Greg Lewin Music

Organ Projects.

9 Westgate, Bridgnorth, Shropshire, WV16 5BL
Tel.: 07718 082150; Email:

Pedal Board Conversion.

This pedal board was acquired and converted as part of a small Hauptwerk based organ built to fill-in for a pipe organ which was undergoing repair and modernisation. The board, purchased on Ebay, was said by the vendor to have come from an organ by Hill. The donor organ was probably tracker action - the board still had its roller board attached. It is a 30 note board of the standard radiating and concave type.

As purchased, the pedal board had no electronics to provide a MIDI output. I considered several methods of adding this. I had previously MIDIfied a pedal board using reed switches - which worked well but which was tricky to set up; I had a set of Kimber Allen wire contacts but these are said to be troublesome at the 5 volt level required by the electronics I had in mind. After some thought I decided to modify the photo-interrupter method which I have used successfully on several keyboard MIDIfications. The space on the pedal board once occupied by the roller board provided a convenient spot to mount the electronics.

The photograph above shows the circuit boards being tested. They are mounted on the back of the toe rail.

Here you can see a part of the circuit mounted back on the pedal board. The black plastic shutters can be seen in place between the arms of the photo-interrupter units. When a pedal is played the shutters move out from between the photo-diode and the detector and switch the note on. This system has proved to be very reliable on keyboards and appears to work just as well here.

The switch signals are processed by an Arduino Uno microprocessor fitted with a shield which connects to the photo-interrupters and which also provides a socket for MIDI OUT. The processor is fixed to the back of a board made to cover the electronics space. A socket board allows easy connection to MIDI and a 9 volt power supply.

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Page maintained by Greg Lewin
25th November 2019