If you find this library useful, please give it a star.

🌎 Google Translate

Features

• Total of 50 IR protocols supported.
• Up to 39 protocols can be enabled for receive at the same time, because some of the 50 protocols are quite similar and conflicts with each other.
• 39 protocols are available for send.
• Low memory footprint. FLASH usage in bytes: 1500 for one protocol, 4300 for 15 main and 8000 for all 39 protocols.
• RAM usage in bytes: 52, 73 and 100.

Nano running AllProtocol example	YouTube Video	Instructable

List of protocols

Sony SIRCS     NEC + APPLE + ONKYO     Samsung + Samsg32     Kaseikyo

JVC     NEC16 + NEC42     Matsushita     DENON     Sharp     RC5     RC6 & RC6A     IR60 (SDA2008) Grundig     Siemens Gigaset     Nokia

BOSE     Kathrein     NUBERT     FAN (ventilator)     SPEAKER (~NUBERT)     Bang & Olufsen     RECS80 (SAA3004)
    RECS80EXT (SAA3008)     Thomson     NIKON camera     Netbox keyboard     ORTEK (Hama)     Telefunken 1560
    FDC3402 keyboard     RC Car     iRobot Roomba     RUWIDO     T-Home     A1 TV BOX    LEGO Power RC
    RCMM 12,24, or 32     LG Air Condition     Samsung48     Merlin     Pentax     S100     ACP24     TECHNICS
    PANASONIC Beamer     Mitsubishi Aircond     VINCENT     SAMSUNG AH     GREE CLIMATE     RCII T+A
    RADIO e.g. TEVION     METZ

NEC     Kaseiko     Denon     RC6     Samsung + Samsg32   were successfully tested in interrupt mode, but there are many protocols which in principle cannot be decoded in this mode.

Features

• You may use every pin for input or output.
• Interrupt mode for major protocols.
• Callback after successful receive of a command.
• Support for inverted feedback LED (for send and receive feedback).
• Support for inverted IR output for LED connected to VCC.
• Unmodulated IR signal output enables direct replacment of an IR receiver circuit.
• Compatible with Arduino tone library.
• Send can also also wait for trailing space/gap.

Restrictions

• Send IR frequency is fixed at 38 kHz.
  

Minimal version

For applications only requiring NEC protocol, there is a receiver which has very small codesize of 500 bytes and does NOT require any timer. See the MinimalReceiver and IRDispatcherDemo example how to use it. Mapping of pins to interrupts can be found here.

Schematic for Arduino Uno

The VS1838B is used as receiver for all examples and tests. This module has a 120 µs on/low and a 100 µs off/high delay between received signal and output. So it shortens the mark and extends the space by 20 µs.	IR-Receiver connection	Serial LCD connection

Supported Arduino architectures / CPU's / boards

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.

* 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

Pin usage

You may use every pin for input or output, just define it like #define IRMP_INPUT_PIN 2 and #define IRSND_OUTPUT_PIN 3. The PWM of the output pin is generated by software bit banging.

Dynamic pins numbers

If you want to use pin numbers for input, output and LED feedback specified at runtime, you must define IRMP_IRSND_ALLOW_DYNAMIC_PINS. See ReceiveAndSendDynamicPins example.
The irmp_init and irsnd_init function then allows up to 3 parameters uint_fast8_t aIrmpInputPin/aIrsndOutputPin, uint_fast8_t aIrmpFeedbackLedPin, bool aIrmpLedFeedbackPinIsActiveLow.
Be aware, only one pin and enable flag for receive and send feedback LED is supported.

Receiving and sending simultaneously

Receiving and sending is possible with this library, but since we use only 1 timer, receiving is inhibited while sending the IR signal.
Sending the IR signal starts with saving current timer configuration, setting the timer to the send configuration / frequency, sending the signal (and waiting for the gap after the signal) and then automatically reset the timer to its previous (receiving) configuration.

API

IRMP

// Init functions
void irmp_init (void);
void irmp_init(uint_fast8_t aIrmpInputPin);
void irmp_init(uint_fast8_t aIrmpInputPin, uint_fast8_t aIrmpFeedbackLedPin);
void irmp_init(uint_fast8_t aIrmpInputPin, uint_fast8_t aIrmpFeedbackLedPin, bool aIrmpLedFeedbackPinIsActiveLow);
void irmp_register_complete_callback_function(void (*aCompleteCallbackFunction)(void));

// Info function
bool irmp_IsBusy();
void irmp_print_active_protocols(Print *aSerial);

// Main check for result function used in loop()
bool irmp_get_data (IRMP_DATA *)

// Result print functions
void irmp_result_print(Print *aSerial, IRMP_DATA * aIRMPDataPtr);
void irmp_result_print(IRMP_DATA *aIRMPDataPtr);

IRSND

// Init functions
void irsnd_init (void);
// 3 additional init functions if IRMP_IRSND_ALLOW_DYNAMIC_PINS is defined
void irsnd_init(uint_fast8_t aIrsndOutputPin);
void irsnd_init(uint_fast8_t aIrsndOutputPin, uint_fast8_t aIrmpFeedbackLedPin);
void irsnd_init(uint_fast8_t aIrsndOutputPin, uint_fast8_t aIrmpFeedbackLedPin, bool aIrmpLedFeedbackPinIsActiveLow);

// Send function - sends frame AND trailing space
bool irsnd_send_data (IRMP_DATA *, uint8_t);

// Info functions
bool irsnd_is_busy (void);

void irsnd_stop (void);

IRMP and IRSND

// LED feedback function
void irmp_irsnd_LEDFeedback(bool aEnableBlinkLed);

// Timer management functions for 
void disableIRTimerInterrupt(void);
void enableIRTimerInterrupt(void);
void storeIRTimer(void);
void restoreIRTimer(void);

Examples

In order to fit the examples to the 8K flash of ATtiny85 and ATtiny88, the Arduino library ATtinySerialOut is required for this CPU's.

AllProtocols

Receives up to 40 protocols concurrently and displays the short result on a 1602 LCD. The LCD can be connected parallel or serial (I2C).

SimpleReceiver + SimpleSender

This examples are a good starting point.
SimpleReceiver can be tested online with WOKWI. Click on the receiver while simulation is running to specify individual IR codes.

MinimalReceiver + MinimalSender

If code size matters, look at these examples.
The MinimalReceiver example uses the TinyReceiver library which can only receive NEC and FAST codes, but does not require any timer.
MinimalReceiver can be tested online with WOKWI. Click on the receiver while simulation is running to specify individual IR codes.

SmallReceiver

If the protocol is not NEC and code size matters, look at this example.
MinimalReceiver 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 IR codes.

Compile options / macros for this library

To customize the library to different requirements, there are some compile options / macros available, which must be set before including the library e.g. with #include <irmp.hpp>.
Modify it by setting the value to 1 or 0. Or define the macro with the -D compiler option for global compile (the latter is not possible with the Arduino IDE, so consider using Sloeber.

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 with Sloeber IDE

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

Timer usage

The IRMP receive library works by polling the input pin at a rate of 10 to 20 kHz. Default is 15 kHz.
Some protocols (NEC, Kaseiko, Denon, RC6, Samsung + Samsg32) can be received without timer usage, just by using interrupts from the input pin by defining IRMP_ENABLE_PIN_CHANGE_INTERRUPT. There are many protocols which in principle cannot be decoded in this mode. See Interrupt example.
In interrupt mode, the micros() function is used as timebase.

The IRMP send library works by bit banging the output pin at a frequency of 38 kHz. This avoids blocking waits and allows to choose an arbitrary pin, you are not restricted to PWM generating pins like pin 3 or 11. The interrupts for send pin bit banging require 50% CPU time on a 16 MHz AVR.
If both receiving and sending is required, the timer is set up for receiving and reconfigured for the duration of sending data, thus preventing receiving in polling mode while sending data.
The tone library (using timer 2) is still available. You can use it alternating with IR receive and send, see ReceiveAndSend example.

• For AVR timer 2 (Tone timer) is used for receiving and sending. For variants, which have no timer 2 like ATtiny85 or ATtiny167, timer 1 (or timer 0 for digispark core) is used.
• For SAMD TC3 is used.
• For Apollo3 Timer 3 segment B is used.
• For ESP8266 and ESP32 timer1 is used.
• For STM32 (BluePill) timer 3 (Servo timer) channel 1 is used as default.
  

Tips and tricks

• To port the library to another device, you merely have to extend IRTimer.hpp.
• The minimal CPU clock required for receiving is 8MHz.
• To save power, you can use the interrupt mode or polling mode with no-sending detection and power down sleep. This is not available for ATtiny85 running with the High Speed PLL clock (as on Digispark boards) because of the high startup time from sleep of 4 to 5 ms for this clock. You have to use the ISP to rewrite the CKSEL fuses and to load the program.
  • The best way to increase the IR power is to use 2 or 3 IR diodes in series. One diode requires 1.1 to 1.5 volt so you can supply 3 diodes with a 5 volt output.To keep the current, you must reduce the resistor by (5 - 1.3) / (5 - 2.6) = 1.5 e.g. from 150 Ω to 100 Ω for 25 mA and 2 diodes with 1.3 volt and a 5 volt supply. For 3 diodes it requires factor 2.5 e.g. from 150 Ω to 60 Ω.
• A lot of recent IR diodes can be powered with max. 200 mA at 50% duty cycle, but for this you will require an external driver / transistor / (mos)fet.
• In order to fit the examples to the 8K flash of ATtiny85 and ATtiny88, the Arduino library ATtinySerialOut is required for this CPU's.

AllProtocols example

Serial LCD output	Arduino Serial Monitor output

Sample Protocols

Documentation at mikrocontroller.net

English

http://www.mikrocontroller.net/articles/IRMP_-_english
http://www.mikrocontroller.net/articles/IRSND_-_english

German

http://www.mikrocontroller.net/articles/IRMP
http://www.mikrocontroller.net/articles/IRSND

German Forum

https://www.mikrocontroller.net/topic/irmp-infrared-multi-protocol-decoder?goto=6996113#6996137

Revision History

Version 3.6.4

Version 3.6.3

• Fixed ESP32 send timer bug.

Version 3.6.2

• Fixed FEEDBACK_LED_IS_ACTIVE_LOW bug.
• Added Kaseikyo Panasonic decode.
• Added ATtiny88 / AVR timer1 timer support.
• Fixed unexpected leading space for irsnd_send_data(...,false).

Version 3.6.1

• Fixed NO_LED_FEEDBACK_CODE bug.

Version 3.6.0

• Improved timings by J�rg R.
• Support for NEC 8 bit address.
• Fixed ATmega4809 bug.
• RP2040 support added.

Version 3.5.1

• Fixed ESP8266 F_CPU error introduced with 3.4.1.

Version 3.5.0

• Renamed .c.h and .cpp.h to .hpp. You must change: #include to: #include !
• Fix Timer1 initialization for ATtinyX7 parts for ATTinyCore.
• Modifying digitalWriteFast.h to be compatible with ATTinyCore Digispark Pro default pin mapping.
• Renamed initPCIInterrupt() to enablePCIInterrupt() and added disablePCIInterrupt().
• Changed return value for irsnd_send_data() to be false on error conditions.
• Fixed ICACHE_RAM_ATTR error introduced with 3.4.1.

Version 3.4.1

• Changed default pins for ATmega328 platform from 3,4,5 to 2,3,4.
• Adapted to TinyCore 0.0.7.
• Renamed macro IRMP_TIMING_TEST_PIN to IR_TIMING_TEST_PIN.
• Changed pins in PinDefinitionsAndMore.h.
• Never send a trailing space for Arduino.
• ATTiny88 support.

Version 3.4.0

• Added ATtiny3217 / TinyCore support.
• Added Melinera protocol and single repeat for NEC from upstream.

Version 3.3.5

• Added TinyIRReceiver and updated IRDispatcherDemo examples.
• Fixed "enabling OUTPUT for dynamic pin" bug.
• Improved Apollo3 and MegaCore support.

Version 3.3.4

• Removed convenience function irmp_tone(), since it statically allocates the tone interrupt vector.

Version 3.3.3

• Added ATmega8 support.
• Added IRSND_GENERATE_NO_SEND_RF compile switch.
• Added function irsnd_data_print().
• New SendAllProtocols example.
• New DispatcherDemo example.
• Added IRMP_FEEDBACK_LED_PIN compile switch.
• Removed IRMP16 protocol from the all list.
• Added missing Leonardo support.

Version 3.3.2

• Added missing Medion entry in irmp_protocol_names.
• Added function irmp_print_protocol_name().
• Added Teensyduino support.
• Fixed macro redefinitions in IRSND.

Version 3.3.1

• Fix for function bool irmp_IsBusy() if IRMP_ENABLE_PIN_CHANGE_INTERRUPT is defined.

Version 3.3.0

• Added function bool irmp_IsBusy().

Version 3.2.3

• Fixed warning for missing USE_ONE_TIMER_FOR_IRMP_AND_IRSND macro.

Version 3.2.2

• Removed blocking wait for ATmega32U4 Serial in examples.
• Restored missing line reset interrupt flags found by user yumkam.
• Fixed bug for sending only on no AVR platforms.

Version 3.2.1

• Fixed bug in feedback LED handling for dynamic pins for send and receive.
• Fixed wrong timer selection for STM32F1xx / ARDUINO_ARCH_STM32.

Version 3.2.0

• MBED support for Arduino Nano 33 BLE.
• Added ARDUINO_ARCH_STM32 definition.
• Fixed ESP8266 wrong memcpy_p definition introduced in 3.0.0.

Version 3.1.2

• Fixed interrupt mode bug introduced by merging upstream code for version 3.1.0.
• Fixed ESP8266 wrong memcpy_p definition introduced in 3.0.0. - Fix was not complete :-(. Use 3.2.0.

Version 3.1.1

• Added MinimalReceiver example.

Version 3.1.0

• Added RF_MEDION protocol
• IRAM attribute etc.
• Fixed bug irmp_init used instead of irsnd_init
• New function irmp_print_active_protocols().
• Use timer3 for ESP32.
• Fix missing check for LED pin == 0.
• Merged upstream v3.2.2 + IRMP_ENABLE_RELEASE_DETECTION.
• Dynamic pin for feedback LED added.

Version 3.0.0

• Support of RF (433MHz) remotes. 2 protocols Generic 24 bit format and X10 format added.
• MegaAVR (ATmega4809) support.
• Added IRMP_IRSND_ALLOW_DYNAMIC_PINS and extended irmp_init() and irsnd_init()to allow input, output and LED feedback pin selection at runtime.
• Support more protocols simultaneously on 32 bit CPUs.
• Use same pin and enable flag for receive and send feedback LED.
• New function irmp_print_active_protocols().

Version 2.2.1

• Improved pin layout.
• Fixed bug with stm32duino 1.9.
• Version number.
• Blink13 -> LEDFeedback.

Version 2.2.0

• Supported Apollo3 platform.
• Fixed DigisparkPro bug.

Version 2.1.0

• Supported SAMD platform.
• IRSND enabled for non AVR platforms.

Version 2.0.0

• Added IR send fuctionality (IRSND).
• Use TIMER2_COMPB_vect to be compatible with tone library.
• No longer required to call initPCIInterrupt() manually if IRMP_ENABLE_PIN_CHANGE_INTERRUPT is set.
• Separated code for timer to IRTimer.hpp.
• Separated code for Pin change interrupt to irmpPinChangeInterrupt.hpp.
• Fixed wrong pin numbers for BluePill.

Version 1.2.2

• Fixed bugs introduced in 1.2.1.

Version 1.2.1

• Bug for AVR architecture fixed.
• ATtiny85 + ATtiny167 support for ATTinyCore and Digistump core.
• Support for "Generic STM32F1 series" from "STM32 Boards (selected from submenu)" of Arduino Board manager.

Version 1.2.0 - This version contains a bug for the AVR architecture

• Added STM32 M3 (BluePill) support.

Version 1.1.0

• Added functions irmp_disable_timer_interrupt() and irmp_enable_timer_interrupt().
• Added function irmp_result_print(Print *aSerial).
• Improved examples.

Version 1.0.1

• Added ESP8266 + ESP32 support.

CI

The library examples are tested with GitHub Actions for the following boards:

• arduino:avr:uno
• arduino:avr:leonardo
• arduino:avr:mega
• arduino:megaavr:nona4809:mode=off
• arduino:samd:arduino_zero_native
• arduino:mbed:nano33ble
• arduino:mbed_rp2040:pico
• rp2040:rp2040:arduino_nano_connect
• digistump:avr:digispark-tiny:clock=clock16
• ATTinyCore:avr:attinyx5micr:LTO=enable,sketchclock=8pll
• ATTinyCore:avr:attinyx7micr:LTO=enable,sketchclock=16external,pinmapping=new,millis=enabled
• ATTinyCore:avr:attinyx8micr:LTO=enable,sketchclock=16external,pinmapping=mhtiny,millis=enabled # ATtiny88 China clone board @16 MHz
• TinyCore:avr:tiny32
• esp8266:esp8266:d1_mini:eesz=4M3M,xtal=80
• esp32:esp32:featheresp32:FlashFreq=80
• STMicroelectronics:stm32:GenF1:pnum=BLUEPILL_F103C8
• STMicroelectronics:stm32:GenL0:pnum=THUNDERPACK_L072
• stm32duino:STM32F1:genericSTM32F103C
• SparkFun:apollo3:sfe_artemis_nano