esp-idf/examples/peripherals/rmt/ir_protocols

Supported Targets	ESP32	ESP32-S2	ESP32-C3	ESP32-S3

IR Protocol Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example illustrates how to encode and decode RMT signals with/to common IR protocols (e.g. NEC and RC5).

NEC and RC5 have different encoding rules, but both can be compatible to RMT data format.

The example supports building and parsing both normal and extended NEC/RC5 protocol. And also supports repeat code which would be sent out if one remote key got pressed for a specific long time.

How to Use Example

Hardware Required

• A development board with supported SoC mentioned in the above Supported Targets table
• An USB cable for power supply and programming
• A 5mm infrared LED (e.g. IR333C) used to transmit encoded IR signals
• An infrared receiver module (e.g. IRM-3638T), which integrates a demodulator and AGC circuit.

Example connection :

ESP chip	IR333C	IRM-3638T
CONFIG_EXAMPLE_RMT_TX_GPIO	Tx	×
CONFIG_EXAMPLE_RMT_RX_GPIO	×	Rx
VCC 5V	√	×
VCC 3.3V	×	√
GND	GND	GND

Configure the Project

Open the project configuration menu (idf.py menuconfig).

In the Example Configuration menu:

• Select the infrared protocol used in the example under Infrared Protocol option.
• Set the GPIO number used for transmitting the IR signal under RMT TX GPIO option.
• Set the GPIO number used for receiving the demodulated IR signal under RMT RX GPIO option.
• Set the RMT TX channel number under RMT TX Channel Number option.
• Set the RMT RX channel number under RMT RX Channel Number option.

Build and Flash

Run idf.py -p PORT flash monitor to build, flash and monitor the project.

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

Run this example, you will see the following output log (for NEC protocol):

I (2000) example: Send command 0x20 to address 0x10
I (2070) example: Scan Code  --- addr: 0x0010 cmd: 0x0020
I (2220) example: Scan Code (repeat) --- addr: 0x0010 cmd: 0x0020
I (4240) example: Send command 0x21 to address 0x10
I (4310) example: Scan Code  --- addr: 0x0010 cmd: 0x0021
I (4460) example: Scan Code (repeat) --- addr: 0x0010 cmd: 0x0021
I (6480) example: Send command 0x22 to address 0x10
I (6550) example: Scan Code  --- addr: 0x0010 cmd: 0x0022
I (6700) example: Scan Code (repeat) --- addr: 0x0010 cmd: 0x0022
I (8720) example: Send command 0x23 to address 0x10
I (8790) example: Scan Code  --- addr: 0x0010 cmd: 0x0023
I (8940) example: Scan Code (repeat) --- addr: 0x0010 cmd: 0x0023
I (10960) example: Send command 0x24 to address 0x10
I (11030) example: Scan Code  --- addr: 0x0010 cmd: 0x0024
I (11180) example: Scan Code (repeat) --- addr: 0x0010 cmd: 0x0024

Troubleshooting

For any technical queries, please open an [issue] (https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you soon.