In order to build this firmware,
- Install docker
- Install esputil from https://github.com/cpq/esputil
Use any ESP32-C3 board, for example ESP32-C3-DevKITM-1. Attach LED to pin 2. Then,
$ export PORT=/dev/SERIAL_PORT
$ make flash monitor
...
tick: 1001, CPU 160 MHz
tick: 2001, CPU 160 MHz
tick: 3001, CPU 160 MHz
...