Building for ESP32C3 with hardware RTC 32.768KHz crystal

[feeley]

Is there a way to build micropython on ESP32C3 so that the RTC is configured as the "external low-speed (32 kHz) crystal clock" (on pins GPIO0 and GPIO1)?

[2dof]

based on -C3 APIdescription You can use External 32kHz Crystal - optional (XTAL32K), but with micropython You need change sdkconfig file , set CONFIG_ESP32_RTC_CLOCK_SOURCE_EXTERNAL_CRYSTAL=1 and build custom firmware. issues/3764

see also user guide section: 6.2 Clock - based on user guide external 32.7 XTAL is used for "low-power devices, such as RTC module and low-power peripherals" but not for a CPU clock source.

[feeley]

Thanks! I will give it a try.