I wanted to use a piezo sounder to sound an alarm in an application. Testing indicated that
tone() was not very loud.
I could use some external circuitry to swing the pins ±5V but as I have plenty of spare pins, it seemed feasible to use 2 pins driven in anti-phase to increase the power by 4.
I looked at the source
Tone.cpp but the code is somewhat intimidating. Before I start to modify it I was wondering if anyone else has already done something like this.