Beat707 is an Arduino Shield that adds several neat features to your musical arsenal. You get a 32 step machine, with 16 step buttons and leds, LCD screen and navigation keys. Its like the classic Roland TR707 but with some twists, as it actually has 32 x 1/32 or 32 x 1/64 steps. Plus, the 2 note-step sequence feature allows you to do bass and/or synth lines -- it's a MIDI groove-box all in one ! The unit doesn't produce any sound, its all MIDI based, so you can use any MIDI compatible device.
Watch the Videos: http://www.beat707.com/w/videos
This project is a joint collaboration between Wusik.com and Rugged Circuits. We've made a proper Arduino shield that plugs in on top of an Arduino Uno, Duemilanove, or Mega/Mega2560 (not included). The software performs all the drum machine functions, but you can always tweak it to do whatever you want (with the source code reward levels). We've added EEPROM, FLASH, and expandability options and connectors.
And it's not just a drum machine: the hardware is a general-purpose MIDI development platform and playground. The awesome software from Wusik.com is what provides the drum machine functionality, but you can run any software you want on your Arduino to make use of the hardware.