I love the Sonoff-S31 smart plugs. They’re cheap, well made and - most importantly - trivial to flash with ESPHome and integrate into Home Assistant. They do have one obvious draw back, though; optimized for a “traditional” US style outlet. When you try to deploy them to a power strip, you end up loosing about 50% of the outlets on the strip!

Yes, there have been loads of people doing similar things! ESPHome already has a tutorial covering exactly this!

I’m writing this up because the approach that I ended up taking was not the intended/planned approach.

The Geiger Counter

I originally pulled the trigger on this particular version because it had a built in screen attached to a micro controller.

I naïvely thought that I’d be able to get a simple UART from the 4 pins next to the microcontroller or maybe even get data directly off of the micro USB port.