This is a little (often annoying) piece of hardware. The original design was posted on PopSci.com back in 2008.

I've refined the schematic and made a board layout in Eagle which you can download below.

• Connect a 9V battery block via the EXTPWR pin header.
• Connect a 8 Ohm speaker via the EXTSPKR pin header.
• By bridging pins 1 and 2 of the AON jumper you can over-ride the switch and have the device 'always on'.
• I didn't invest too much time into finding a suitable push button, so feel free to modify the design with a button of your choosing.

• Schematic
• Layout
• Eagle files (rev2 20100830)

All files released under Creative Commons non-commercial, by attribution, share-alike.

The rev2_20100830 board is not tested. The only live and working setup is a perf-board based system.