If your home internet goes down, there’s a 90% chance it’s your cable modem acting up. Sure a good old fashioned reset usually does the trick, but that doesn’t make it any less of a pain in the neck.

On his website WhatIMadeToday, Mike Diamond, a self-taught maker, has figured out a very low-cost solution using an ESP8266 01 and a small relay board. The device works by continuously pinging Google through your modem. If it doesn’t get a response back it assumes the modem is down or has crashed and will automatically power-cycle the modem.

On his site Diamond said one challenge did stump him initially:

“We all know that it takes the modem a few minutes to successfully ‘handshake’ with the line,” he wrote. “When I first set up my device, the ESP kept pinging Google during setup. As the modem hadn't yet connected, the ESP got no reply – so did a power-cycle. I was in an infinite loop getting nowhere.

“I needed the ESP to give the modem time to successfully handshake. Once this happened, the ESP would enter its regular polling of Google.”

Since installing the device Diamond said it has worked “flawlessly,” though he’s starting to believe his router need replacing altogether. He is currently working on a new version that will alert him when it is resetting the modem as well as keep a log of the date, time, and frequency of events.

Full schematics, parts lists, and build instructions are available on Diamond’s website.

Chris Wiltz is a Senior Editor at   Design News  covering emerging technologies including AI, VR/AR, blockchain, and robotics.