GitHub - mattbornski/Arduino-Watchdog-Circuit: The current Arduino library has bugs in the freelist implementation, which can lead to difficult to debug system hangs. For maximum reliability of my home automation projects, I built
Watchdog timer - Wikipedia
Flashing an LED with Attiny13: Timer, Watchdog timer and Sleep – Arduino, ESP8266, ESP32 & Raspberry Pi stuff
Tutorial: Using the Arduino Watchdog Timer - YouTube