Martin's corner on the web

Clapping to control RF power sockets

I did a fun experiment this evening, clap controlling RF power sockets using Funky v2‘s radio module and a sound sensor breakout module. The latter is pretty cheap one, respectively low quality and performance:



It has couple outputs: analog and digital one. The digital output goes HIGH upon audio signal from the microphone reaching certain threshold, the blueish thing is a potentiometer that sets the threshold. Power consumption is pretty high for this to run on battery, so I will have the project constantly powered via the microUSB plug. Sensitivity is bad, much worse than I expected. You get what you pay for, so let me stop complaining about it. On the positive side, the pinout is such that it can be directly plugged on a Funky v2:




I drafted a quick sketch to capture claps and send OOK pulses to a RF socket to turn it on/off using the RFM12B module. I have previously experimenting in controlling my RF power sockets with the RFM12B module, so that part of the code was ready. Range isn’t great as I use a 868Mhz RFM12B module initialized in 433Mhz as my RF power sockets are 433Mhz, but it works good. Here is a video of it working:

The project is non-invasive and safe compared to using relay/triac type of solution.