It would be nice to get the parts, assemble everything, and play drums!

So far, the only thing I had to make myself was the ADC board. I found that someone already made an ADC board for the Pi. It's a kit, so you have to solder it yourself, but that's so much easier, and more professional than the one I made... The RaspPiO Analog Zero is available here: http://rasp.io/analogzero/, and it costs about £10, which isn't a lot. It comes with a MCP3008, which is compatible with eXaDrums, so that's perfect. I ordered one, and should get it next week (Tuesday or Wednesday).

Another good news is that the hi-hat tests are quite encouraging. Actually, it's fair to say that it works, as shown in this video in which you can hear the transition from the closed to opened hi-hat (audio only):

The pedal will be made of a photodiode and an led.For the video, I just moved the led around, to simulate and open/close state.

All of this means that we're well on our way to a real, proper usable drum module. It can already handle drums, cymbals, and hi-hat. Moreover, the "Analog Zero" board, has got a prototyping area to which I will solder the resistor and LED of the hi-hat pedal , so it is now oder, assemble, and play drums!

Obviously, I'll keep working on the software, to make a very complete drum module (including rhythm coach, etc...), but the easier hardware assembly is also a good opportunity to build a prototype, and test a "real" drum kit, with 8 sensors (for example a 2 toms + 1 snare + 1 bass drum + 1 hi-hat + 1 crash + 1 ride drum kit). I will start that shortly (need to order sensors first) and keep working on the software to make it all happen!