I noticed that I needed to let the modem sleep for longer than 10 seconds, or there are problems on the network. Printf '\xFF\x01\x00' >$device # Power on Printf '\xFF\x01\x01' >$device # Power off This simple shell script power cycles the modem, which I run nightly using cron: I didn’t use the “NO” port (“NO = “Normally Open”) because I don’t want my modem powering off just because the relay loses power (e.g., when the Linux box reboots). When connecting the power, I used the “C” and “NC” ports (“C” = “Common” and “NC” = “Normally Closed”). Once connected, the Linux kernel happily registered it as /dev/ttyUSB0 (it uses an FTDI chip for its USB-to-Serial translation, which is supported by all modern Linux kernels). I put the relay between the modem’s power adapter and the modem itself, and connected the relay to my Linux server’s USB port for control.
Yeah, I could have simply bought a better modem, but where’s the fun in that?Īfter connecting it to the modem’s power, I wrapped it in heat shrink:Īnd its final resting place where it will happily power cycle my cable modem for its entire useful life: I got tired of walking back to the network closet, so I bought a USB relay for $30.
My office has a piece-of-junk Comcast cable modem that often needs to be rebooted.
