hey am trying to sample an analog input with an Uno but having problems.
basically A0 is drawing ridiculous amounts of current, and I don't know why. all the other analog inputs are fine, its just A0.
what could cause this? I have a 5V zener on the output to stop it going over-voltage, but I did notice it spiking to 10v when i turn the power supply to my circuit on (which was weird). could transient voltage spikes cause it to do this?