I'm working on a game that's basically a knock sensor. I have a sensor inside a hard plastic bottle, and I need to detect when that bottle is struck hard with a metal rod. And it shouldn't be triggered when adjacent bottles are struck.
Currently I'm doing that by placing one of these inside each bottle:
That has 3 different types of outputs, but I'm currently using the "audio" output, wired straight to one of the Arduino's analog inputs.
It often works very well, but sometimes the knock is completely ignored, and sometimes very soft knocks, or knocks nearby, are registered. I can't figure out the pattern, but its not very reliable.
Can anyone think of anything to make this more reliable? A resistor between the analog and + maybe?
Or maybe another way to approach this entirely?
Thanks for any help.