esp-idf/examples/peripherals/rmt/morse_code/README.md

RMT Transmit Example -- Morse Code

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

This example mainly illustrates how to transmit the Morse code using the RMT driver.

How to Use Example

Hardware Required

• A development board with ESP32 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
• A USB cable for Power supply and programming
• A LED, a speaker or an earphone

Connection :

             330R            LED     
GPIO18 +----/\/\/\----+------|>|-----+ GND
                      |    
                      | /|
                     +-+ |   Speaker
                     | | |     or
                     +-+ |  earphone
                      | \|
                      |
                      +--------------+ GND

Configure the Project

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

In the Example Configuration menu:

• Set the GPIO number used for transmitting the IR signal under RMT TX GPIO optin.

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 all the steps to configure and use the ESP-IDF to build projects.

• ESP-IDF Getting Started Guide on ESP32
• ESP-IDF Getting Started Guide on ESP32-S2
• ESP-IDF Getting Started Guide on ESP32-C3

Example Output

To be able to see and hear the message output by the RMT, connect an LED and a speaker or an earphone (be careful it might make a large noise) to the GPIO you set in the menuconfig.

Run the example, you will see the following output log:

...
I (304) example: Configuring transmitter
I (2814) example: Transmission complete
...

Troubleshooting

For any technical queries, please open an issue on GitHub. We will get back to you soon.