Connected a piezo sesor with resistor already soldered to it. I am monitoring analodRead() from pin connected to piezo, and when i touch it, bend, it oscilates between 41* and 0 with maximum pressure. Is that how it suppose to work? Isn't value should go up? Tried with both polarities. Board is ArduinoMega 2560, with piezo between GND and A0
Yes that's normal. It's actually oscillating around 0V, but the Arduino can't read below 0V and clamps it to ground.
Ok, it solved itself, even though, A0, turns out, wasn't connected to anything, it still somehow reacted to Piezo on A1. Now A1 reads 0, and goes up after pressure on piezo