It's a hardware watchdog, it automatically (physically) reboots your computer if it freezes (e.g. if you're physically not around for a long time to do it yourself). Looks like crypto miners like to use them. (and I think Mars-rovers have them too - to reboot the thing if it freezes)
The basic idea is you have to keep sending "ping-commands" to it from a script running on your computer every x-minutes, indicating that your machine is still operational, and if the watchdog doesn't receive another signal before the configured timeout it PHYSICALLY resets your machine by connecting reset or power contacts using it's relay. So it has to be connected to USB for power and communication (sending these ping-notifications to it) and also to the reset (and optionally power) contacts on the motherboard (the same contacts that the physical reset and power buttons on the computer case are connected to internally).
You can also get creative with these ping notification scripts, so don't just send these ping-notifications to the device every x minute, but also check some important conditions on the machine and if they aren't satisfied anymore don't send the ping to the watchdog and it will reboot the machine. e.g. you can keep trying to access google and if the response didn't come, that means the machine lost internet connection and you might want to reboot it., that way you don't just control if the computer isn't frozen but also if it still has internet connection (or some other condition).. A software reboot in this case might be enough, but in some cases, e.g. if the machine is frozen solid, it has to be physically rebooted and that's what these devices do..
(I guess it can introduce another risk, like if the watchdog itself goes bananas and starts continuously rebooting your PC, but I hope they are simple and reliable enough..)
Oh okay that's interesting.
GAT
