DIY MaKey MaKey

I was just browsing around the internet and came across this video which described how to make your own Makey Makey board using an Arduino Leonardo. I had all the components laying around at home so I decided to make my own. Here is a video where i used 4 glasses of water to play some drums from http://www.virtualdrumming.com/. No I can't play music, well not right now anyway :-).

The Makey makey is basically a circuit that converts anything conductive - even slightly conductive (Metal, Coins, Bananas, Humans, Coke Cans, Glass of Water, etc.) into a button on your keyboard. You connect a wire from the circuit to the object you want to make into a button (key). Connect your self to the wire from the circuit labeled "hand". Done. Now the moment you touch the object it will send a key-press (example 'a') to your computer via USB. 

Using the Arduino Leonardo you can convert up-to 6 objects into a key at any given time. Unfortunately i had only 4 crocodile clips at the time with me so I made only 4 keys. You could make 6 if you wanted to.

If you want to build your own check out the video it is quite well made and goes through the whole process step by step. The circuit is ridiculously simple. The way it works is it makes a potential divider circuit between the Resistance (on one side) and your body+object (on the other side) and reads the voltage from the center. Using this voltage it figures out if you have touched the object or not. Because the resistance value is huge (10 mega-ohm and more) even slightly conductive objects can be made into keys.

Red - Connects to the Arduino Board

Blue - Output - Connects to the objects and your hand.

Purple - Resistance (Use 22 Mega-ohm  if possible, I used 10 Mega-ohm)

Once you have made the circuit you can write the code to Arduino (Available in the description at http://www.youtube.com/watch?v=WDPTA0-fbNE).

In my case I modified an Anti-Static strap to use as a connection from the circuit to my hand because i did not want to hold a wire every-time i use the circuit.

Note for people that get scared (to my surprise there were quite a few of them - I don't blame them how should they know) of using this because it might give you a jolt : It is perfectly safe to use (well unless you go Full Retard and do something incredibly stupid like connect this to the mains power in your house.)

If you don't want to build your own version of this and just want to play around. Just order one from the makey makey site and have fun.

Update: Version 2.0 - Better case, A lot more modular.