DIY USB Watchdog using Arduino Nano

[Rover9741]

Hi - I have tons of Arduino Nano’s lying around and would like to make a USB watchdog that is compatible with HiveOS. Has anyone attempted to do this yet? It seems like it should be relatively straight forward to program the Arduino if I knew what HiveOS pings to the USB device and what it expects sent back. Any ideas? Hopefully there is some code available that I can use as a starting point. Thanks!

[keaton_hiveon]

If you search arduino Linux watchdog on google and check out some of the GitHub results there should be plenty of results to get you started, but for what its worth a cheap hiveos compatible usb watchdog is like $13 on Amazon.

[Rover9741]

Thanks. Yup, I know they are cheaply available. I just want to do it as a project and then maybe program in some custom features when the watchdog is tripped.

[Rover9741]

Looking at the file /hive/opt/qinheng/hl340 it seems for Arduino Nano, the ping that get’s sent is:

# Arduino nano
mode="Arduino nano watchdog"
ping="r90p90"
reset="r2p90"

So I guess the logic on Arduino would be:

• If receive ping ‘r90p90’ reset the internal timeout.
• If not receive a ping ‘r90p90’ within internal timeout then reset computer.
• If receive reset ‘r2p90’ then reset the computer immediately.

I’m not sure what the r90p90 or r2p90 sent by HiveOS means, maybe 90 seconds timeout for watchdog, and r = reset p = power cycle off then on?

It doesn’t look like the USB watchdog has to send any data back but not totally sure.