- Arduino Uno
I'm trying to use my only two remaining pins, either Digital 0 or Digital 1 (rx and tx for serial too, I know) to drive a small piezo speaker. But as soon as it's connected and the moment the Uno receives power, the speaker starts making a very high pitched tone, one constant tone. Higher pitched for D1 than D0.
All the other pins are occupied by this 2.4" TFT LCD touchscreen:
My code does not have any Serial. statements in it, I am not engaging the serial interface.
I am including these libraries:
But I searched through them and they ALSO do not have any Serial. statements. As far as I can tell no part of my code is using the serial interface, so why does my speaker make a high pitched tone when it's connected to D0 or D1?