SOLVED Buzzer - AC or DC?
mh last edited by mh
The firmware code seems to assume that the buzzer is a piezo sounder that needs to be driven with the frequency at which it should beep ("Resonant frequency of the piezo sounder is 4.5kHz.")
However at least on PanelDue V3 I only see parts that seem to be DC buzzers with their own oscillator (with a little "+" mark on the housing).
Did the type of buzzer change over time / versions?
The buzzer on PanelDue is and always has been a piezo sounder that needs to be driven by AC. It can be driven at any audible frequency, but it is loudest when driven near its resonant frequency.
mh last edited by
Thanks for the clarification!
Indeed when having a closer look at an original PCB, the little mark is an "S", not a "+". I guess I got confused by looking at some pictures in a web search, which showed cloned PCBs.