have I fried an analog in?


First day using the Arduino Duemilanove.

I was playing around with the Knock and Graph examples, I had a piezo transducer connected with a resistor, and was looking looking at the waveform of me hitting the transducer in Processing.

All of a sudden the arduino started sending a value of around 400 constantly from the analogue input, and no amount of restarting/pulling the plug will change this.

If I connect the analogue input to ground I get a zero readout, and if I connect to +5v or +3v I get appropriate readings, but with the transducer connected I get 400, with a little disturbance if I hit the transducer.

Have I somehow damaged the input, or is there something else I can try to fix the problem?

The five other inputs appear to be working fine.


So the transducer works fine on the other pins but not that one?

Yes, and I've tried different transducers as well.

Try using a potentiometer on the pin, and tell us if it reads correctly.