esp-idf/examples/19_sigmadelta/README.md

Example: sigma_delta modulation

This example uses the sigma_delta output modulation driver to generate modulated output on a GPIO.

By default the GPIO output is 4, however you can edit this in the sigmadelta_init() function inside main/sigmadelta_test.c.

If you connect an LED to the output GPIO, you will see it blinking slowly.