MIDI Drum Machine Project

A friend, Rod Seely, both a musician and electronics hobbiest suggested I design something using the Musical Instrument Device Interface, MIDI, that would be COOL and would work together with his collection of MIDI keyboards and synthesizers. Of course, I wanted to build something that could end up as a finished commercial product.

The project began with the MIDI interface, which we knew very little about, but had to use. After several weeks of late nights spent trying to understand the detail of the MIDI spec, tinkering with circuits, writing 8051 assembly code, reverse engineering electronic musical instruments, and some very nice carpentry and painting on Rod's part, the end result was the finished unit shown here.

Shortly after it was finished, it was played by two experienced drummers, both of whom felt it had the "speed" and a set of features they'd expect from an expensive "professional" electronic instrument.

Content Currently Available

• Feature Set Description - What does it do, what doesn't it do
• A Look Under the Hood - What's inside this thing
• Close Up Look at the Main Circuit Board
• Main Circuit Board Layout
• Main CPU Schematic Diagram
• Simplified Analog Input Schematic Diagram - with explaintion of how it works
• Complete Analog Input Schematic Diagram
• Power Supply Schematic Diagram
• MIDI Port Schematic Diagram
• Front Panel Schematic Diagram (link to front board artwork)
• Internal Wiring Diagram (not available, need to draw nicely)
• Firmware Source Code, Download or On-Line Browse
• MIDI Protocol Details