Controlling a British Gas WR1 Receiver with an Arduino

Over the holiday season I started looking at whether my boiler, a Worcester Bosch Greenstar 28i, was compatible with the Nest thermostat. After some Googling I began to wonder whether I could make my own controller and began investigating how the existing wireless programmer might function. The programmer currently in use is a British Gas WR1, which looks to be a re-branded Drayton Digistat device.

British Gas WR1

After removing the programmer from its wall mounting plate I immediately noticed a sticker indicating it operated using 433MHz. Thankfully this is part of the unlicensed spectrum meaning transmitters are likely to be readily available. Sure enough, there are 433MHz transmitter/receiver pairs available in the UK for just £2 on eBay. I immediately bought myself an Arduino, some cables, a breadboard and waited eagerly for everything to arrive.

My plan was to create a single channel logic analyser as described in Steven Hale’s excellent blog post, using the soundcard in my laptop to capture what my existing programmer transmits. My soldering ability leaves a lot to be desired, so I’ll spare you a photo and include a diagram that is likely to be much more useful:
Sound card logic analyser
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