This project is creating DR-55 MIDI sync board.
BOSS DR-55, Dr. Rhythm, is a programable rhythm machine manuafactured by Roland in 1979. This projects brings MIDI conenectibity to DR-55. This project includes schematics and sketch for Arduino.
Watch demo movie at YouTube
DR-55 sync to the MIDI clock from external rhythm machine or sequencer.
You can play DR-55 manualy from external keyboard or sequencer by MIDI note message. Hi-hat supports variation of open/close/pedal.
When the velocity value is larger than threshold, accent signal turn on. Threshold value is defined in source code.
Receive MIDI channel is 10 in default. While the switch sets on, every midi channel is recognized. Receive channel is specified in the source code.
Receive Messages
Channel Messages
Note Message 9x nn vv (Hex)
x … midi channel
1-16 : When the Omni switch is on
10 : When the Omni switch is off
nn … note number
48 = BD
50, 52 = SD
51 = RS
54 = Close HH
56 = Pedal HH
58 = Open HH
vv …velocity
0 : no sound
1 - 89 : sound without accent
90 - 127 : sound with accent
Threshold is specified in source code.
System Real Time Messages
MIDI Clock F8 (Hex)
Start FA (Hex)
Stop FC (Hex)Using Arduino Pro Mini compatible board (5V 16MHz)
Power is provided from DR-55.
The board is connected to DR-55 with 10 core flat cable. Board side of the cable is connector. DR-55 side of cable should be soldered to the DR-55 main board directory. No additional parts or special modification is required in DR-55 side. Please refer Connection Guide in the repository for detail.
Switch 1 of the DIP SW is a program switch of Arduino. Switch 2 - 4 can be used any setting.
The sketch uses Metro library as timers.
Configuration of PCB version is place at the top of the sketch. It assign the io pins. If you use PCB provided from my project, define the appropriate version.
Please refer this document.
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