In this video we finally give the Lunchbeat a chance to play some phat tunes. Something isn’t quite right, though. If you guessed that it isn’t using the external crystal and is instead running from the internal clock source, you’d be correct! :D

I had the right idea about using the internal clock, but it is an RC oscillator rather than a crystal. Close in spirit, wrong in silicon. With the ATmega328P’s factory clock settings, the 8 MHz oscillator is divided by eight to give a 1 MHz system clock. That could explain why everything sounds a little… relaxed.

The external 16 MHz crystal gets its turn in the next sound demo.

Sources

Lunchbeat / PICkit 2 series