I just found an old Arduino Duemilanove that I haven't really used. So I tried to make this knock sensor: http://www.arduino.cc/en/Tutorial/Knock
I only had 330ohm resistors so I used them instead, tried with one and 4 in a series. But all my serial monitor shows is zeroes (when using analogRead(A0); ).
If the piezo is not connected it seems to show random values but when I put it in I just get zeroes... Anyone know where the problem could be?
Ive tried with 2 different duemilanoe's but get the same problem.
The same thing with a Light Dependant Resistor.
Haven't tried with another cable or computer yet but maybe that could help?