Newbie help! Knock sensor..


I just found an old Arduino Duemilanove that I haven't really used. So I tried to make this knock sensor:

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?

Cheers, Niku

Does the piezo still work as buzzer?

Yeah, the piezo is still working as a buzzer, I even tried with another piezo.. So im kinda frustrated bacause I can not find the problem :)