My last post discussed receiving and decoding signals from the Maplin socket controller. Here, I'll describe how I went the opposite way - faking the signal to control the sockets directly with an Arduino.
As it turned out, this was a lot simpler than receiving. For one thing, the transmitter module is just 4 pins rather than 8, and can be directly driven from the Arduino with no further components. For another, I already had a representation of what the signal needed to look like - I just had to drive the transmitter input pin with the right timings.
So, here's some trivial code to do just that - it turns channel 3, ID 2 on for 3 seconds, then off for 10 seconds, repeatedly. The transmitter module plugs directly into analogue pins A3-A5, as shown in the photo. The antenna pin is left unconnected for the time being - in practice, you'd probably want to connect a suitable antenna (or just a short piece of wire, as per the data sheet) to get optimal range.
This controls the sockets just fine, and also correctly controls my receiver module. Job done! Now I just need to come up with an interesting application for this capability...