This example uses the remote control (RMT) peripheral to transmit and receive codes for the NEC infrared remote protocol.
## How to Use Example
### Hardware Required
To run this example, you need to prepare a development board with esp32 SoC(e.g., ESP32_Core_board, ESP-WORVER_KIT etc) and a USB cable for power supply and programming.
By default, this example runs a self test which assumes the TX pin (GPIO18) and RX pin (GPIO19) are _connected together_.
To disable self-test mode, comment out RMT_RX_SELF_TEST in infrared_nec_main.c, after which, you need to connect a IR transmitter and a receiver to GPIO18 and GPIO19.
The TX pin and RX pin can be modified in top of the main/infrared_nec_main.c file.
```
#define RMT_TX_GPIO_NUM 18 /*!< GPIO number for transmitter signal */
#define RMT_RX_GPIO_NUM 19 /*!< GPIO number for receiver */
```
### Configure the Project
```
make menuconfig
```
* Set serial port under Serial Flasher Options.
### Build and Flash
Build the project and flash it to the board, then run monitor tool to view serial output:
```
make -j4 flash monitor
```
(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:
```
NEC: RMT TX DATA
NEC: RMT RCV --- addr: 0xee11 cmd: 0xff00
NEC: RMT RCV --- addr: 0xed12 cmd: 0xfe01
NEC: RMT RCV --- addr: 0xec13 cmd: 0xfd02
NEC: RMT RCV --- addr: 0xeb14 cmd: 0xfc03
NEC: RMT RCV --- addr: 0xea15 cmd: 0xfb04
NEC: RMT RCV --- addr: 0xe916 cmd: 0xfa05
NEC: RMT RCV --- addr: 0xe817 cmd: 0xf906
NEC: RMT RCV --- addr: 0xe718 cmd: 0xf807
NEC: RMT RCV --- addr: 0xe619 cmd: 0xf708
NEC: RMT RCV --- addr: 0xe51a cmd: 0xf609
NEC: RMT RCV --- addr: 0xe41b cmd: 0xf50a
NEC: RMT RCV --- addr: 0xe31c cmd: 0xf40b
NEC: RMT RCV --- addr: 0xe21d cmd: 0xf30c
NEC: RMT RCV --- addr: 0xe11e cmd: 0xf20d
NEC: RMT RCV --- addr: 0xe01f cmd: 0xf10e
NEC: RMT RCV --- addr: 0xdf20 cmd: 0xf00f
NEC: RMT RCV --- addr: 0xde21 cmd: 0xef10
NEC: RMT RCV --- addr: 0xdd22 cmd: 0xee11
NEC: RMT RCV --- addr: 0xdc23 cmd: 0xed12
NEC: RMT RCV --- addr: 0xdb24 cmd: 0xec13
NEC: RMT RCV --- addr: 0xda25 cmd: 0xeb14
```
## Troubleshooting
* Programming fail
* To check whether the hardware connection of UART is correct, you can run `make monitor` and reboot your board to see if there are any output logs.
* Your download baud-rate is too high. please lower your download baud-rate in menuconfig and try again.
If any problems that can't be resolved, please open an issue in GitHub(https://github.com/espressif/esp-idf/issues), we will reply to you soon.