New in v1.1
Option to play notes in background, returning control back to your sketch for processing while note plays (similar to the way the tone library works). Volume is now linear and in the range from 0-10. Now uses prescaler 256 instead of 64 for frequencies below 122 Hz so it can go down to 1 Hz no matter what speed the CPU is clocked at (helpful if using toneAC to control a two-pin dual LED).
Download:
toneAC v1.1
Tim