Build your own MIDI projects
Frequently Asked Questions.
MIDI & Music
MIDI and Music Information



This MIDI Bass Pedal circuit is capable of encoding up to 32 momentary action, push to make, single pole single throw (SPST), switches to produce the equivalent MIDI note-on/note-off data commands. So this design can be used with any 13 to 32 note pedalboards. Any unrequired notes can just be left unconnected. There are also Octave Up and and Octave Down switch inputs.


One side of each of the encoded Bass Pedal switches are wired to a common Ground (GND) pin and the other side of the switches 1 to 32 are wired to the digital input pins 22 to 53, respectively.


The MIDI start Note is set to C2 (MIDI Note 36), which is connected to switch SW1, then the switches follow continuously to the last switch SW32, which is G4 (MIDI Note 67). But any different start note can be pre-programmed if required. 


This unit can be connected to new bass pedals or it can be used with an older non-MIDI bass pedals by using magnetic/reed or Hall Effect switches to isolate the old and new scanning circuits. This will allow the older bass pedal synthesizer to continue to operate as normal while also providing a MIDI output.


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PRICE:  €60.00






The MIDI 32 NOTE BASS PEDAL UNIT consists of:

  • An assembled MIDI Arduino Board, including a suitable pre-programmed microcontroller, 
  • A MIDI 5-pin DIN output socket,
  • The velocity byte is preset to the maximum value,
  • The start Note of the keyboard encoder is preset to C2 (MIDI Note 36), 
  • Octave Up and Octave Down switch inputs,
  • The MIDI Channel is preset to channel 3,
  • Other MIDI channel, velocity and start Note can be programmed on request,
  • A 2.1mm power socket, and associated  power-on LED.




  • a 9v battery or equivalent DC power source,
  • Suitable 32 pedal-board/ key-switches or magnetic reed or Hall Effect switches,
  • Suitable 2 momentary action Octave Up/Down switches.


Circuit Schematic:

A switches circuit schematic of the MIDI Bass Pedal Encoder shows the switch connections. When wiring please note that the 32 pins required are the inner 2x16 pins of the 2x18 way connector. The 4 outer pins are 2 for +5 Volt at one end and 2 for 0 Volt (GND) at the other end.







Power Supply: 

External  power can come either from an AC-to-DC adapter  or battery. The adapter can be connected by plugging a 2.1mm center-positive plug  into the board's power jack. Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER connector.


The board can operate on an external supply of 7 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts.



Pedalboard Sizes:

There are many different sizes of pedalboards available today. But generally pedalboards range in size from 13 notes on small organs designed for in-home use (an octave, conventionally C2–C3) to 32 notes (two and a half octaves, C2–G4) on church or concert organs. Modern pipe organs typically have 30-note or 32-note pedalboards, while some electronic organs and many older pipe organs have 25-note pedalboards.
Exact design specifications for pedalboards are published in Great Britain by the Royal College of Organists (RCO), in the United States by the American Guild of Organists (AGO) (which requires a design similar to the RCO's), and in Germany by the  Bund Deutscher Orgelbaumeister (BDO) (which allows both 30-note and 32-note pedalboards, of both concave/radiating and concave/parallel varieties).


Here is an interesting link to Building a pedalboard.