Thanks for the suggestions. I don't really have boot problems anymore. I'm concerned about problems typically caused by bugs in the software. I sometimes upload firmware that aborts and causes reboot loop for example. Sometimes the board gets "frozen" — doesn't reboot but is also not working properl...

I'm using pin 12 for pwm output and that seems to be totally OK. Pin 12 has internal pulldown anyway as per the authorative boot mode description: https://docs.espressif.com/projects/esptool/en/latest/esp32/advanced-topics/boot-mode-selection.html adding pull-down resistor won't help if the pwm subs...

there is second thermostat that cuts off power at higher temperature and thermal fuse at even higher temperature. But I'd prefer not to have to rely on them. I just need to understand if it's normal to have the pwm output freeze in high mode during board restart (for example) and can I do something ...

I'm controlling heater via SSR. The SSR on it's side is controlled by ESP32's PWM library with zerocross sync configured. Sometimes the board freezes or enters reboot loop (when code is buggy for example) and in 1 of 50 of such cases the pwm output remains high and the heater works non-stop and that...

I could use it as pre-compiled lib. But still can't figure out where's the arduino.a or how to include it.

Using ccache btw and the speed-up is impressive.

Thanks, I'll give that a try.

What are my options to minimize re-compilations of the Arduino component? I'd like to re-build the arduino component only when I touch something relevant in the sdkconfig. I'm pretty fine with a manual process (e.g. configure, build, copy something somewhere)

using the manual https://docs.espressif.com/projects/arduino-esp32/en/latest/esp-idf_component.html I get Arduino as component working and that's great. However I don't want to checkout the arduino git repo in each project or build it every time I touch the sdkconfig. The manual says "For a simplifi...

thanks, this solved it!
added 4.7uf capacitor GND <> RST and reset works as expected.

plus part of the annoying whine coming from the cubieboard is gone. very weird?

I'm using two identical lolin boards as in the title to develop basic controller (thermo sensor, ssr, dimmer periphery) and every now & then they start requiring pin0 to be pulled down in order to flash. The tty works without problem. when this happens typically the board is connected to a raspberry...