| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-H2 | ESP32-P4 | ESP32-S2 | ESP32-S3 | | ----------------- | ----- | -------- | -------- | -------- | -------- | -------- | -------- | -------- | # _LEDC Basic Example_ (See the README.md file in the upper level 'examples' directory for more information about examples.) This example shows how to use the LEDC to generate a PWM signal using the `LOW SPEED` mode. To use `HIGH SPEED` mode check if the selected SoC supports this mode. ## How to use example ### Hardware Required * A development board with any Espressif SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.) * A USB cable for power supply and programming Connect the GPIO to an oscilloscope to see the generated signal: |ledc channel| GPIO | |:----------:|:-----:| | Channel 0 | GPIO5 | ### Configure the project The example uses fixed PWM frequency of 4 kHz, duty cycle in 50%, and output GPIO pin. To change them, adjust `LEDC_FREQUENCY`, `LEDC_DUTY`, `LEDC_OUTPUT_IO` macros at the top of ledc_basic_example_main.c. Depending on the selected `LEDC_FREQUENCY`, you will need to change the `LEDC_DUTY_RES`. To dynamically set the duty and frequency, you can use the following functions: To set the frequency to 2.5 kHZ i.e: ```c ledc_set_freq(LEDC_MODE, LEDC_TIMER, 2500); ``` Now set the duty to 100% i.e: ```c ledc_set_duty(LEDC_MODE, LEDC_CHANNEL, 8192); ledc_update_duty(LEDC_MODE, LEDC_CHANNEL); ``` To change the duty cycle you need to calculate the duty range according to the duty resolution. If duty resolution is 13 bits: Duty range: `0 to (2 ** 13) = 8191` where 0 is 0% and 8192 is 100%. ### Build and Flash * [ESP-IDF Getting Started Guide](https://idf.espressif.com/) Build the project and flash it to the board, then run monitor tool to view serial output: ```bash idf.py -p PORT 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 Running this example, you will see the PWM signal with a duty cycle of 50%. ![PWM](image/ledc_pwm_signal.png) ## Troubleshooting * Duty Resolution * If you get the following error log `ledc: requested frequency and duty resolution can not be achieved, try reducing freq_hz or duty_resolution.` you need to change the `LEDC_DUTY_RES` to a lower resolution and change the range of the duty. * Programming fail * Hardware connection is not correct: run `idf.py -p PORT monitor`, and reboot your board to see if there are any output logs. * The baud rate for downloading is too high: lower your baud rate in the `menuconfig` menu, and try again. For any technical queries, please open an [issue](https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you soon.