This hardware watchdog, in the Wemos D1 Mini/Pro form factor, will reboot your Wemos if it stops responding.
The watchdog listens for a regular "heartbeat" pulse send from the Wemos and if these pulses stop then the watchdog automatically reboots the Wemos.
The brains of the watchdog is an ATtiny85 processor and the PCB allows for two different start-up and heartbeat delays to be selected without altering the ATtiny code, and also allows the users to select which pin will be monitored for the heartbeat pulse.
More details, along with the Gerber files for the PCB, the ATtiny code and sample sketches for the Wemos are on my GitHub site...
https://github.com/Peterkn2001/Wemos-D1-Mini-Hardware-Watchdog
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