 21-key IR controller one by one:

Now you can modify the code to control LED, fan, pump, actuator… via IR remote controllers.

Multiple IR receivers

IRreceiver consists of one timer triggered function reading the digital IR signal value from one pin every 50 µs.
So

multiple IR receivers

can only be used by connecting the output pins of several IR receivers together.
The IR receivers use an NPN transistor as output device with just a 30k resistor to VCC.
This is almost “open collector” and allows connecting of several output pins to one Arduino input pin.
But keep in mind, that any weak / disturbed signal from one of the receivers will in turn also disturb a good signal from another one.

Create Your Own Universal Remote Controller! | DIY ATtiny85 IR Remote
Create Your Own Universal Remote Controller! | DIY ATtiny85 IR Remote

Bang & Olufsen protocol

The Bang & Olufsen protocol decoder is not enabled by default, i.e if no protocol is enabled explicitly by #define

DECODE_

. It must always be enabled explicitly by

#define DECODE_BEO

.
This is because it has an

IR transmit frequency of 455 kHz

and therefore requires a different receiver hardware (TSOP7000).
And because

generating a 455 kHz PWM signal is currently only implemented for

SEND_PWM_BY_TIMER


, sending only works if

SEND_PWM_BY_TIMER

or

USE_NO_SEND_PWM

is defined.
For more info, see

ir_BangOlufsen.hpp

.

Handling unknown Protocols

Incompatibilities to other libraries and Arduino commands like tone() and analogWrite()

If you use a library which requires the same timer as IRremote, you have a problem, since

the timer resource cannot be shared simultaneously

by both libraries.

Change timer

The best approach is to change the timer used for IRremote, which can be accomplished by specifying the timer before

#include

.
The timer specifications available for your board can be found in

private/IRTimer.hpp

.

//

Arduino Mega

#elif

defined

(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) #

if

!defined(IR_USE_AVR_TIMER1) && !defined(IR_USE_AVR_TIMER2) && !defined(IR_USE_AVR_TIMER3) && !defined(IR_USE_AVR_TIMER4) && !defined(IR_USE_AVR_TIMER5)

//

#define IR_USE_AVR_TIMER1 // send pin = pin 11

#define IR_USE_AVR_TIMER2

//

send pin = pin 9

//

#define IR_USE_AVR_TIMER3 // send pin = pin 5

//

#define IR_USE_AVR_TIMER4 // send pin = pin 6

//

#define IR_USE_AVR_TIMER5 // send pin = pin 46

# endif

Here you see the Arduino Mega board and the available specifications are

IR_USE_AVR_TIMER[1,2,3,4,5]

.
You

just have to include a line

e.g.

#define IR_USE_AVR_TIMER3

before

#include

to enable timer 3.

But be aware that the new timer in turn might be incompatible with other libraries or commands.
For other boards/platforms you must look for the appropriate section guarded by e.g.

#elif defined(ESP32)

.

Stop and start timer

Another approach can be to share the timer

sequentially

if their functionality is used only for a short period of time like for the

Arduino tone() command

.
An example can be seen

here

, where the timer settings for IR receive are restored after the tone has stopped.
For this we must call

IrReceiver.start()

or better

IrReceiver.start(microsecondsOfToneDuration)

.
This only works since each call to

tone()

completely initializes the timer 2 used by the

tone()

command.

ARDUINO: IR REMOTE CONTROL OF LEDS
ARDUINO: IR REMOTE CONTROL OF LEDS

Hardware-PWM signal generation for sending

If you define

SEND_PWM_BY_TIMER

, the send PWM signal is forced to be generated by a hardware timer on most platforms.
By default, the same timer as for the receiver is used.
Since each hardware timer has its dedicated output pin(s), you must change timer or timer sub-specifications to change PWM output pin. See

private/IRTimer.hpp


Exeptions

are currently

ESP32, ARDUINO_ARCH_RP2040, PARTICLE and ARDUINO_ARCH_MBED

, where

PWM generation does not require a timer

.

Why do we use 30% duty cycle for sending

We

do it

according to the statement in the

Vishay datasheet

:

  • Carrier duty cycle 50 %, peak current of emitter IF = 200 mA, the resulting transmission distance is 25 m.
  • Carrier duty cycle 10 %, peak current of emitter IF = 800 mA, the resulting transmission distance is 29 m. – Factor 1.16
    The reason is, that it is not the pure energy of the fundamental which is responsible for the receiver to detect a signal.
    Due to automatic gain control and other bias effects, high intensity of the 38 kHz pulse counts more than medium intensity (e.g. 50% duty cycle) at the same total energy.

How we decode signals

The IR signal is sampled at a

50 µs interval

. For a constant 525 µs pulse or pause we therefore get 10 or 11 samples, each with 50% probability.
And believe me, if you send a 525 µs signal, your receiver will output something between around 400 and 700 µs!
Therefore

we decode by default with a +/- 25% margin

using the formulas

here

.
E.g. for the NEC protocol with its 560 µs unit length, we have TICKS_LOW = 8.358 and TICKS_HIGH = 15.0. This means, we accept any value between 8 ticks / 400 µs and 15 ticks / 750 µs (inclusive) as a mark or as a zero space. For a one space we have TICKS_LOW = 25.07 and TICKS_HIGH = 45.0.
And since the receivers generated marks are longer or shorter than the spaces,
we have introduced the


MARK_EXCESS_MICROS


macro
to compensate for this receiver (and signal strength as well as ambient light dependent 😞 ) specific deviation.
Welcome to the world of

real world signal processing

.

NEC encoding diagrams

Created with sigrok PulseView with IR_NEC decoder by DjordjeMandic.
8 bit address NEC code

16 bit address NEC code

Quick comparison of 5 Arduino IR receiving libraries


This is a short comparison and may not be complete or correct.

I created this comparison matrix for

myself

in order to choose a small IR lib for my project and to have a quick overview, when to choose which library.
It is dated from

24.06.2022

and updated 10/2023. If you have complains about the data or request for extensions, please send a PM or open a discussion.


Here

you find an

ESP8266/ESP32

version of IRremote with an


impressive list of supported protocols


.

Subject

IRMP


IRLremote


IRLib2


mostly unmaintained


IRremote


TinyIR


IRsmallDecoder

Number of protocols

50

Nec + Panasonic + Hash *
12 + Hash *
17 + PulseDistance + Hash *
NEC + FAST
NEC + RC5 + Sony + Samsung

Timing method receive
Timer2 or interrupt for pin 2 or 3

Interrupt

Timer2 or interrupt for pin 2 or 3
Timer2

Interrupt


Interrupt

Timing method send
PWM and timing with Timer2 interrupts
Timer2 interrupts
Timer2 and blocking wait
PWM with Timer2 and/or blocking wait with delayMicroseconds()
blocking wait with delayMicroseconds()
%

Send pins
All
All
All ?
Timer dependent
All
%

Decode method
OnTheFly
OnTheFly
RAM
RAM
OnTheFly
OnTheFly

Encode method
OnTheFly
OnTheFly
OnTheFly
OnTheFly or RAM
OnTheFly
%

Callback support
x
%
%
x
x
%

Repeat handling
Receive + Send (partially)
%
?
Receive + Send
Receive + Send
Receive

LED feedback
x
%
x
x
Receive
%

FLASH usage (simple NEC example with 5 prints)
1820(4300 for 15 main / 8000 for all 40 protocols)(+200 for callback)(+80 for interrupt at pin 2+3)
1270(1400 for pin 2+3)
4830
1770

900

?1100?

RAM usage
52(73 / 100 for 15 (main) / 40 protocols)
62
334
227

19

29

Supported platforms

avr, megaavr, attiny, Digispark (Pro), esp8266, ESP32, STM32, SAMD 21, Apollo3(plus arm and pic for non Arduino IDE)

avr, esp8266
avr, SAMD 21, SAMD 51
avr, attiny,

esp8266

, esp32, SAM, SAMD

All platforms with attachInterrupt()


All platforms with attachInterrupt()

Last library update
5/2023
4/2018
11/2022
9/2023
5/2023
2/2022

Remarks
Decodes 40 protocols concurrently.39 Protocols to send.Work in progress.
Only one protocol at a time.
Consists of 5 libraries. *Project containing bugs – 63 issues, 10 pull requests.
Universal decoder and encoder.Supports

Pronto

codes and sending of raw timing values.
Requires no timer.
Requires no timer.

* The Hash protocol gives you a hash as code, which may be sufficient to distinguish your keys on the remote, but may not work with some protocols like Mitsubishi

Useful links

License

Up to the version 2.7.0, the License is GPLv2.
From the version 2.8.0, the license is the MIT license.

Copyright

Initially coded 2009 Ken Shirriff

http://www.righto.com

Copyright (c) 2016-2017 Rafi Khan
Copyright (c) 2020-2023

Armin Joachimsmeyer




Overview

Supported IR Protocols


NEC / Onkyo / Apple


Denon / Sharp


Panasonic / Kaseikyo


JVC


LG


RC5


RC6


Samsung


Sony


Universal Pulse Distance


Universal Pulse Width


Hash


Pronto


BoseWave


Bang & Olufsen


Lego


FAST


Whynter


MagiQuest

Protocols can be switched off and on by defining macros before the line

#include

like

here

:

#

define

DECODE_NEC

//

#define DECODE_DENON

#include

Features

  • Lots of tutorials and examples.
  • Actively maintained.
  • Allows receiving and sending of

    raw timing data

    .
Home Automation using Arduino Bluetooth IR Remote control relay with EEPROM | Arduino Projects 2022
Home Automation using Arduino Bluetooth IR Remote control relay with EEPROM | Arduino Projects 2022

Using the IR Remote to Control Things

Now I’ll show you a simple demonstration of how you can use the IR remote to control the Arduino’s output pins. In this example, we will light up an LED when a particular button is pressed. You can easily modify the code to do things like control servo motors, or activate relays with any button press from the remote.

The example circuit has the IR receiver connected to the Arduino, with a red LED connected to pin 10 and a green LED connected to pin 11:

The code below will write digital pin 10 HIGH for 2 seconds when the “5” button is pressed, and write digital pin 11 HIGH for 2 seconds when the “2” button is pressed:


#include

const int RECV_PIN = 7; IRrecv irrecv(RECV_PIN); decode_results results; const int redPin = 10; const int greenPin = 11; void setup(){ irrecv.enableIRIn(); irrecv.blink13(true); pinMode(redPin, OUTPUT); pinMode(greenPin, OUTPUT); } void loop(){ if (irrecv.decode(&results)){ switch(results.value){ case 0xFF38C7: //Keypad button "5" digitalWrite(redPin, HIGH); delay(2000); digitalWrite(redPin, LOW); } switch(results.value){ case 0xFF18E7: //Keypad button "2" digitalWrite(greenPin, HIGH); delay(2000); digitalWrite(greenPin, LOW); } irrecv.resume(); } }

So far we have covered the properties of infrared radiation and how communication happens between the transmitter and receiver. We saw how to identify the IR key codes for a given remote control. We learned how to display key presses on serial monitor and on an LCD screen. Finally I showed you how to control the Arduino’s output with the remote. Have fun playing with this and be sure to let us know in the comments if you have any questions or trouble setting this up!

In this tutorial I will show you how to setup and use an IR (InfraRed) remote controller with Arduino.

You will learn how to map each button of the controller to a specific action, so you can make your Arduino programs more dynamic.

After reading this post you will be able to fully integrate any IR remote controller to any of your Arduino projects.

Table of Contents

Increase strength of sent output signal


The best way to increase the IR power for free

is to use 2 or 3 IR diodes in series. One diode requires 1.2 volt at 20 mA or 1.5 volt at 100 mA so you can supply up to 3 diodes with a 5 volt output.
To power

2 diodes

with 1.2 V and 20 mA and a 5 V supply, set the resistor to: (5 V – 2.4 V) -> 2.6 V / 20 mA =

130 Ω

.
For

3 diodes

it requires 1.4 V / 20 mA =

70 Ω

.
The actual current might be lower since of

loss at the AVR pin

. E.g. 0.3 V at 20 mA.
If you do not require more current than 20 mA, there is no need to use an external transistor (at least for AVR chips).

On my Arduino Nanos, I always use a 100 Ω series resistor and one IR LED 😀.

Using 2 Pin IF Receivers/Emitters | Arduino Tutorial
Using 2 Pin IF Receivers/Emitters | Arduino Tutorial

Problems with Neopixels, FastLed etc.

IRremote will not work right when you use

Neopixels

(aka WS2811/WS2812/WS2812B) or other libraries blocking interrupts for a longer time (> 50 µs).
Whether you use the Adafruit Neopixel lib, or FastLED, interrupts get disabled on many lower end CPUs like the basic Arduinos for longer than 50 µs.
In turn, this stops the IR interrupt handler from running when it needs to. See also this

video

.

One

workaround

is to wait for the IR receiver to be idle before you send the Neopixel data with

if (IrReceiver.isIdle()) { strip.show();}

.
This

prevents at least breaking a running IR transmission

and -depending of the update rate of the Neopixel- may work quite well.
There are some other solutions to this on more powerful processors,

see this page from Marc MERLIN

Sơ đồ nguyên lý

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New features with version 4.x

  • New universal

    Pulse Distance / Pulse Width decoder

    added, which covers many previous unknown protocols.
  • Printout of code how to send received command by

    IrReceiver.printIRSendUsage(&Serial)

    .
  • RawData type is now 64 bit for 32 bit platforms and therefore

    decodedIRData.decodedRawData

    can contain complete frame information for more protocols than with 32 bit as before.
  • Callback after receiving a command – It calls your code as soon as a message was received.
  • Improved handling of

    PULSE_DISTANCE

    +

    PULSE_WIDTH

    protocols.
  • New FAST protocol.
Converting your 3.x program to the 4.x version
  • You must replace

    #define DECODE_DISTANCE

    by

    #define DECODE_DISTANCE_WIDTH

    (only if you explicitly enabled this decoder).
  • The parameter

    bool hasStopBit

    is not longer required and removed e.g. for function

    sendPulseDistanceWidth()

    .

Send pin

Any pin can be choosen as send pin, because the PWM signal is generated by default with software bit banging, since

SEND_PWM_BY_TIMER

is not active.
If

IR_SEND_PIN

is specified (as c macro), it reduces program size and improves send timing for AVR. If you want to use a variable to specify send pin e.g. with

setSendPin(uint8_t aSendPinNumber)

, you must disable this

IR_SEND_PIN

macro. Then you can change send pin at any time before sending an IR frame. See also

Compile options / macros for this library

.

List of public IR code databases


http://www.harctoolbox.org/IR-resources.html

How To Make Arduino Multi Remote Control Car (Ep 02)
How To Make Arduino Multi Remote Control Car (Ep 02)

Staying on 2.x

Consider using the

original 2.4 release form 2017

or the last backwards compatible

2.8 version

for you project.
It may be sufficient and deals flawlessly with 32 bit IR codes.
If this doesn’t fit your case, be assured that 3.x is at least trying to be backwards compatible, so your old examples should still work fine.

Drawbacks

  • Only the following decoders are available:

    NEC


    Denon


    Panasonic


    JVC


    LG


    RC5


    RC6


    Samsung


    Sony
  • The call of

    irrecv.decode(&results)

    uses the old MSB first decoders like in 2.x and sets the 32 bit codes in

    results.value

    .
  • The old functions

    sendNEC()

    and

    sendJVC()

    are renamed to

    sendNECMSB()

    and

    sendJVCMSB()

    .
    Use them to send your

    old MSB-first 32 bit IR data codes

    .
  • No decoding by a (constant) 8/16 bit address and an 8 bit command.

Why *.hpp instead of *.cpp?


Every *.cpp file is compiled separately

by a call of the compiler exclusively for this cpp file. These calls are managed by the IDE / make system.
In the Arduino IDE the calls are executed when you click on Verify or Upload.

And now our problem with Arduino is:

How to set

compile options

for all *.cpp files, especially for libraries used?

IDE’s like

Sloeber

or

PlatformIO

support this by allowing to specify a set of options per project.
They add these options at each compiler call e.g.

-DTRACE

.

But Arduino lacks this feature.
So the

workaround

is not to compile all sources separately, but to concatenate them to one huge source file by including them in your source.
This is done by e.g.

#include "IRremote.hpp"

.

But why not

#include "IRremote.cpp"

?
Try it and you will see tons of errors, because each function of the *.cpp file is now compiled twice,
first by compiling the huge file and second by compiling the *.cpp file separately, like described above.
So using the extension cpp is not longer possible, and one solution is to use hpp as extension, to show that it is an included *.cpp file.
Every other extension e.g. cinclude would do, but hpp seems to be common sense.

Using the new *.hpp files

In order to support

compile options

more easily,
you must use the statement

#include

instead of

#include

in your main program (aka *.ino file with setup() and loop()).

In

all other files

you must use the following, to

prevent

multiple definitions

linker errors

:

#

define

USE_IRREMOTE_HPP_AS_PLAIN_INCLUDE

#

include

IRremote.hpp


Ensure that all macros in your main program are defined before any


#include

.
The following macros will definitely be overridden with default values otherwise:


  • RAW_BUFFER_LENGTH

  • IR_SEND_PIN

  • SEND_PWM_BY_TIMER

Receiving IR codes

Check for a

completly received IR frame

with:

if (IrReceiver.decode()) {}

This also decodes the received data.
After successful decoding, the IR data is contained in the IRData structure, available as

IrReceiver.decodedIRData

.

IR Receiver

Bức xạ hồng ngoại (IR), hay ánh sáng hồng ngoại, là dạng năng lượng bức xạ mà mắt người không nhìn thấy nhưng chúng ta có thể cảm nhận dưới dạng nhiệt. Mọi vật trong vũ trụ đều phát bức xạ IR ở mức nào đó, song có hai nguồn dễ thấy nhất là mặt trời và ngọn lửa.

IR là một loại bức xạ điện từ, một dải liên tục tần số được tạo ra khi các nguyên tử hấp thụ và sau đó giải phóng năng lượng. Từ tần số cao nhất đến thấp nhất, bức xạ điện từ bao gồm tia gamma, tia X, bức xạ tử ngoại, ánh sáng nhìn thấy, bức xạ hồng ngoại, vi sóng và sóng vô tuyến.

How To Make A Simple CAR Arduino iR Controlled Step by Step
How To Make A Simple CAR Arduino iR Controlled Step by Step

Problems with Neopixels, FastLed etc.

IRremote will not work right when you use

Neopixels

(aka WS2811/WS2812/WS2812B) or other libraries blocking interrupts for a longer time (> 50 µs).
Whether you use the Adafruit Neopixel lib, or FastLED, interrupts get disabled on many lower end CPUs like the basic Arduinos for longer than 50 µs.
In turn, this stops the IR interrupt handler from running when it needs to. See also this

video

.

One

workaround

is to wait for the IR receiver to be idle before you send the Neopixel data with

if (IrReceiver.isIdle()) { strip.show();}

.
This

prevents at least breaking a running IR transmission

and -depending of the update rate of the Neopixel- may work quite well.
There are some other solutions to this on more powerful processors,

see this page from Marc MERLIN

Unknown protocol

If your protocol seems not to be supported by this library, you may try the

IRMP library

.

Sending IR codes

If you have a device at hand which can generate the IR codes you want to work with (aka IR remote),

it is recommended

to receive the codes with the

ReceiveDemo example

, which will tell you on the serial output how to send them.

Protocol=LG Address=0x2 Command=0x3434 Raw-Data=0x23434E 28 bits MSB first
Send with: IrSender.sendLG(0x2, 0x3434, );

You will discover that

the address is a constant

and the commands sometimes are sensibly grouped.
If you are uncertain about the numbers of repeats to use for sending, is a good starting point. If this works, you can check lower values afterwards.

The codes found in the

irdb database

specify a

device

, a

subdevice

and a

function

. Most of the times, device and subdevice can be taken as upper and lower byte of the

address parameter

and function is the

command parameter

for the

new structured functions

with address, command and repeat-count parameters like e.g.

IrSender.sendNEC((device << 8) | subdevice, 0x19, 2)

.
An

exact mapping

can be found in the

IRP definition files for IR protocols

. “D” and “S” denotes device and subdevice and “F” denotes the function.


All sending functions support the sending of repeats

if sensible.
Repeat frames are sent at a fixed period determined by the protocol. e.g. 110 ms from start to start for NEC.
Keep in mind, that

there is no delay after the last sent mark

.
If you handle the sending of repeat frames by your own, you must insert sensible delays before the repeat frames to enable correct decoding.

The old send*Raw() functions for sending like e.g.

IrSender.sendNECRaw(0xE61957A8,2)

are kept for backward compatibility to

(old)

tutorials and unsupported as well as error prone.

how to make universal remote control at your home
how to make universal remote control at your home

How to convert old MSB first 32 bit IR data codes to new LSB first 32 bit IR data codes

For the new decoders for

NEC, Panasonic, Sony, Samsung and JVC

, the result

IrReceiver.decodedIRData.decodedRawData

is now

LSB-first

, as the definition of these protocols suggests!

To convert one into the other, you must reverse the byte/nibble positions and then reverse all bit positions of each byte/nibble or write it as one binary string and reverse/mirror it.
Example:

0xCB 34 01 02


0x20 10 43 BC

after nibble reverse

0x40 80 2C D3

after bit reverse of each nibble

Nibble reverse map:

 0->0   1->8   2->4   3->C
 4->2   5->A   6->6   7->E
 8->1   9->9   A->5   B->D
 C->3   D->B   E->7   F->F


0xCB340102

is binary

1100 1011 0011 0100 0000 0001 0000 0010

.

0x40802CD3

is binary

0100 0000 1000 0000 0010 1100 1101 0011

.
If you

read the first binary sequence backwards

(right to left), you get the second sequence.
You may use

bitreverseOneByte()

or

bitreverse32Bit()

for this.

Errors with using the 4.x versions for old tutorials

If you suffer from errors with old tutorial code including

IRremote.h

instead of

IRremote.hpp

, just try to rollback to

Version 2.4.0

.
Most likely your code will run and you will not miss the new features…

Programming the IR Receiver

Once you have the receiver connected, we can install the Arduino library and start programming. In the examples below, I’ll show you how to find the codes sent by your remote, how to find the IR protocol used by your remote, how to print key presses to the serial monitor or an LCD, and finally, how to control the Arduino’s output pins with a remote.

Install the IRremote Library

We’ll be using the IRremote library for all of the code examples below. You can download a ZIP file of the library from here.

To install the library from the ZIP file, open up the Arduino IDE, then go to Sketch > Include Library > Add .ZIP Library, then select the IRremote ZIP file that you downloaded from the link above.

Find the Codes for Your Remote

To find the key codes for your remote control, upload this code to your Arduino and open the serial monitor:


#include

const int RECV_PIN = 7; IRrecv irrecv(RECV_PIN); decode_results results; void setup(){ Serial.begin(9600); irrecv.enableIRIn(); irrecv.blink13(true); } void loop(){ if (irrecv.decode(&results)){ Serial.println(results.value, HEX); irrecv.resume(); } }

Now press each key on your remote and record the hexadecimal code printed for each key press.

Using the program above, I derived a table of keys and their corresponding codes from the remote that came with my HX1838 IR receiver and remote set. Note that you will receive a 0XFFFFFFFF code when you press a key continuously.

Key Code
CH- 0xFFA25D
CH 0xFF629D
CH+ 0xFFE21D
<< 0xFF22DD
>> 0xFF02FD
>|| 0xFFC23D
0xFFE01F
0xFFA857
EQ 0xFF906F
100+ 0xFF9867
200+ 0xFFB04F
0XFF6897
0xFF30CF
0xFF18E7
0xFF7A85
0xFF10EF
0xFF38C7
0xFF5AA5
0xFF42BD
0xFF4AB5
0xFF52AD

Find the Protocol Used by Your Remote

Knowing which protocol your remote uses can be useful if you want to work on some more advanced projects. Or you might just be curious. The program below will identify the protocol used by your remote. It should even work on most of the remote controls around your house.


#include

const int RECV_PIN = 7; IRrecv irrecv(RECV_PIN); decode_results results; void setup(){ Serial.begin(9600); irrecv.enableIRIn(); irrecv.blink13(true); } void loop(){ if (irrecv.decode(&results)){ Serial.println(results.value, HEX); switch (results.decode_type){ case NEC: Serial.println("NEC"); break ; case SONY: Serial.println("SONY"); break ; case RC5: Serial.println("RC5"); break ; case RC6: Serial.println("RC6"); break ; case DISH: Serial.println("DISH"); break ; case SHARP: Serial.println("SHARP"); break ; case JVC: Serial.println("JVC"); break ; case SANYO: Serial.println("SANYO"); break ; case MITSUBISHI: Serial.println("MITSUBISHI"); break ; case SAMSUNG: Serial.println("SAMSUNG"); break ; case LG: Serial.println("LG"); break ; case WHYNTER: Serial.println("WHYNTER"); break ; case AIWA_RC_T501: Serial.println("AIWA_RC_T501"); break ; case PANASONIC: Serial.println("PANASONIC"); break ; case DENON: Serial.println("DENON"); break ; default: case UNKNOWN: Serial.println("UNKNOWN"); break ; } irrecv.resume(); } }

Print Keys to the Serial Monitor

I extended the code above to print the key value instead of the hexadecimal code:


#include

const int RECV_PIN = 7; IRrecv irrecv(RECV_PIN); decode_results results; unsigned long key_value = 0; void setup(){ Serial.begin(9600); irrecv.enableIRIn(); irrecv.blink13(true); } void loop(){ if (irrecv.decode(&results)){ if (results.value == 0XFFFFFFFF) results.value = key_value; switch(results.value){ case 0xFFA25D: Serial.println("CH-"); break; case 0xFF629D: Serial.println("CH"); break; case 0xFFE21D: Serial.println("CH+"); break; case 0xFF22DD: Serial.println("|<<"); break; case 0xFF02FD: Serial.println(">>|"); break ; case 0xFFC23D: Serial.println(">|"); break ; case 0xFFE01F: Serial.println("-"); break ; case 0xFFA857: Serial.println("+"); break ; case 0xFF906F: Serial.println("EQ"); break ; case 0xFF6897: Serial.println("0"); break ; case 0xFF9867: Serial.println("100+"); break ; case 0xFFB04F: Serial.println("200+"); break ; case 0xFF30CF: Serial.println("1"); break ; case 0xFF18E7: Serial.println("2"); break ; case 0xFF7A85: Serial.println("3"); break ; case 0xFF10EF: Serial.println("4"); break ; case 0xFF38C7: Serial.println("5"); break ; case 0xFF5AA5: Serial.println("6"); break ; case 0xFF42BD: Serial.println("7"); break ; case 0xFF4AB5: Serial.println("8"); break ; case 0xFF52AD: Serial.println("9"); break ; } key_value = results.value; irrecv.resume(); } }

If your remote sends different codes than the ones in the table above, just replace the hex code in each line where it says:


case 0xFFA25D: Serial.println(“CH-“);

In these lines, when the hex code

0xFFA25D

is received, the Arduino prints “CH-“.

How the Code Works

For any IR communication using the IRremote library, first we need to create an object called

irrecv

and specify the pin number where the IR receiver is connected (line 3). This object will take care of the protocol and processing of the information from the receiver.

The next step is to create an object called

results

, from the

decode_results

class, which will be used by the

irrecv

object to share the decoded information with our application (line 5).

In the

void setup()

block, first we configure the serial monitor baud rate. Next we start the IR receiver by calling the

IRrecv

member function

enableIRIn()

(line 10).

The

irrecv.blink13(true)

function on line 11 will blink the Arduino’s on board LED every time the receiver gets a signal from the remote control, which is useful for debugging.

In the

void loop()

block, the function

irrecv.decode

will return true if a code is received and the program will execute the code in the if statement. The received code is stored in

results.value

. Then I used a switch to handle each IR code and print the corresponding key value.

Before the switch block starts there is a conditional block:


if (results.value == 0XFFFFFFFF) results.value = key_value;

If we receive 0XFFFFFFFF from the remote, it means a repetition of the previous key. So in order to handle the repeat key pattern, I am storing the hex code in a global variable

key_value

every time a code is received:


key_value = results.value;

When you receive a repeat pattern, then the previously stored value is used as the current key press.

At the end of the

void loop()

section, we call

irrecv.resume()

to reset the receiver and prepare it to receive the next code.

How to decode any RF signal remote in Arduino | Arduino Project| ALPHA Lab
How to decode any RF signal remote in Arduino | Arduino Project| ALPHA Lab

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Infrared (IR) communication is a widely used and easy to implement wireless technology that has many useful applications. The most prominent examples in day to day life are TV/video remote controls, motion sensors, and infrared thermometers.

There are plenty of interesting Arduino projects that use IR communication too. With a simple IR transmitter and receiver, you can make remote controlled robots, distance sensors, heart rate monitors, DSLR camera remote controls, TV remote controls, and lots more.

In this tutorial I’ll first explain what infrared is and how it works. Then I’ll show you how to set up an IR receiver and remote on an Arduino. I’ll also show you how to use virtually any IR remote (like the one for your TV) to control things connected to the Arduino.

Watch the video for this tutorial here:

Now let’s get into the details…

Application example: blink some LEDs with the IR remote controller

In this application, what we want to do is simply to toggle a red LED when we press on button 2, and toggle a green LED when we press on button play/pause.

Circuit

Let’s build this circuit.

We use the same circuit as before, and add 2 LEDs:

  • For each LED, plug the shorter leg to GND.
  • plug the longer leg to a 220Ohm resistor.
  • Connect the other leg of the resistor to pin 12 (red LED) and pin 11 (green LED).

Code

Here is the code for the application.

#include

#define IR_RECEIVE_PIN 8 #define IR_BUTTON_2 24 #define IR_BUTTON_PLAY_PAUSE 64 #define RED_LED_PIN 12 #define GREEN_LED_PIN 11 byte redLedState = LOW; byte greenLedState = LOW; void setup() { IrReceiver.begin(IR_RECEIVE_PIN); pinMode(RED_LED_PIN, OUTPUT); pinMode(GREEN_LED_PIN, OUTPUT); } void loop() { if (IrReceiver.decode()) { IrReceiver.resume(); int command = IrReceiver.decodedIRData.command; switch (command) { case IR_BUTTON_2: { redLedState = (redLedState == LOW) ? HIGH : LOW; digitalWrite(RED_LED_PIN, redLedState); break; } case IR_BUTTON_PLAY_PAUSE: { greenLedState = (greenLedState == LOW) ? HIGH: LOW; digitalWrite(GREEN_LED_PIN, greenLedState); break; } default: { // do nothing } } } }

If you run this, and press on button “play/pause”, you will see the green LED powered on. If you press again, the green LED will be powered off. Etc. The same applies for the red LED when you press on the button “2”.

And let’s now break the code down.

#include

#define IR_RECEIVE_PIN 8 #define IR_BUTTON_2 24 #define IR_BUTTON_PLAY_PAUSE 64

As we have already mapped the buttons, we reuse the same defines we previously wrote. Here we just need buttons “2” and “play/pause” so I’ve only included the numbers for those 2 buttons.

#define RED_LED_PIN 12 #define GREEN_LED_PIN 11 byte redLedState = LOW; byte greenLedState = LOW;

We set some defines for the LED’s pin numbers. We also keep the state of both LEDs in a global variable, so we will be able to retrieve and toggle this state.

void setup() { IrReceiver.begin(IR_RECEIVE_PIN); pinMode(RED_LED_PIN, OUTPUT); pinMode(GREEN_LED_PIN, OUTPUT); }

In the setup() we initialize the IR receiver component, and the 2 LEDs with pinMode() function and OUTPUT mode.

void loop() { if (IrReceiver.decode()) { IrReceiver.resume(); int command = IrReceiver.decodedIRData.command; switch (command) {

This is exactly the same as what we did before. We check if there is some data to read from the IR receiver. If yes, we get the data, we resume the sensor, and we check which button was pressed with a switch structure.

case IR_BUTTON_2: { redLedState = (redLedState == LOW) ? HIGH : LOW; digitalWrite(RED_LED_PIN, redLedState); break; }

When the button “2” is pressed, we toggle the LED state with a one-liner: (redLedState == LOW) will be evaluated to true or false. If it’s true (variable is LOW), we set the variable to HIGH, and if it’s false (variable is HIGH), we set the variable to LOW.

After that we apply the new state to the LED with digitalWrite().

That’s it! If you know how to toggle an LED, and how to get data from an IR receiver, combining the 2 together is really easy.

case IR_BUTTON_PLAY_PAUSE: { greenLedState = (greenLedState == LOW) ? HIGH: LOW; digitalWrite(GREEN_LED_PIN, greenLedState); break; }

We do the same thing for the green LED, when we press on the “play/pause” button.

default: { // do nothing } } } }

And finally we have the switch default, which we don’t use here.

HOW TO CONTROL 4WD ROBOT SMART CAR USING IR REMOTE WITH ARDUINO
HOW TO CONTROL 4WD ROBOT SMART CAR USING IR REMOTE WITH ARDUINO

New features with version 3.x


  • Any pin

    can be used for sending -if

    SEND_PWM_BY_TIMER

    is not defined- and receiving.
  • Feedback LED can be activated for sending / receiving.
  • An 8/16 bit **

    command

    value as well as an 16 bit

    address

    and a protocol number is provided for decoding (instead of the old 32 bit value).
  • Protocol values comply to

    protocol standards

    .
    NEC, Panasonic, Sony, Samsung and JVC decode & send LSB first.
  • Supports

    Universal Distance protocol

    , which covers a lot of previous unknown protocols.
  • Compatible with

    tone()

    library. See the

    ReceiveDemo

    example.
  • Simultaneous sending and receiving. See the

    SendAndReceive

    example.
  • Supports

    more platforms

    .
  • Allows for the generation of non PWM signal to just

    simulate an active low receiver signal

    for direct connect to existent receiving devices without using IR.
  • Easy protocol configuration,

    directly in your

    source code


    .
    Reduces memory footprint and decreases decoding time.
  • Contains a

    very small NEC only decoder

    , which

    does not require any timer resource

    .


-> Feature comparison of 5 Arduino IR libraries

.

Converting your 2.x program to the 4.x version

Starting with the 3.1 version,

the generation of PWM for sending is done by software

, thus saving the hardware timer and

enabling arbitrary output pins for sending

.
If you use an (old) Arduino core that does not use the

-flto

flag for compile, you can activate the line

#define SUPPRESS_ERROR_MESSAGE_FOR_BEGIN

in IRRemote.h, if you get false error messages regarding begin() during compilation.


  • IRreceiver

    and

    IRsender

    object have been added and can be used without defining them, like the well known Arduino

    Serial

    object.

  • Just remove the line

    IRrecv IrReceiver(IR_RECEIVE_PIN);

    and/or

    IRsend IrSender;

    in your program, and replace all occurrences of

    IRrecv.

    or

    irrecv.

    with

    IrReceiver

    and replace all

    IRsend

    or

    irsend

    with

    IrSender

    .

  • Since the decoded values are now in

    IrReceiver.decodedIRData

    and not in

    results

    any more, remove the line

    decode_results results

    or similar.

  • Like for the Serial object, call


    IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK)


    or

    IrReceiver.begin(IR_RECEIVE_PIN, DISABLE_LED_FEEDBACK)

    instead of the

    IrReceiver.enableIRIn()

    or

    irrecv.enableIRIn()

    in setup().
    For sending, call

    IrSender.begin();

    or

    IrSender.begin(DISABLE_LED_FEEDBACK);

    in setup().
    If IR_SEND_PIN is not defined (before the line

    #include

    ) you must use e.g.

    IrSender.begin(3, ENABLE_LED_FEEDBACK, USE_DEFAULT_FEEDBACK_LED_PIN);

  • Old

    decode(decode_results *aResults)

    function is replaced by simple

    decode()

    . So if you have a statement

    if(irrecv.decode(&results))

    replace it with

    if (IrReceiver.decode())

    .

  • The decoded result is now in in

    IrReceiver.decodedIRData

    and not in

    results

    any more, therefore replace any occurrences of

    results.value

    and

    results.decode_type

    (and similar) to

    IrReceiver.decodedIRData.decodedRawData

    and

    IrReceiver.decodedIRData.protocol

    .

  • Overflow, Repeat and other flags are now in


    IrReceiver.receivedIRData.flags


    .

  • Seldom used:

    results.rawbuf

    and

    results.rawlen

    must be replaced by

    IrReceiver.decodedIRData.rawDataPtr->rawbuf

    and

    IrReceiver.decodedIRData.rawDataPtr->rawlen

    .

  • The 5 protocols

    NEC, Panasonic, Sony, Samsung and JVC

    have been converted to LSB first. Send functions for sending old MSB data for

    NEC

    and

    JVC

    were renamed to

    sendNECMSB

    , and

    sendJVCMSB()

    . The old

    sendSAMSUNG()

    and

    sendSony()

    MSB functions are still available. The old MSB version of

    sendPanasonic()

    function was deleted, since it had bugs nobody recognized.
    For converting MSB codes to LSB see

    below

    .

Example

Old 2.x program:
#

include

IRremote.h

#

define

RECV_PIN

IRrecv

irrecv

(RECV_PIN); decode_results results;

void

setup

() { ... irrecv.

enableIRIn

();

//

Start the receiver

}

void

loop

() {

if

(irrecv.

decode

(&results)) { Serial.

println

(results.

value

, HEX); ... irrecv.

resume

();

//

Receive the next value

} ... }
New 4.x program:
#

include

IRremote.hpp

#

define

IR_RECEIVE_PIN

void

setup

() { ... IrReceiver.

begin

(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);

//

Start the receiver

}

void

loop

() {

if

(IrReceiver.

decode

()) { Serial.

println

(IrReceiver.

decodedIRData

.

decodedRawData

, HEX);

//

Print "old" raw data

//

USE NEW 3.x FUNCTIONS

IrReceiver.

printIRResultShort

(&Serial);

//

Print complete received data in one line

IrReceiver.

printIRSendUsage

(&Serial);

//

Print the statement required to send this data

... IrReceiver.

resume

();

//

Enable receiving of the next value

} ... }

Arduino circuit with IR receiver and IR remote controller

For the circuit you will need:

  • Arduino board (any version is fine, I will use Arduino Uno).
  • breadboard.
  • IR receiver. This will receive data from the remote controller and send it to the Arduino board.
  • IR remote controller.

To build the circuit:

You are learning how to use Arduino to build your own projects?

Check out Arduino For Beginners and learn step by step.

  • Place the IR receiver on the breadboard, with each pin on an independent line, so they are not connected with each other.
  • Connect the GND pin of the IR receiver to one GND pin of the Arduino.
  • Connect the Vcc or power pin of the IR receiver to the 5V pin of the Arduino.
  • For the data pin, connect it to one digital pin of the Arduino (here digital pin number 8).

(more info on Arduino Uno pins)

Note that the IR receiver you have may be different from the one you see here on the picture. The order of the pins can also be different. The important thing is to locate first GND, Vcc, and data pins, and then connect them accordingly to the correct Arduino pins.

Master Led Control With A IR Remote: Easy Tinkercad Circuits Tips For Beginners 2024!
Master Led Control With A IR Remote: Easy Tinkercad Circuits Tips For Beginners 2024!

Flipper Zero


Flipper IRDB Database


Flipper decoding


IRremote decoding

Samsung32
Samsung

NEC
NEC

NECext
ONKYO

and ID is MSB of address.address: 8A 02 20 00command: 56 03 00 00->

IRremote:

Address 0x6A8, sendPanasonic (for 02 20) and Command 0x35



Tiny NEC receiver and sender

For applications only requiring NEC, NEC variants or FAST -see below- protocol, there is a special receiver / sender included,
which has very

small code size of 500 bytes and does NOT require any timer

.

Check out the

TinyReceiver

and

IRDispatcherDemo

examples.
Take care to include

TinyIRReceiver.hpp

or

TinyIRSender.hpp

instead of

IRremote.hpp

.

TinyIRReceiver usage

//

#define USE_ONKYO_PROTOCOL // Like NEC, but take the 16 bit address and command each as one 16 bit value and not as 8 bit normal and 8 bit inverted value.

//

#define USE_FAST_PROTOCOL // Use FAST protocol instead of NEC / ONKYO

#include

TinyIRReceiver.hpp

void

setup

() {

initPCIInterruptForTinyReceiver

();

//

Enables the interrupt generation on change of IR input signal

}

void

loop

() {

if

(TinyIRReceiverData.

justWritten

) { TinyIRReceiverData.

justWritten

=

false

;

printTinyReceiverResultMinimal

(&Serial); } }

TinyIRSender usage

#

include

TinyIRSender.hpp

void

setup

() {

sendNECMinimal

(, ,

11

, );

//

Send address 0 and command 11 on pin 3 with 2 repeats.

}

void

loop

() {}

Another tiny receiver and sender

supporting more protocols

can be found

here

.

The FAST protocol

The FAST protocol is a proprietary modified JVC protocol

without address, with parity and with a shorter header

.
It is meant to have a quick response to the event which sent the protocol frame on another board.
FAST takes

21 ms for sending

and is sent at a

50 ms period

.
It has full 8 bit parity for error detection.

FAST protocol characteristics:

  • Bit timing is like JVC
  • The header is shorter, 3156 µs vs. 12500 µs
  • No address and 16 bit data, interpreted as 8 bit command and 8 bit inverted command, leading to a fixed protocol length of (6 + (16 * 3) + 1) * 526 = 55 * 526 = 28930 microseconds or 29 ms.
  • Repeats are sent as complete frames but in a 50 ms period / with a 21 ms distance.

Sending FAST protocol with IRremote

#

define

IR_SEND_PIN

#

include

IRremote.hpp

void

setup

() {

sendFAST

(

11

, );

//

Send command 11 on pin 3 with 2 repeats.

}

void

loop

() {}

Sending FAST protocol with TinyIRSender

#

define

USE_FAST_PROTOCOL

//

Use FAST protocol. No address and 16 bit data, interpreted as 8 bit command and 8 bit inverted command

#include

TinyIRSender.hpp

void

setup

() {

sendFAST

(,

11

, );

//

Send command 11 on pin 3 with 2 repeats.

}

void

loop

() {}

The FAST protocol can be received by IRremote and TinyIRReceiver.

FAQ and hints

decodedIRData structure

struct

IRData

{

decode_type_t

protocol;

//

UNKNOWN, NEC, SONY, RC5, PULSE_DISTANCE, ...

uint16_t

address;

//

Decoded address

uint16_t

command;

//

Decoded command

uint16_t

extra;

//

Used for Kaseikyo unknown vendor ID. Ticks used for decoding Distance protocol.

uint16_t

numberOfBits;

//

Number of bits received for data (address + command + parity) - to determine protocol length if different length are possible.

uint8_t

flags;

//

IRDATA_FLAGS_IS_REPEAT, IRDATA_FLAGS_WAS_OVERFLOW etc. See IRDATA_FLAGS_* definitions

IRRawDataType decodedRawData;

//

Up to 32 (64 bit for 32 bit CPU architectures) bit decoded raw data, used for sendRaw functions.

uint32_t

decodedRawDataArray[RAW_DATA_ARRAY_SIZE];

//

32 bit decoded raw data, to be used for send function.

irparams_struct *rawDataPtr;

//

Pointer of the raw timing data to be decoded. Mainly the data buffer filled by receiving ISR.

};
Flags

This is the

list of flags

contained in the flags field.
Check it with e.g.

if(IrReceiver.decodedIRData.flags & IRDATA_FLAGS_IS_REPEAT)

.

Flag name
Description

IRDATA_FLAGS_IS_REPEAT
The gap between the preceding frame is as smaller than the maximum gap expected for a repeat. !!!We do not check for changed command or address, because it is almost not possible to press 2 different buttons on the remote within around 100 ms!!!

IRDATA_FLAGS_IS_AUTO_REPEAT
The current repeat frame is a repeat, that is always sent after a regular frame and cannot be avoided. Only specified for protocols DENON, and LEGO.

IRDATA_FLAGS_PARITY_FAILED
The current (autorepeat) frame violated parity check.

IRDATA_FLAGS_TOGGLE_BIT
Is set if RC5 or RC6 toggle bit is set.

IRDATA_FLAGS_EXTRA_INFO
There is extra info not contained in address and data (e.g. Kaseikyo unknown vendor ID, or in decodedRawDataArray).

IRDATA_FLAGS_WAS_OVERFLOW
irparams.rawlen is set to 0 in this case to avoid endless OverflowFlag.

IRDATA_FLAGS_IS_MSB_FIRST
This value is mainly determined by the (known) protocol.

To access the RAW data, use:

auto

myRawdata= IrReceiver.decodedIRData.decodedRawData;

The definitions for the

IrReceiver.decodedIRData.flags

are described

here

.

Print all fields:
IrReceiver.printIRResultShort(&Serial);
Print the raw timing data received:
IrReceiver.printIRResultRawFormatted(&Serial, 

true

);`

The raw data depends on the internal state of the Arduino timer in relation to the received signal and might therefore be slightly different each time. (resolution problem). The decoded values are the interpreted ones which are tolerant to such slight differences!

Print how to send the received data:
IrReceiver.printIRSendUsage(&Serial);
IR Remotes & Microcontrollers - Arduino & ESP32
IR Remotes & Microcontrollers – Arduino & ESP32

Hardware-PWM signal generation for sending

If you define

SEND_PWM_BY_TIMER

, the send PWM signal is forced to be generated by a hardware timer on most platforms.
By default, the same timer as for the receiver is used.
Since each hardware timer has its dedicated output pin(s), you must change timer or timer sub-specifications to change PWM output pin. See

private/IRTimer.hpp


Exeptions

are currently

ESP32, ARDUINO_ARCH_RP2040, PARTICLE and ARDUINO_ARCH_MBED

, where

PWM generation does not require a timer

.

Flipper Zero


Flipper IRDB Database


Flipper decoding


IRremote decoding

Samsung32
Samsung

NEC
NEC

NECext
ONKYO

and ID is MSB of address.address: 8A 02 20 00command: 56 03 00 00->

IRremote:

Address 0x6A8, sendPanasonic (for 02 20) and Command 0x35



Tiny NEC receiver and sender

For applications only requiring NEC, NEC variants or FAST -see below- protocol, there is a special receiver / sender included,
which has very

small code size of 500 bytes and does NOT require any timer

.

Check out the

TinyReceiver

and

IRDispatcherDemo

examples.
Take care to include

TinyIRReceiver.hpp

or

TinyIRSender.hpp

instead of

IRremote.hpp

.

TinyIRReceiver usage

//

#define USE_ONKYO_PROTOCOL // Like NEC, but take the 16 bit address and command each as one 16 bit value and not as 8 bit normal and 8 bit inverted value.

//

#define USE_FAST_PROTOCOL // Use FAST protocol instead of NEC / ONKYO

#include

TinyIRReceiver.hpp

void

setup

() {

initPCIInterruptForTinyReceiver

();

//

Enables the interrupt generation on change of IR input signal

}

void

loop

() {

if

(TinyIRReceiverData.

justWritten

) { TinyIRReceiverData.

justWritten

=

false

;

printTinyReceiverResultMinimal

(&Serial); } }

TinyIRSender usage

#

include

TinyIRSender.hpp

void

setup

() {

sendNECMinimal

(, ,

11

, );

//

Send address 0 and command 11 on pin 3 with 2 repeats.

}

void

loop

() {}

Another tiny receiver and sender

supporting more protocols

can be found

here

.

The FAST protocol

The FAST protocol is a proprietary modified JVC protocol

without address, with parity and with a shorter header

.
It is meant to have a quick response to the event which sent the protocol frame on another board.
FAST takes

21 ms for sending

and is sent at a

50 ms period

.
It has full 8 bit parity for error detection.

FAST protocol characteristics:

  • Bit timing is like JVC
  • The header is shorter, 3156 µs vs. 12500 µs
  • No address and 16 bit data, interpreted as 8 bit command and 8 bit inverted command, leading to a fixed protocol length of (6 + (16 * 3) + 1) * 526 = 55 * 526 = 28930 microseconds or 29 ms.
  • Repeats are sent as complete frames but in a 50 ms period / with a 21 ms distance.

Sending FAST protocol with IRremote

#

define

IR_SEND_PIN

#

include

IRremote.hpp

void

setup

() {

sendFAST

(

11

, );

//

Send command 11 on pin 3 with 2 repeats.

}

void

loop

() {}

Sending FAST protocol with TinyIRSender

#

define

USE_FAST_PROTOCOL

//

Use FAST protocol. No address and 16 bit data, interpreted as 8 bit command and 8 bit inverted command

#include

TinyIRSender.hpp

void

setup

() {

sendFAST

(,

11

, );

//

Send command 11 on pin 3 with 2 repeats.

}

void

loop

() {}

The FAST protocol can be received by IRremote and TinyIRReceiver.

FAQ and hints

Using IR Remote Controls with the Arduino
Using IR Remote Controls with the Arduino

Multiple IR receivers

IRreceiver consists of one timer triggered function reading the digital IR signal value from one pin every 50 µs.
So

multiple IR receivers

can only be used by connecting the output pins of several IR receivers together.
The IR receivers use an NPN transistor as output device with just a 30k resistor to VCC.
This is almost “open collector” and allows connecting of several output pins to one Arduino input pin.
But keep in mind, that any weak / disturbed signal from one of the receivers will in turn also disturb a good signal from another one.

Minimal CPU clock frequency

For receiving, the

minimal CPU clock frequency is 4 MHz

, since the 50 µs timer ISR (Interrupt Service Routine) takes around 12 µs on a 16 MHz ATmega.
The TinyReceiver, which reqires no polling, runs with 1 MHz.
For sending, the

default software generated PWM has problems on AVR running with 8 MHz

. The PWM frequency is around 30 instead of 38 kHz and RC6 is not reliable. You can switch to timer PWM generation by

#define SEND_PWM_BY_TIMER

.

Arduino Tutorial 64: Understanding and Using the Infrared (IR) Remote to Control a Project
Arduino Tutorial 64: Understanding and Using the Infrared (IR) Remote to Control a Project

About IR Remote Control

An IR control system includes two components:

  • IR remote controller
  • IR receiver

An IR kit usually includes two above components.

IR remote controller

The IR remote controller is a handheld device that emits infrared signals. The IR remote controller consists of a keypad with various buttons:

  • Each button on the remote controller corresponds to a specific function or command.
  • When a button is pressed, the remote emits an infrared signal that carries a unique code or pattern associated with the pressed button.
  • These infrared signals are not visible to the human eye as they are in the infrared spectrum.

IR Receiver

The IR receiver module is a sensor that detects and receives the infrared signals emitted by the remote controller.

The infrared receiver detects the incoming infrared signals and converts them into the code (command) representing the button pressed on the remote controller.

The IR Receiver can be a sensor or a module. You can use the following choices:

  • IR Receiver Module only
  • IR Receiver Sensor only
  • IR Receiver Sensor + Adapter
IR Receiver Pinout

IR receiver module or sensor has three pins:

  • VCC pin: Connect this pin to the 3.3V or 5V pin of the Arduino or external power source.
  • GND pin: Connect this pin to GND pin of the Arduino or external power source..
  • OUT (Output) pin: This pin is the output pin of the IR receiver module. Connected to a digital input pin on the Arduino.

How It Works

When user presses a button on the IR remote controller

  • The IR remote controller encodes the command corresponding to the button to the infrared signal via a specific protocol
  • The IR remote controller emits the encoded infrared signal
  • The IR receiver receives the encoded infrared signal
  • The IR receiver decoded the encoded infrared signal in to the command
  • The Arduino reads the command from the IR receiver
  • The Arduino maps the command to the key pressed

It seems to be complicated but don’t worry. With the help of DIYables_IRcontroller library, it is a piece of cake.

New features with version 3.x


  • Any pin

    can be used for sending -if

    SEND_PWM_BY_TIMER

    is not defined- and receiving.
  • Feedback LED can be activated for sending / receiving.
  • An 8/16 bit **

    command

    value as well as an 16 bit

    address

    and a protocol number is provided for decoding (instead of the old 32 bit value).
  • Protocol values comply to

    protocol standards

    .
    NEC, Panasonic, Sony, Samsung and JVC decode & send LSB first.
  • Supports

    Universal Distance protocol

    , which covers a lot of previous unknown protocols.
  • Compatible with

    tone()

    library. See the

    ReceiveDemo

    example.
  • Simultaneous sending and receiving. See the

    SendAndReceive

    example.
  • Supports

    more platforms

    .
  • Allows for the generation of non PWM signal to just

    simulate an active low receiver signal

    for direct connect to existent receiving devices without using IR.
  • Easy protocol configuration,

    directly in your

    source code


    .
    Reduces memory footprint and decreases decoding time.
  • Contains a

    very small NEC only decoder

    , which

    does not require any timer resource

    .


-> Feature comparison of 5 Arduino IR libraries

.

Converting your 2.x program to the 4.x version

Starting with the 3.1 version,

the generation of PWM for sending is done by software

, thus saving the hardware timer and

enabling arbitrary output pins for sending

.
If you use an (old) Arduino core that does not use the

-flto

flag for compile, you can activate the line

#define SUPPRESS_ERROR_MESSAGE_FOR_BEGIN

in IRRemote.h, if you get false error messages regarding begin() during compilation.


  • IRreceiver

    and

    IRsender

    object have been added and can be used without defining them, like the well known Arduino

    Serial

    object.

  • Just remove the line

    IRrecv IrReceiver(IR_RECEIVE_PIN);

    and/or

    IRsend IrSender;

    in your program, and replace all occurrences of

    IRrecv.

    or

    irrecv.

    with

    IrReceiver

    and replace all

    IRsend

    or

    irsend

    with

    IrSender

    .

  • Since the decoded values are now in

    IrReceiver.decodedIRData

    and not in

    results

    any more, remove the line

    decode_results results

    or similar.

  • Like for the Serial object, call


    IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK)


    or

    IrReceiver.begin(IR_RECEIVE_PIN, DISABLE_LED_FEEDBACK)

    instead of the

    IrReceiver.enableIRIn()

    or

    irrecv.enableIRIn()

    in setup().
    For sending, call

    IrSender.begin();

    or

    IrSender.begin(DISABLE_LED_FEEDBACK);

    in setup().
    If IR_SEND_PIN is not defined (before the line

    #include

    ) you must use e.g.

    IrSender.begin(3, ENABLE_LED_FEEDBACK, USE_DEFAULT_FEEDBACK_LED_PIN);

  • Old

    decode(decode_results *aResults)

    function is replaced by simple

    decode()

    . So if you have a statement

    if(irrecv.decode(&results))

    replace it with

    if (IrReceiver.decode())

    .

  • The decoded result is now in in

    IrReceiver.decodedIRData

    and not in

    results

    any more, therefore replace any occurrences of

    results.value

    and

    results.decode_type

    (and similar) to

    IrReceiver.decodedIRData.decodedRawData

    and

    IrReceiver.decodedIRData.protocol

    .

  • Overflow, Repeat and other flags are now in


    IrReceiver.receivedIRData.flags


    .

  • Seldom used:

    results.rawbuf

    and

    results.rawlen

    must be replaced by

    IrReceiver.decodedIRData.rawDataPtr->rawbuf

    and

    IrReceiver.decodedIRData.rawDataPtr->rawlen

    .

  • The 5 protocols

    NEC, Panasonic, Sony, Samsung and JVC

    have been converted to LSB first. Send functions for sending old MSB data for

    NEC

    and

    JVC

    were renamed to

    sendNECMSB

    , and

    sendJVCMSB()

    . The old

    sendSAMSUNG()

    and

    sendSony()

    MSB functions are still available. The old MSB version of

    sendPanasonic()

    function was deleted, since it had bugs nobody recognized.
    For converting MSB codes to LSB see

    below

    .

Example

Old 2.x program:
#

include

IRremote.h

#

define

RECV_PIN

IRrecv

irrecv

(RECV_PIN); decode_results results;

void

setup

() { ... irrecv.

enableIRIn

();

//

Start the receiver

}

void

loop

() {

if

(irrecv.

decode

(&results)) { Serial.

println

(results.

value

, HEX); ... irrecv.

resume

();

//

Receive the next value

} ... }
New 4.x program:
#

include

IRremote.hpp

#

define

IR_RECEIVE_PIN

void

setup

() { ... IrReceiver.

begin

(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);

//

Start the receiver

}

void

loop

() {

if

(IrReceiver.

decode

()) { Serial.

println

(IrReceiver.

decodedIRData

.

decodedRawData

, HEX);

//

Print "old" raw data

//

USE NEW 3.x FUNCTIONS

IrReceiver.

printIRResultShort

(&Serial);

//

Print complete received data in one line

IrReceiver.

printIRSendUsage

(&Serial);

//

Print the statement required to send this data

... IrReceiver.

resume

();

//

Enable receiving of the next value

} ... }
How to use IR receiver + TV remote with Arduino. And how to download IR Library and add Library.
How to use IR receiver + TV remote with Arduino. And how to download IR Library and add Library.

Incompatibilities to other libraries and Arduino commands like tone() and analogWrite()

If you use a library which requires the same timer as IRremote, you have a problem, since

the timer resource cannot be shared simultaneously

by both libraries.

Change timer

The best approach is to change the timer used for IRremote, which can be accomplished by specifying the timer before

#include

.
The timer specifications available for your board can be found in

private/IRTimer.hpp

.

//

Arduino Mega

#elif

defined

(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) #

if

!defined(IR_USE_AVR_TIMER1) && !defined(IR_USE_AVR_TIMER2) && !defined(IR_USE_AVR_TIMER3) && !defined(IR_USE_AVR_TIMER4) && !defined(IR_USE_AVR_TIMER5)

//

#define IR_USE_AVR_TIMER1 // send pin = pin 11

#define IR_USE_AVR_TIMER2

//

send pin = pin 9

//

#define IR_USE_AVR_TIMER3 // send pin = pin 5

//

#define IR_USE_AVR_TIMER4 // send pin = pin 6

//

#define IR_USE_AVR_TIMER5 // send pin = pin 46

# endif

Here you see the Arduino Mega board and the available specifications are

IR_USE_AVR_TIMER[1,2,3,4,5]

.
You

just have to include a line

e.g.

#define IR_USE_AVR_TIMER3

before

#include

to enable timer 3.

But be aware that the new timer in turn might be incompatible with other libraries or commands.
For other boards/platforms you must look for the appropriate section guarded by e.g.

#elif defined(ESP32)

.

Stop and start timer

Another approach can be to share the timer

sequentially

if their functionality is used only for a short period of time like for the

Arduino tone() command

.
An example can be seen

here

, where the timer settings for IR receive are restored after the tone has stopped.
For this we must call

IrReceiver.start()

or better

IrReceiver.start(microsecondsOfToneDuration)

.
This only works since each call to

tone()

completely initializes the timer 2 used by the

tone()

command.

Ambiguous protocols

NEC, Extended NEC, ONKYO

The

NEC protocol

is defined as 8 bit address and 8 bit command. But the physical address and data fields are each 16 bit wide.
The additional 8 bits are used to send the inverted address or command for parity checking.
The

extended NEC protocol

uses the additional 8 parity bit of address for a 16 bit address, thus disabling the parity check for address.
The

ONKYO protocol

in turn uses the additional 8 parity bit of address and command for a 16 bit address and command.

The decoder reduces the 16 bit values to 8 bit ones if the parity is correct.
If the parity is not correct, it assumes no parity error, but takes the values as 16 bit values without parity assuming extended NEC or extended NEC protocol protocol.

But now we have a problem when we want to receive e.g. the

16 bit

address 0x00FF or 0x32CD!
The decoder interprets this as a NEC 8 bit address 0x00 / 0x32 with correct parity of 0xFF / 0xCD and reduces it to 0x00 / 0x32.

One way to handle this, is to force the library to

always

use the ONKYO protocol interpretation by using

#define DECODE_ONKYO

.
Another way is to check if

IrReceiver.decodedIRData.protocol

is NEC and not ONKYO and to revert the parity reducing manually.

NEC, NEC2

On a long press, the

NEC protocol

does not repeat its frame, it sends a special short repeat frame.
This enables an easy distinction between long presses and repeated presses and saves a bit of battery energy.
This behavior is quite unique for NEC and its derived protocols like LG.

So there are of course also remote control systems, which uses the NEC protocol but on a long press just repeat the first frame instead of sending the special short repeat frame. We named this the

NEC2

protocol and it is sent with

sendNEC2()

.
But be careful, the NEC2 protocol can only be detected by the NEC library decoder

after

the first frame and if you do a long press!

EEVblog #506 - IR Remote Control Arduino Protocol Tutorial
EEVblog #506 – IR Remote Control Arduino Protocol Tutorial

How to deal with protocols not supported by IRremote

If you do not know which protocol your IR transmitter uses, you have several choices.

Examples for this library

The examples are available at File > Examples > Examples from Custom Libraries / IRremote.
In order to fit the examples to the 8K flash of ATtiny85 and ATtiny88, the

Arduino library ATtinySerialOut

is required for this CPU’s.

SimpleReceiver + SimpleSender

The


SimpleReceiver


and


SimpleSender


examples are a good starting point.
A simple example can be tested online with

WOKWI

.

TinyReceiver + TinySender

If

code size

or

timer usage

matters, look at these examples.
The


TinyReceiver


example uses the

TinyIRReceiver

library
which can

only receive NEC, Extended NEC, ONKYO and FAST protocols, but does not require any timer

.
They use pin change interrupt for on the fly decoding, which is the reason for the restricted protocol choice.
TinyReceiver can be tested online with

WOKWI

.

The


TinySender


example uses the

TinyIRSender

library which can

only send NEC, ONKYO and FAST protocols

.
It sends NEC protocol codes in standard format with 8 bit address and 8 bit command as in SimpleSender example.
Saves 780 bytes program memory and 26 bytes RAM compared to SimpleSender, which does the same, but uses the IRRemote library (and is therefore much more flexible).

SmallReceiver

If the protocol is not NEC and code size matters, look at this

example

.

ReceiveDemo + AllProtocolsOnLCD


ReceiveDemo

receives all protocols and

generates a beep with the Arduino tone() function

on each packet received.
Long press of one IR button (receiving of multiple repeats for one command) is detected.

AllProtocolsOnLCD

additionally

displays the short result on a 1602 LCD

. The LCD can be connected parallel or serial (I2C).
By connecting debug pin to ground, you can force printing of the raw values for each frame. The pin number of the debug pin is printed during setup, because it depends on board and LCD connection type.
This example also serves as an

example how to use IRremote and tone() together

.

ReceiveDump

Receives all protocols and dumps the received signal in different flavors including Pronto format. Since the printing takes much time, repeat signals may be skipped or interpreted as UNKNOWN.

SendDemo

Sends all available protocols at least once.

SendAndReceive

Demonstrates

receiving while sending

.

ReceiveAndSend

Record and

play back last received IR signal

at button press. IR frames of known protocols are sent by the approriate protocol encoder.

UNKNOWN

protocol frames are stored as raw data and sent with

sendRaw()

.

ReceiveAndSendDistanceWidth

Try to decode each IR frame with the universal

DistanceWidth decoder

, store the data and send it on button press with

sendPulseDistanceWidthFromArray()

.
Storing data for distance width protocol requires 17 bytes.
The ReceiveAndSend example requires 16 bytes for known protocol data and 37 bytes for raw data of e.g.NEC protocol.

ReceiveOneAndSendMultiple

Serves as a IR

remote macro expander

. Receives Samsung32 protocol and on receiving a specified input frame, it sends multiple Samsung32 frames with appropriate delays in between.
This serves as a

Netflix-key emulation

for my old Samsung H5273 TV.

IRDispatcherDemo

Framework for

calling different functions of your program

for different IR codes.

IRrelay


Control a relay

(connected to an output pin) with your remote.

IRremoteExtensionTest


Example

for a user defined class, which itself uses the IRrecv class from IRremote.

SendLGAirConditionerDemo


Example

for sending LG air conditioner IR codes controlled by Serial input.
By just using the function

bool Aircondition_LG::sendCommandAndParameter(char aCommand, int aParameter)

you can control the air conditioner by any other command source.
The file acLG.h contains the command documentation of the LG air conditioner IR protocol. Based on reverse engineering of the LG AKB73315611 remote.

IReceiverTimingAnalysis can be tested online with

WOKWI

Click on the receiver while simulation is running to specify individual IR codes.

ReceiverTimingAnalysis

This

example

analyzes the signal delivered by your IR receiver module.
Values can be used to determine the stability of the received signal as well as a hint for determining the protocol.
It also computes the

MARK_EXCESS_MICROS

value, which is the extension of the mark (pulse) duration introduced by the IR receiver module.
It can be tested online with

WOKWI

.
Click on the receiver while simulation is running to specify individual NEC IR codes.

UnitTest

ReceiveDemo + SendDemo in one program. Demonstrates

receiving while sending

.
Here you see the delay of the receiver output (blue) from the IR diode input (yellow).

WOKWI online examples

Issues and discussions

  • Do not open an issue without first testing some of the examples!
  • If you have a problem, please post the MCVE (Minimal Complete Verifiable Example) showing this problem. My experience is, that most of the times you will find the problem while creating this MCVE 😄.

  • Use code blocks

    ;

    it helps us help you when we can read your code!

Compile options / macros for this library

To customize the library to different requirements, there are some compile options / macros available.
These macros must be defined in your program

before

the line

#include

to take effect.
Modify them by enabling / disabling them, or change the values if applicable.

Name
Default value
Description

RAW_BUFFER_LENGTH

100
Buffer size of raw input buffer. Must be even! 100 is sufficient for regular protocols of up to 48 bits, but for most air conditioner protocols a value of up to 750 is required. Use the ReceiveDump example to find smallest value for your requirements.

EXCLUDE_UNIVERSAL_PROTOCOLS

disabled
Excludes the universal decoder for pulse distance protocols and decodeHash (special decoder for all protocols) from

decode()

. Saves up to 1000 bytes program memory.

DECODE_

all
Selection of individual protocol(s) to be decoded. You can specify multiple protocols. See

here


DECODE_STRICT_CHECKS

disabled
Check for additional required characteristics of protocol timing like length of mark for a constant mark protocol, where space length determines the bit value. Requires up to 194 additional bytes of program memory.

IR_REMOTE_DISABLE_RECEIVE_COMPLETE_CALLBACK

disabled
Saves up to 60 bytes of program memory and 2 bytes RAM.

MARK_EXCESS_MICROS

20
MARK_EXCESS_MICROS is subtracted from all marks and added to all spaces before decoding, to compensate for the signal forming of different IR receiver modules.

RECORD_GAP_MICROS

5000
Minimum gap between IR transmissions, to detect the end of a protocol.Must be greater than any space of a protocol e.g. the NEC header space of 4500 µs.Must be smaller than any gap between a command and a repeat; e.g. the retransmission gap for Sony is around 24 ms.Keep in mind, that this is the delay between the end of the received command and the start of decoding.

IR_INPUT_IS_ACTIVE_HIGH

disabled
Enable it if you use a RF receiver, which has an active HIGH output signal.

IR_SEND_PIN

disabled
If specified, it reduces program size and improves send timing for AVR. If you want to use a variable to specify send pin e.g. with

setSendPin(uint8_t aSendPinNumber)

, you must not use / disable this macro in your source.

SEND_PWM_BY_TIMER

disabled
Disables carrier PWM generation in software and use hardware PWM (by timer). Has the advantage of more exact PWM generation, especially the duty cycle (which is not very relevant for most IR receiver circuits), and the disadvantage of using a hardware timer, which in turn is not available for other libraries and to fix the send pin (but not the receive pin) at the

dedicated timer output pin(s)

. Is enabled for ESP32 and RP2040 in all examples, since they support PWM gereration for each pin without using a shared resource (timer).

USE_NO_SEND_PWM

disabled
Uses no carrier PWM, just simulate an

active low

receiver signal. Used for transferring signal by cable instead of IR. Overrides

SEND_PWM_BY_TIMER

definition.

IR_SEND_DUTY_CYCLE_PERCENT

30
Duty cycle of IR send signal.

USE_OPEN_DRAIN_OUTPUT_FOR_SEND_PIN

disabled
Uses or simulates open drain output mode at send pin.

Attention, active state of open drain is LOW

, so connect the send LED between positive supply and send pin!

DISABLE_CODE_FOR_RECEIVER

disabled
Saves up to 450 bytes program memory and 269 bytes RAM if receiving functionality is not required.

EXCLUDE_EXOTIC_PROTOCOLS

disabled
Excludes BANG_OLUFSEN, BOSEWAVE, WHYNTER, FAST and LEGO_PF from

decode()

and from sending with

IrSender.write()

. Saves up to 650 bytes program memory.

FEEDBACK_LED_IS_ACTIVE_LOW

disabled
Required on some boards (like my BluePill and my ESP8266 board), where the feedback LED is active low.

NO_LED_FEEDBACK_CODE

disabled
Disables the LED feedback code for send and receive. Saves around 100 bytes program memory for receiving, around 500 bytes for sending and halving the receiver ISR (Interrupt Service Routine) processing time.

MICROS_PER_TICK

50
Resolution of the raw input buffer data. Corresponds to 2 pulses of each 26.3 µs at 38 kHz.

TOLERANCE_FOR_DECODERS_MARK_OR_SPACE_MATCHING

25
Relative tolerance (in percent) for matchTicks(), matchMark() and matchSpace() functions used for protocol decoding.

DEBUG

disabled
Enables lots of lovely debug output.

IR_USE_AVR_TIMER*

Selection of timer to be used for generating IR receiving sample interval.

These next macros for

TinyIRReceiver

must be defined in your program before the line

#include

to take effect.

Name
Default value
Description

IR_RECEIVE_PIN

2
The pin number for TinyIRReceiver IR input, which gets compiled in.

IR_FEEDBACK_LED_PIN


LED_BUILTIN

The pin number for TinyIRReceiver feedback LED, which gets compiled in.

NO_LED_FEEDBACK_CODE

disabled
Disables the feedback LED function. Saves 14 bytes program memory.

DISABLE_PARITY_CHECKS

disabled
Disables the addres and command parity checks. Saves 48 bytes program memory.

USE_EXTENDED_NEC_PROTOCOL

disabled
Like NEC, but take the 16 bit address as one 16 bit value and not as 8 bit normal and 8 bit inverted value.

USE_ONKYO_PROTOCOL

disabled
Like NEC, but take the 16 bit address and command each as one 16 bit value and not as 8 bit normal and 8 bit inverted value.

USE_FAST_PROTOCOL

disabled
Use FAST protocol (no address and 16 bit data, interpreted as 8 bit command and 8 bit inverted command) instead of NEC.

ENABLE_NEC2_REPEATS

disabled
Instead of sending / receiving the NEC special repeat code, send / receive the original frame for repeat.

USE_CALLBACK_FOR_TINY_RECEIVER

disabled
Call the fixed function

void handleReceivedTinyIRData()

each time a frame or repeat is received.

The next macro for

IRCommandDispatcher

must be defined in your program before the line

#include

to take effect.
|

USE_TINY_IR_RECEIVER

| disabled | Use

TinyReceiver

for receiving IR codes. |
|

IR_COMMAND_HAS_MORE_THAN_8_BIT

| disabled | Enables mapping and dispatching of IR commands consisting of more than 8 bits. Saves up to 160 bytes program memory and 4 bytes RAM + 1 byte RAM per mapping entry. |
|

BUZZER_PIN

| | If

USE_TINY_IR_RECEIVER

is enabled, the pin to be used for the optional 50 ms buzzer feedback before executing a command. Other IR libraries than Tiny are not compatible with tone() command. |

Changing include (*.h) files with Arduino IDE

First, use Sketch > Show Sketch Folder (Ctrl+K).
If you have not yet saved the example as your own sketch, then you are instantly in the right library folder.
Otherwise you have to navigate to the parallel

libraries

folder and select the library you want to access.
In both cases the library source and include files are located in the libraries

src

directory.
The modification must be renewed for each new library version!

Modifying compile options / macros with PlatformIO

If you are using PlatformIO, you can define the macros in the

platformio.ini

file with

build_flags = -D MACRO_NAME

or

build_flags = -D MACRO_NAME=macroValue

.

Modifying compile options / macros with Sloeber IDE

If you are using

Sloeber

as your IDE, you can easily define global symbols with Properties > Arduino > CompileOptions.

Supported Boards


Issues and discussions with the content “Is it possible to use this library with the ATTinyXYZ? / board XYZ” without any reasonable explanations will be immediately closed without further notice.

Digispark boards are only tested with

ATTinyCore

using

New Style

pin mapping for the Digispark Pro board.
ATtiny boards are only tested with

ATTinyCore

or

megaTinyCore

.

  • Arduino Uno / Mega / Leonardo / Duemilanove / Diecimila / LilyPad / Mini / Fio / Nano etc.
  • Arduino Uno R4, but not yet tested, because of lack of a R4 board.

    Sending does not work

    on the

    arduino:renesas_uno:unor4wifi

    .
  • Teensy 1.0 / 1.0++ / 2.0 / 2++ / 3.0 / 3.1 / 3.2 / Teensy-LC – but

    limited support

    ; Credits: PaulStoffregen (Teensy Team)
  • Sanguino
  • ATmega8, 48, 88, 168, 328
  • ATmega8535, 16, 32, 164, 324, 644, 1284,
  • ATmega64, 128
  • ATmega4809 (Nano every)
  • ATtiny3217 (Tiny Core 32 Dev Board)
  • ATtiny84, 85, 167 (Digispark + Digispark Pro)
  • SAMD21 (Zero, MKR*,

    but not SAMD51 and not DUE, the latter is SAM architecture

    )
  • ESP8266
  • ESP32 (ESP32-C3 since board package 2.0.2 from Espressif)

    not for ESP32 core version > 3.0.0
  • Sparkfun Pro Micro
  • Nano Every, Uno WiFi Rev2, nRF5 BBC MicroBit, Nano33_BLE
  • BluePill with STM32
  • RP2040 based boards (Raspberry Pi Pico, Nano RP2040 Connect etc.)

For ESP8266/ESP32,

this library

supports an

impressive set of protocols and a lot of air conditioners

We are open to suggestions for adding support to new boards, however we highly recommend you contact your supplier first and ask them to provide support from their side.
If you can provide

examples of using a periodic timer for interrupts

for the new board, and the board name for selection in the Arduino IDE, then you have way better chances to get your board supported by IRremote.

Timer and pin usage

The

receiver sample interval of 50 µs is generated by a timer

. On many boards this must be a hardware timer. On some boards where a software timer is available, the software timer is used.

Every pin can be used for receiving.
If software PWM is selected, which is default, every pin can also be used for sending. Sending with software PWM does not require a timer!

The TinyReceiver example uses the

TinyReceiver

library, which can

only receive NEC codes, but does not require any timer

and runs even on a 1 MHz ATtiny85.

The code for the timer and the

timer selection

is located in

private/IRTimer.hpp

. The selected timer can be adjusted here.


Be aware that the hardware timer used for receiving should not be used for analogWrite()!

.

No timer required for sending

The

send PWM signal

is by default generated by software.

Therefore every pin can be used for sending

.
The PWM pulse length is guaranteed to be constant by using

delayMicroseconds()

.
Take care not to generate interrupts during sending with software generated PWM, otherwise you will get jitter in the generated PWM.
E.g. wait for a former

Serial.print()

statement to be finished by

Serial.flush()

.
Since the Arduino

micros()

function has a resolution of 4 µs at 16 MHz, we always see a small jitter in the signal, which seems to be OK for the receivers.

Software generated PWM showing small jitter because of the limited resolution of 4 µs of the Arduino core

micros()

function for an ATmega328
Detail (ATmega328 generated) showing 30% duty cycle

Disclaimer


This library was designed to fit inside MCUs with relatively low levels of resources and was intended to work as a library together with other applications which also require some resources of the MCU to operate.

For

air conditioners


see this fork

, which supports an impressive set of protocols and a lot of air conditioners.

For

long signals

see the blog entry:

“Recording long Infrared Remote control signals with Arduino”

.

If you get something like this:

PULSE_DISTANCE: HeaderMarkMicros=8900 HeaderSpaceMicros=4450 MarkMicros=550 OneSpaceMicros=1700 ZeroSpaceMicros=600  NumberOfBits=56 0x43D8613C 0x3BC3BC

then you have a code consisting of

56 bits

, which is probably from an air conditioner remote.
You can send it with sendPulseDistance().

uint32_t

tRawData[] = {

0xB02002

,

0xA010

}; IrSender.sendPulseDistance(

38

,

3450

,

1700

,

450

,

1250

,

450

,

400

, &tRawData[],

48

,

false

, , );

You can send it with calling sendPulseDistanceWidthData() twice, once for the first 32 bit and next for the remaining 24 bits.

The PulseDistance or PulseWidth decoders just decode a timing steam to a bit stream

.
They can not put any semantics like address, command or checksum on this bitstream, since it is no known protocol.
But the bitstream is way more readable, than a timing stream. This bitstream is read

LSB first by default

.
If this does not suit you for further research, you can change it

here

.

If you see something like

Protocol=UNKNOWN Hash=0x13BD886C 35 bits received

as output of e.g. the ReceiveDemo example, you either have a problem with decoding a protocol, or an unsupported protocol.

  • If you have an

    odd number of bits

    received, your receiver circuit probably has problems. Maybe because the IR signal is too weak.
  • If you see timings like

    + 600,- 600 + 550,- 150 + 200,- 100 + 750,- 550

    then one 450 µs space was split into two 150 and 100 µs spaces with a spike / error signal of 200 µs between. Maybe because of a defective receiver or a weak signal in conjunction with another light emitting source nearby.
  • If you see timings like

    + 500,- 550 + 450,- 550 + 500,- 500 + 500,-1550

    , then marks are generally shorter than spaces and therefore

    MARK_EXCESS_MICROS

    (specified in your ino file) should be

    negative

    to compensate for this at decoding.
  • If you see

    Protocol=UNKNOWN Hash=0x0 1 bits received

    it may be that the space after the initial mark is longer than


    RECORD_GAP_MICROS


    .
    This was observed for some LG air conditioner protocols. Try again with a line e.g.

    #define RECORD_GAP_MICROS 12000

    before the line

    #include

    in your .ino file.
  • To see more info supporting you to find the reason for your UNKNOWN protocol, you must enable the line

    //#define DEBUG

    in IRremoteInt.h.
Control LED's with an IR Remote in Tinkercad Circuits! #arduino
Control LED’s with an IR Remote in Tinkercad Circuits! #arduino

How To Program For IR Remote Controller

  • Include the library:
  • Declare a DIYables_IRcontroller_17 or DIYables_IRcontroller_21 object corresponds with 17-key or 21-key IR remote controllers:
  • Initialize the IR Controller.
  • In the loop, check if a key is pressed or not. If yes, get the key
  • Once you have detected a key press, you can perform specific actions based on each key.

How to Connect an IR Receiver to the Arduino

There are several different types of IR receivers, some are stand-alone, and some are mounted on a breakout board. Check the datasheet for your particular IR receiver since the pins might be arranged differently than the HX1838 IR receiver and remote set I am using here. However, all IR receivers will have three pins: signal, ground, and Vcc.

Lets get started with the hardware connections. The pin layout on most breakout boards looks like this:

The pinout of most stand-alone diodes is like this:

To connect a breakout board mounted IR receiver, hook it up to the Arduino like this:

To connect a stand-alone receiver diode, wire it like this:

How to use any Infrared remote with Arduino
How to use any Infrared remote with Arduino

decodedIRData structure

struct

IRData

{

decode_type_t

protocol;

//

UNKNOWN, NEC, SONY, RC5, PULSE_DISTANCE, ...

uint16_t

address;

//

Decoded address

uint16_t

command;

//

Decoded command

uint16_t

extra;

//

Used for Kaseikyo unknown vendor ID. Ticks used for decoding Distance protocol.

uint16_t

numberOfBits;

//

Number of bits received for data (address + command + parity) - to determine protocol length if different length are possible.

uint8_t

flags;

//

IRDATA_FLAGS_IS_REPEAT, IRDATA_FLAGS_WAS_OVERFLOW etc. See IRDATA_FLAGS_* definitions

IRRawDataType decodedRawData;

//

Up to 32 (64 bit for 32 bit CPU architectures) bit decoded raw data, used for sendRaw functions.

uint32_t

decodedRawDataArray[RAW_DATA_ARRAY_SIZE];

//

32 bit decoded raw data, to be used for send function.

irparams_struct *rawDataPtr;

//

Pointer of the raw timing data to be decoded. Mainly the data buffer filled by receiving ISR.

};
Flags

This is the

list of flags

contained in the flags field.
Check it with e.g.

if(IrReceiver.decodedIRData.flags & IRDATA_FLAGS_IS_REPEAT)

.

Flag name
Description

IRDATA_FLAGS_IS_REPEAT
The gap between the preceding frame is as smaller than the maximum gap expected for a repeat. !!!We do not check for changed command or address, because it is almost not possible to press 2 different buttons on the remote within around 100 ms!!!

IRDATA_FLAGS_IS_AUTO_REPEAT
The current repeat frame is a repeat, that is always sent after a regular frame and cannot be avoided. Only specified for protocols DENON, and LEGO.

IRDATA_FLAGS_PARITY_FAILED
The current (autorepeat) frame violated parity check.

IRDATA_FLAGS_TOGGLE_BIT
Is set if RC5 or RC6 toggle bit is set.

IRDATA_FLAGS_EXTRA_INFO
There is extra info not contained in address and data (e.g. Kaseikyo unknown vendor ID, or in decodedRawDataArray).

IRDATA_FLAGS_WAS_OVERFLOW
irparams.rawlen is set to 0 in this case to avoid endless OverflowFlag.

IRDATA_FLAGS_IS_MSB_FIRST
This value is mainly determined by the (known) protocol.

To access the RAW data, use:

auto

myRawdata= IrReceiver.decodedIRData.decodedRawData;

The definitions for the

IrReceiver.decodedIRData.flags

are described

here

.

Print all fields:
IrReceiver.printIRResultShort(&Serial);
Print the raw timing data received:
IrReceiver.printIRResultRawFormatted(&Serial, 

true

);`

The raw data depends on the internal state of the Arduino timer in relation to the received signal and might therefore be slightly different each time. (resolution problem). The decoded values are the interpreted ones which are tolerant to such slight differences!

Print how to send the received data:
IrReceiver.printIRSendUsage(&Serial);

Conclusion – Arduino IR remote controller

In this tutorial you have seen how to integrate an IR remote controller to make your application more dynamic.

To recap:

  • First build the circuit with an IR receiver. One of the pins contains the data, which you are going to connect to a digital pin on your Arduino board.
  • Then, you need to map each button so you can know on what you’ve pressed in your code. To map the buttons, first upload a program to print the numbers you get. Create some defines to map those numbers to existing buttons – you will need to repeat this step for each new remote controller you use.
  • Remove the printing number code, and write your application using the defines. In the void loop() function, you can use a switch structure to do a different action for each button.

Overview

Supported IR Protocols


NEC / Onkyo / Apple


Denon / Sharp


Panasonic / Kaseikyo


JVC


LG


RC5


RC6


Samsung


Sony


Universal Pulse Distance


Universal Pulse Width


Hash


Pronto


BoseWave


Bang & Olufsen


Lego


FAST


Whynter


MagiQuest

Protocols can be switched off and on by defining macros before the line

#include

like

here

:

#

define

DECODE_NEC

//

#define DECODE_DENON

#include

Features

  • Lots of tutorials and examples.
  • Actively maintained.
  • Allows receiving and sending of

    raw timing data

    .
Arduino Controlled using TV or IR Remote
Arduino Controlled using TV or IR Remote

Wiring Diagram

Wiring diagram between Arduino and IR Receiver Module

This image is created using Fritzing. Click to enlarge image

The real wiring diagram

Wiring diagram between Arduino and IR Receiver Sensor

This image is created using Fritzing. Click to enlarge image

The real wiring diagram

Wiring diagram between Arduino and IR Receiver Sensor and Adapter

You can also connect The IR receiver sensor to the adapter before connecting to the Arduino.

How IR Remotes and Receivers Work

A typical infrared communication system requires an IR transmitter and an IR receiver. The transmitter looks just like a standard LED, except it produces light in the IR spectrum instead of the visible spectrum. If you have a look at the front of a TV remote, you’ll see the IR transmitter LED:

The same type of LED is used in IR transmitter breakout boards for the Arduino. You can see it at the front of this Keyes IR transmitter:

The IR receiver is a photodiode and pre-amplifier that converts the IR light into an electrical signal. IR receiver diodes typically look like this:

Some may come on a breakout board like this:

IR Signal Modulation

IR light is emitted by the sun, light bulbs, and anything else that produces heat. That means there is a lot of IR light noise all around us. To prevent this noise from interfering with the IR signal, a signal modulation technique is used.

In IR signal modulation, an encoder on the IR remote converts a binary signal into a modulated electrical signal. This electrical signal is sent to the transmitting LED. The transmitting LED converts the modulated electrical signal into a modulated IR light signal. The IR receiver then demodulates the IR light signal and converts it back to binary before passing on the information to a microcontroller:

The modulated IR signal is a series of IR light pulses switched on and off at a high frequency known as the carrier frequency. The carrier frequency used by most transmitters is 38 kHz, because it is rare in nature and thus can be distinguished from ambient noise. This way the IR receiver will know that the 38 kHz signal was sent from the transmitter and not picked up from the surrounding environment.

The receiver diode detects all frequencies of IR light, but it has a band-pass filter and only lets through IR at 38 kHz. It then amplifies the modulated signal with a pre-amplifier and converts it to a binary signal before sending it to a microcontroller.

IR Transmission Protocols

The pattern in which the modulated IR signal is converted to binary is defined by a transmission protocol. There are many IR transmission protocols. Sony, Matsushita, NEC, and RC5 are some of the more common protocols.

The NEC protocol is also the most common type in Arduino projects, so I’ll use it as an example to show you how the receiver converts the modulated IR signal to a binary one.

Logical ‘1’ starts with a 562.5 µs long HIGH pulse of 38 kHz IR followed by a 1,687.5 µs long LOW pulse. Logical ‘0’ is transmitted with a 562.5 µs long HIGH pulse followed by a 562.5 µs long LOW pulse:

This is how the NEC protocol encodes and decodes the binary data into a modulated signal. Other protocols differ only in the duration of the individual HIGH and LOW pulses.

IR Codes

Each time you press a button on the remote control, a unique hexadecimal code is generated. This is the information that is modulated and sent over IR to the receiver. In order to decipher which key is pressed, the receiving microcontroller needs to know which code corresponds to each key on the remote.

Different remotes send different codes for the keypresses, so you’ll need to determine the code generated for each key on your particular remote. If you can find the datasheet, the IR key codes should be listed. If not though, there is a simple Arduino sketch that will read most of the popular remote controls and print the hexadecimal codes to the serial monitor when you press a key. I’ll show you how to set that up in a minute, but first we need to connect the receiver to the Arduino…

How to make Universal Remote Controller for all Devices
How to make Universal Remote Controller for all Devices

Install an Arduino library for the IR remote controller

Be reassured: you won’t have to write hundreds of lines of code to be able to decode the data you get from the IR receiver. Someone already did that for you. All you need to do is to install an Arduino library and use it.

To do that, open the Arduino IDE. Go to Tools > Manage Libraries.

You will get a new window, where you will see many available libraries that you can install. In the search bar, type “irremote”.

You will find this IRremote library (by shirrif, z3t0, ArminJo).

Select the latest version (whatever version is fine, it doesn’t have to be exactly the same as the one you see on the screenshot). The important thing is to have a version starting by at least 3. Don’t use version 2.

Click on “Install” and wait a few seconds. Then you can close the window, and restart the Arduino IDE.

The IRremote library is now installed and ready to be used!

(if you want to download a specific library version not available from the Arduino IDE, you can also directly get the library from GitHub)

Minimal CPU clock frequency

For receiving, the

minimal CPU clock frequency is 4 MHz

, since the 50 µs timer ISR (Interrupt Service Routine) takes around 12 µs on a 16 MHz ATmega.
The TinyReceiver, which reqires no polling, runs with 1 MHz.
For sending, the

default software generated PWM has problems on AVR running with 8 MHz

. The PWM frequency is around 30 instead of 38 kHz and RC6 is not reliable. You can switch to timer PWM generation by

#define SEND_PWM_BY_TIMER

.

How to Hack any IR Remote using arduino
How to Hack any IR Remote using arduino

What is Infrared?

Infrared radiation is a form of light similar to the light we see all around us. The only difference between IR light and visible light is the frequency and wavelength. Infrared radiation lies outside the range of visible light, so humans can’t see it:

Because IR is a type of light, IR communication requires a direct line of sight from the receiver to the transmitter. It can’t transmit through walls or other materials like WiFi or Bluetooth.

Ambiguous protocols

NEC, Extended NEC, ONKYO

The

NEC protocol

is defined as 8 bit address and 8 bit command. But the physical address and data fields are each 16 bit wide.
The additional 8 bits are used to send the inverted address or command for parity checking.
The

extended NEC protocol

uses the additional 8 parity bit of address for a 16 bit address, thus disabling the parity check for address.
The

ONKYO protocol

in turn uses the additional 8 parity bit of address and command for a 16 bit address and command.

The decoder reduces the 16 bit values to 8 bit ones if the parity is correct.
If the parity is not correct, it assumes no parity error, but takes the values as 16 bit values without parity assuming extended NEC or extended NEC protocol protocol.

But now we have a problem when we want to receive e.g. the

16 bit

address 0x00FF or 0x32CD!
The decoder interprets this as a NEC 8 bit address 0x00 / 0x32 with correct parity of 0xFF / 0xCD and reduces it to 0x00 / 0x32.

One way to handle this, is to force the library to

always

use the ONKYO protocol interpretation by using

#define DECODE_ONKYO

.
Another way is to check if

IrReceiver.decodedIRData.protocol

is NEC and not ONKYO and to revert the parity reducing manually.

NEC, NEC2

On a long press, the

NEC protocol

does not repeat its frame, it sends a special short repeat frame.
This enables an easy distinction between long presses and repeated presses and saves a bit of battery energy.
This behavior is quite unique for NEC and its derived protocols like LG.

So there are of course also remote control systems, which uses the NEC protocol but on a long press just repeat the first frame instead of sending the special short repeat frame. We named this the

NEC2

protocol and it is sent with

sendNEC2()

.
But be careful, the NEC2 protocol can only be detected by the NEC library decoder

after

the first frame and if you do a long press!

HOW TO MAKE AN ARDUINO CAR USING IR REMOTE | THE CODE IS EPIC!!
HOW TO MAKE AN ARDUINO CAR USING IR REMOTE | THE CODE IS EPIC!!

Code

#include

int RECV_PIN = 11; int ledPin = 10; boolean ledState = LOW; IRrecv irrecv(RECV_PIN); decode_results results; void setup(){ Serial.begin(9600); irrecv.enableIRIn(); pinMode(ledPin,OUTPUT); } void loop() { if (irrecv.decode(&results)) { Serial.println(results.value, HEX); if(results.value == 0xFD00FF){ ledState = !ledState; digitalWrite(ledPin,ledState); } irrecv.resume(); } }

Giải thích code

Đầu tiên kiểm tra xem remote đã nhận tín hiệu chưa nếu quá trình nhận tín hiệu thành công thì xuất ra màn hình giá trị mã HEX.

if (irrecv.decode(&results)) … if(results.value == 0xFD00FF)

Đảo trạng thái của LED

ledState = !ledState; digitalWrite(ledPin,ledState);

Nhận giá trị tiếp theo.

irrecv.resume();

Thư viện

Cài đặt thư viện IR Remote: Tải ngay

Why do we use 30% duty cycle for sending

We

do it

according to the statement in the

Vishay datasheet

:

  • Carrier duty cycle 50 %, peak current of emitter IF = 200 mA, the resulting transmission distance is 25 m.
  • Carrier duty cycle 10 %, peak current of emitter IF = 800 mA, the resulting transmission distance is 29 m. – Factor 1.16
    The reason is, that it is not the pure energy of the fundamental which is responsible for the receiver to detect a signal.
    Due to automatic gain control and other bias effects, high intensity of the 38 kHz pulse counts more than medium intensity (e.g. 50% duty cycle) at the same total energy.

How we decode signals

The IR signal is sampled at a

50 µs interval

. For a constant 525 µs pulse or pause we therefore get 10 or 11 samples, each with 50% probability.
And believe me, if you send a 525 µs signal, your receiver will output something between around 400 and 700 µs!
Therefore

we decode by default with a +/- 25% margin

using the formulas

here

.
E.g. for the NEC protocol with its 560 µs unit length, we have TICKS_LOW = 8.358 and TICKS_HIGH = 15.0. This means, we accept any value between 8 ticks / 400 µs and 15 ticks / 750 µs (inclusive) as a mark or as a zero space. For a one space we have TICKS_LOW = 25.07 and TICKS_HIGH = 45.0.
And since the receivers generated marks are longer or shorter than the spaces,
we have introduced the


MARK_EXCESS_MICROS


macro
to compensate for this receiver (and signal strength as well as ambient light dependent 😞 ) specific deviation.
Welcome to the world of

real world signal processing

.

NEC encoding diagrams

Created with sigrok PulseView with IR_NEC decoder by DjordjeMandic.
8 bit address NEC code

16 bit address NEC code

Quick comparison of 5 Arduino IR receiving libraries


This is a short comparison and may not be complete or correct.

I created this comparison matrix for

myself

in order to choose a small IR lib for my project and to have a quick overview, when to choose which library.
It is dated from

24.06.2022

and updated 10/2023. If you have complains about the data or request for extensions, please send a PM or open a discussion.


Here

you find an

ESP8266/ESP32

version of IRremote with an


impressive list of supported protocols


.

Subject

IRMP


IRLremote


IRLib2


mostly unmaintained


IRremote


TinyIR


IRsmallDecoder

Number of protocols

50

Nec + Panasonic + Hash *
12 + Hash *
17 + PulseDistance + Hash *
NEC + FAST
NEC + RC5 + Sony + Samsung

Timing method receive
Timer2 or interrupt for pin 2 or 3

Interrupt

Timer2 or interrupt for pin 2 or 3
Timer2

Interrupt


Interrupt

Timing method send
PWM and timing with Timer2 interrupts
Timer2 interrupts
Timer2 and blocking wait
PWM with Timer2 and/or blocking wait with delayMicroseconds()
blocking wait with delayMicroseconds()
%

Send pins
All
All
All ?
Timer dependent
All
%

Decode method
OnTheFly
OnTheFly
RAM
RAM
OnTheFly
OnTheFly

Encode method
OnTheFly
OnTheFly
OnTheFly
OnTheFly or RAM
OnTheFly
%

Callback support
x
%
%
x
x
%

Repeat handling
Receive + Send (partially)
%
?
Receive + Send
Receive + Send
Receive

LED feedback
x
%
x
x
Receive
%

FLASH usage (simple NEC example with 5 prints)
1820(4300 for 15 main / 8000 for all 40 protocols)(+200 for callback)(+80 for interrupt at pin 2+3)
1270(1400 for pin 2+3)
4830
1770

900

?1100?

RAM usage
52(73 / 100 for 15 (main) / 40 protocols)
62
334
227

19

29

Supported platforms

avr, megaavr, attiny, Digispark (Pro), esp8266, ESP32, STM32, SAMD 21, Apollo3(plus arm and pic for non Arduino IDE)

avr, esp8266
avr, SAMD 21, SAMD 51
avr, attiny,

esp8266

, esp32, SAM, SAMD

All platforms with attachInterrupt()


All platforms with attachInterrupt()

Last library update
5/2023
4/2018
11/2022
9/2023
5/2023
2/2022

Remarks
Decodes 40 protocols concurrently.39 Protocols to send.Work in progress.
Only one protocol at a time.
Consists of 5 libraries. *Project containing bugs – 63 issues, 10 pull requests.
Universal decoder and encoder.Supports

Pronto

codes and sending of raw timing values.
Requires no timer.
Requires no timer.

* The Hash protocol gives you a hash as code, which may be sufficient to distinguish your keys on the remote, but may not work with some protocols like Mitsubishi

Useful links

License

Up to the version 2.7.0, the License is GPLv2.
From the version 2.8.0, the license is the MIT license.

Copyright

Initially coded 2009 Ken Shirriff

http://www.righto.com

Copyright (c) 2016-2017 Rafi Khan
Copyright (c) 2020-2023

Armin Joachimsmeyer




Arduino – IR Remote Control

You’ve likely encountered the infrared remote controller, also known as the IR remote controller, while using home electronic devices like TVs and air conditioners… In this tutorial, we are going to learn how to use infrared (IR) remote controller and infrared receiver to control Arduino. In detail, we will learn:

  • How to connect an IR receiver to Arduino board
  • How to program Arduino to read the command from IR remote controller via IR receiver

Then you can modify the code to control LED, fan, pump, actuator… via IR remote controller.

Arduino IR Remote Control Relay Module
Arduino IR Remote Control Relay Module

Map each button to a number

Now we need to map each button to a number, and save that into our program, so we can recognize which button was actually pressed.

Because with just the previous code, well, what does “12” means? In my specific case, “12” means that I pressed on the button “1” of the remote controller.

Here I’m going to show you the step by step process to map each button you want to use, to an actual number in your code.

Important note: each remote controller will produce different numbers. I got “12” for button “1” but you’re probably going to have something different for each controller you try.

Watch this video as an additional resource to this tutorial (steps 1-2-3 for mapping buttons):

After watching the video, subscribe to the Robotics Back-End Youtube channel so you don’t miss the next tutorials!

Step 1: Setup – Print number for the buttons you want

Let’s use the same code we wrote just before.

Run the code on your Arduino and open the Serial Monitor.

For each button you want to use in your application, press the button and write down the number you get.

In my case, here is what I get:

  • 12: button 1
  • 24: button 2
  • 94: button 3
  • 64: button play/pause

Etc etc. Do this for each button you need. And once again, you will certainly have different values than me.

Step 2: Add the numbers into your program

Once you know what are the numbers for each button you’re going to use, add some defines at the top of your program.

#include

#define IR_RECEIVE_PIN 8 #define IR_BUTTON_1 12 #define IR_BUTTON_2 24 #define IR_BUTTON_3 94 #define IR_BUTTON_PLAY_PAUSE 64 …

Now, you don’t need to worry about the numbers anymore, you can just use IR_BUTTON_1 when you want to use button 1.

Step 3: Write your application program

After you’ve done the setup, you don’t need to print the number every time on the Serial monitor. You can remove the unneeded lines and write your application, using for example a switch structure.

#include

#define IR_RECEIVE_PIN 8 #define IR_BUTTON_1 12 #define IR_BUTTON_2 24 #define IR_BUTTON_3 94 #define IR_BUTTON_PLAY_PAUSE 64 void setup() { Serial.begin(9600); IrReceiver.begin(IR_RECEIVE_PIN); } void loop() { if (IrReceiver.decode()) { IrReceiver.resume(); int command = IrReceiver.decodedIRData.command; switch (command) { case IR_BUTTON_1: { Serial.println(“Pressed on button 1”); break; } case IR_BUTTON_2: { Serial.println(“Pressed on button 2”); break; } case IR_BUTTON_3: { Serial.println(“Pressed on button 3”); break; } case IR_BUTTON_PLAY_PAUSE: { Serial.println(“Pressed on button play/pause”); break; } default: { Serial.println(“Button not recognized”); } } } }

As you can see, for each button we have mapped, we add one more block of code in the switch.

When you press on a button, the IR receiver will send the corresponding number to the Arduino. Then in your code, you get the data with IrReceiver.decodedIRData.command. And then, in the switch, depending on which value you have, you will execute a different action.

If you run the code and press on some buttons, you’ll get something like this in the Serial Monitor.

Pressed on button 1 Pressed on button 2 Pressed on button 3 Pressed on button 3 Button not recognized Pressed on button play/pause

Now, you can use this code structure as a template for any project you do with an IR remote controller. Just remember to repeat steps 1 and 2 for each new controller you use, because you’re going to have different numbers for the buttons.

You can also decide to use an “if/else if/else” structure instead of the switch. This will work the same, but it’s maybe a bit cleaner with the switch.

Disclaimer


This library was designed to fit inside MCUs with relatively low levels of resources and was intended to work as a library together with other applications which also require some resources of the MCU to operate.

For

air conditioners


see this fork

, which supports an impressive set of protocols and a lot of air conditioners.

For

long signals

see the blog entry:

“Recording long Infrared Remote control signals with Arduino”

.

If you get something like this:

PULSE_DISTANCE: HeaderMarkMicros=8900 HeaderSpaceMicros=4450 MarkMicros=550 OneSpaceMicros=1700 ZeroSpaceMicros=600  NumberOfBits=56 0x43D8613C 0x3BC3BC

then you have a code consisting of

56 bits

, which is probably from an air conditioner remote.
You can send it with sendPulseDistance().

uint32_t

tRawData[] = {

0xB02002

,

0xA010

}; IrSender.sendPulseDistance(

38

,

3450

,

1700

,

450

,

1250

,

450

,

400

, &tRawData[],

48

,

false

, , );

You can send it with calling sendPulseDistanceWidthData() twice, once for the first 32 bit and next for the remaining 24 bits.

The PulseDistance or PulseWidth decoders just decode a timing steam to a bit stream

.
They can not put any semantics like address, command or checksum on this bitstream, since it is no known protocol.
But the bitstream is way more readable, than a timing stream. This bitstream is read

LSB first by default

.
If this does not suit you for further research, you can change it

here

.

If you see something like

Protocol=UNKNOWN Hash=0x13BD886C 35 bits received

as output of e.g. the ReceiveDemo example, you either have a problem with decoding a protocol, or an unsupported protocol.

  • If you have an

    odd number of bits

    received, your receiver circuit probably has problems. Maybe because the IR signal is too weak.
  • If you see timings like

    + 600,- 600 + 550,- 150 + 200,- 100 + 750,- 550

    then one 450 µs space was split into two 150 and 100 µs spaces with a spike / error signal of 200 µs between. Maybe because of a defective receiver or a weak signal in conjunction with another light emitting source nearby.
  • If you see timings like

    + 500,- 550 + 450,- 550 + 500,- 500 + 500,-1550

    , then marks are generally shorter than spaces and therefore

    MARK_EXCESS_MICROS

    (specified in your ino file) should be

    negative

    to compensate for this at decoding.
  • If you see

    Protocol=UNKNOWN Hash=0x0 1 bits received

    it may be that the space after the initial mark is longer than


    RECORD_GAP_MICROS


    .
    This was observed for some LG air conditioner protocols. Try again with a line e.g.

    #define RECORD_GAP_MICROS 12000

    before the line

    #include

    in your .ino file.
  • To see more info supporting you to find the reason for your UNKNOWN protocol, you must enable the line

    //#define DEBUG

    in IRremoteInt.h.

Keywords searched by users: ir remote code arduino

Arduino - Ir Remote Control | Arduino Tutorial
Arduino – Ir Remote Control | Arduino Tutorial
Virtual Online Arduino Simulator And Ir Remote + Ir Receiver - Hackster.Io
Virtual Online Arduino Simulator And Ir Remote + Ir Receiver – Hackster.Io
Arduino - Ir Remote Control | Arduino Tutorial
Arduino – Ir Remote Control | Arduino Tutorial
Arduino Tutorial 31- How To Use The Infrared (Ir) Remote - Youtube
Arduino Tutorial 31- How To Use The Infrared (Ir) Remote – Youtube
Arduino Irremote Library - Project Guidance - Arduino Forum
Arduino Irremote Library – Project Guidance – Arduino Forum
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Arduino Based Ir Remote Decoder – Hackster.Io
5-Min Tutorials: Arduino Ir Remote & Receiver - Youtube
5-Min Tutorials: Arduino Ir Remote & Receiver – Youtube
Ir Communication - Sparkfun Learn
Ir Communication – Sparkfun Learn
Infrared Ir Wireless Remote Control Module Kit For Arduino
Infrared Ir Wireless Remote Control Module Kit For Arduino
How To Use Infrared Remotes And Receivers On The Arduino - Ultimate Guide  To The Arduino #26 - Youtube
How To Use Infrared Remotes And Receivers On The Arduino – Ultimate Guide To The Arduino #26 – Youtube
Using Ir Remote Controls With Arduino | Dronebot Workshop
Using Ir Remote Controls With Arduino | Dronebot Workshop
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Arduino – Control Led’S With Ir Remote Control | Random Nerd Tutorials
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Ir Remote Code Decoder Using Arduino And Lcd
Issues Trying To Use The Ir Remote - Programming Questions - Arduino Forum
Issues Trying To Use The Ir Remote – Programming Questions – Arduino Forum

See more here: kientrucannam.vn

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