I made a touchpad out off two transistor a led and aluminium foil. When I touch the foil the led lights up but the arduino doesn't pick up anything on the input pin. Help plz.
That is because there is not enough voltage across that resistor to register as a logic one.
Is there no resistor in the base of that transistor?
What I see in the schematic is that you are acting as "positive voltage", allowing the Transistor to drive the ground through it, so you don't get nothing but ground on pin 12.
Shouldn't you use an Analog input?
Anyway, I'm not sure what you trying to build 
Take a look here...
http://www.paramaggarwal.com/post/2809347708/a-touchpad-using-plastic-and-aluminum-foil
Probably that is what you want
Or this
http://www.techhive.com/article/210965/Need_a_New_Touchpad_Just_put_Pencil_to_Paper.html
BTW: This looks like an interesting project to do 
American2020:
What I see in the schematic is that you are acting as "positive voltage", allowing the Transistor to drive the ground through it, so you don't get nothing but ground on pin 12.Shouldn't you use an Analog input?
Anyway, I'm not sure what you trying to build
No there will be voltage across the resistor when the transistor turns on but not enough to register as a logic one. Using an analogue input is a much better idea though.
1)Thx for the advice and do you think this circuit would be better.
http://img560.imageshack.us/img560/1815/20130403142409.jpg
- can this break my arduino because my arduino has been acting strange ever since I started this project. Everytime I come near or touch the input wire the led turns on.
Code
Int button = 12;
Into led =13;
Void setup()
{
PinMode(button, INPUT);
PinMode (led, OUTPUT);
}
void setup()
{
If(digitalRead (button)==HIGH)
{
digitalWrite(led, HIGH);
}
else{digitalWrite(led, LOW);}
}
Images to show set up
http://img32.imageshack.us/img32/1367/1365000705619.jpg
http://img194.imageshack.us/img194/7929/1365000786249.jpg
Your help is greatly appreciated.
Problem solved
Eddiexyx2:
Problem solved
Great 
The idea of the project is to have a piece of aluminum foil as a touchpad, as a button?
Eddiexyx2:
Problem solved
So your part of the bargin is to say what the problem was and how you solved it.
So your part of the bargin is to say what the problem was and how you solved it.
The problem was that the arduino wasn't reading the voltage input from the digitalpin and that when it did it was to sensitive.
After I followed what America 2020 said
Shouldn't you use an Analog input?
and look at the links he showed me
The problem was solved by using two touch pads and one transistor so that the transistor picks up the tiny Voltage that makes it across my finger, instead of using the single pad with tow that pick up the a.c. field create by my body(which was to sensitive) and used the the analog pin instead of digital.
Share a photo of the final product
I'm interested in seeing it, and see what utility can this have.