Support for active-low buzzer logic

[thankthemaker]

The current implementation uses active-high logic which needs a NPN transistor.
Enhance the firmware to also support active-low logic for PNP transistors

[kp128]

Hello. Can you tell me what part of the code needs to be changed for the buzzer to work on an NPN transistor? The option via a PNP transistor just doesn’t suit me.

[thankthemaker]

Hello,
I haven't used an active buzzer yet, but I guess the wiring needs to be setup different and the Melody-Library needs to be instantiated in a different manner. See
https://github.com/thankthemaker/rESCue/blob/master/src/Buzzer.cpp
and
https://github.com/fabianoriccardi/melody-player
for details.