In light sleep mode, digital peripherals, most of the RAM, and CPUs are clock-gated, and supply voltage is reduced. Upon exit from light sleep, peripherals and CPUs resume operation, their internal state is preserved. Documentation https://docs.espressif.com/projects/esp-idf/en/v4.4.5/esp32c3/api-reference/system/sleep_modes.html Example light sleep function Used with ESP32 C3