Arduino Leonardo --> Makey Makey (Need help) (How to?)

{TL;DR} → see bottom

Hello
I am still quite new in the arduino world. I am here because of my rather unsuccesful attempts to create a real life gamepad or an arcade dance floor like thing. It’s based of a video I’ve found online using the makey makey. There, you connect yourself to ground and your objects to analog pins. When you touch the objects, the analogValue is zero, and it presses a button. It sounded really easy to me so I started working.

So I connected the Analog pins to cardboard plates wrapped around in aluminium foil and read their values. If these values drop below 10 (since I’m grounded) when I touch them, I let the arduino press a key. Now the thing I’ve remarked is that if I add multiple wires and pins, they are starting to interfere. When one becoms zero there is a big chance that another one will become zero too. Any idea how I could solve this?

In the meantime I used two arduino nano’s with each three buttons on analog pins A0, A4 and A7. Again no succes… They still interfere a bit, however this is already better, and in my signal there is a lot of noise… This means that some buttons don’t press sometimes, while others do when I don’t press them… In general, this application works, but it isn’t reliable enough to actually play with it.
This is very frustrating. I’ll add the sketches for my 3 arduino’s as attachment so you could read them through if you would want.

So I’m quite desperate and looking for options. I’ve already worked and experimented more than 7 hours on this, but nothing seems to lead in the right direction.
I also can’t seem to find any people who are trustable and succesfully made a similar device.
I only found this sketch along with this video, which I could still try, but it seems that it will have the same interference problem (or am I wrong). And this forum post, stating that it is just a modified arduino, and that they would have given the sketch when it was finished, but I can’t seem to find that either…

Please Help
Greetings
Reds Duty

{TL;DR} → I’m trying to use my Arduino Leonardo as a makey makey, but I can’t seem to figure it out

Leo III.zip (3.14 KB)

If you are creating home made touch-sensitive switches connected to Arduino pins, you'll probably have to experiment with high value pull up resistors on the pins (maybe 100k to 10M) to keep it stable enough from interference while still sensitive enough to respond to touch.

You may find some tips here: https://www.google.ch/?gws_rd=ssl#q=touch+sensitive+switch+arduino

Thank you very much! I will look into it and let you know. When I figure it out I will create a detailed guide on how to do this so others can do it more easily. :) :)