The Tap-Tempo Metronome is a tap-controlled or tap-tempo metronome and
"beat looper." "Syncopation machine." "Metronome with an attitude."
You tap the piezo speaker to set the rhythm. The display shows the
beats per minute, and the two buttons adjust the speed.
"Ehhh." "Boring," you say. Not so fast!
You can tap patterns into it, currently up to 12 beats long. As long
as you tap the pattern in three times, it jumps in and continues
beeping in that rhythm. If you hold one of the buttons while turning
the metronome on, the pitch of the beep will be higher or lower, so
you can play with more than one at a time.
* Easy to assemble kit makes for a great learning experience. All
parts are easy-to-solder through-hole, with no tiny surface mount
* Fully open-source design means that everything is freely available
and ready to be hacked, including the circuit schematic, PCB layout,
part list, and microcontroller firmware.
* Piezoelectric speaker is used as the pattern input, by simply
tapping in the tempo or pattern. Once the metronome learns your
pattern, it starts beeping with the same piezo element.
* Seven-segment displays provide feedback in the form of
beats-per-minute (BPM) readings.
* Custom, professionally-made PCB provides a solid base for happy
tappers. All circuit connections are routed on two layers without the
use of vias, reducing confusion while assembling.
* A Pre-programmed Microcontroller means you don't need a
specialized microcontroller programmer to get started with the
Tap-Tempo Metronome. If you want to experiment with modifying the
firmware, an in-circuit serial programming (ICSP) header is provided
to enable easy re-programming.
* Build Instructions 
* Parts List 
* Download Design and Firmware 
* Design Information