This project is largley based off of Progman2K's repo https://github.com/Progman2k/USB_Watchdog
and supports the following (HID) usb-watchdog device:
lsusb output:
ID 5131:2007 MSR MSR-101U Mini HID magnetic card reader
It's confusing as there seems to be many devices like this on the market using the same 5131:2007 id.
The main difference between this device and Progman2K's device and that this device doesn't have an integrated power button, also the command format is different.
This device accepts the following commands/messages which are comprised of two bytes:
ping: ['0x1e', '0x00']
restart: ['0xff', '0x55']
If the device doesn't receive a "ping" message within the timeout period, the relays will be triggered, which causes the connected system to reboot.
initial timeout: 120 seconds this is the inital timeout value placed on the device, which will change after the device receives its first ping message
normal timeout: 290 seconds after the device receives its first ping message, the timeout value changes from 120 seconds to (approx) 290 seconds
After a ping message is sent to the usb watchdog device, a read operation is performed to confirm that the device actually received the message.
If these values differ, an error message will be displayed showing what bytes were transferred and what bytes were received.
WARNING Watchdog's TX and RX don't match
TX 0x1e00
RX 0x0eff
** errors like this should never happen, just know that the receipt of each transmitted ping message is being verfied.
python libraries
This script requires the pyusb and systemd-python python libraries
You can install them via your distro's package management tool or via pip3
fedora package install
dnf install python3-pyusb python3-systemd
pip package install
pip3 install pyusb systemd-python
command options
Should be pretty self-explanatory
./usb_watchdog.py --help
usage: usb_watchdog.py [-h] [-i INTERVAL] [-q] [-r] [-d] [-u USBVENDOR] [-p USBPRODUCT]
options:
-h, --help Show this help message and exit
-i INTERVAL, --interval INTERVAL
Watchdog ping interval in seconds, should be under 230, default value: 10
-q, --quiet Silences all output
-r, --restart Restart system via the watchdog USB device
-d, --debug Output verbose debugging information
--date Output date/time with each logging entry
--systemd Use the systemd/journald logging mechanism
-u USBVENDOR, --usbvendor USBVENDOR
usb vendor id, default value: 5131
-p USBPRODUCT, --usbproduct USBPRODUCT
usb product id, default value: 2007
Each time the device successfully receives a ping message, the blue led on the device will blink.
setup the usb_watchdog service
git clone https://github.com/leifliddy/usb-watchdog.git
cd usb-watchdog
sudo cp usb_watchdog.py /usr/local/sbin/
sudo cp usb_watchdog.service /etc/systemd/system/
systemctl enable --now usb_watchdog.service
running journalctl -f will show you the ping intervals
Dec 24 06:31:01 black.example.com usb_watchdog[117201]: pinging!
Dec 24 06:31:11 black.example.com usb_watchdog[117201]: pinging!
Dec 24 06:31:21 black.example.com usb_watchdog[117201]: pinging!
Dec 24 06:31:31 black.example.com usb_watchdog[117201]: pinging!
Dec 24 06:31:41 black.example.com usb_watchdog[117201]: pinging!
Also, you can start the usb_watchdog service without needing the usb-watchdog device to be plugged in.
If/when the device is plugged in at a later time, the service will identify, connect, and start communicating with it.