manitou
Senior Member+
If you're referring to Paul's circuit for the piezo, the diode to 3v3 is used "clamp" the voltage from the piezo to < 4 volts, preventing damage to the teensy analog port.I don't understand the connection to the 3v positive from board, all the examples I've seen are just analog inputs and gnd.
the monitor output attachment in your post #75 is NOT from the sketch in post #23????? the sketch in post #23 prints two columns of numbers, DAC output and A0 input.