@timh I've already implemented internal watchdog but it doesn't help in case of Guru Meditation Error.
@Martinnn You and I have the same problem. Thank you for suggestion, as I can see this watchdog times is not in a form of a development board like this one: https://shop.switchdoc.com/products/switchdoc-labs-dual-watchdog-timer-board-for-arduino-raspberry-pi?variant=3340467699742. Am I right?
Thank in advance.