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49+49 Note MIDI Harmonéon

 

MIDI 49 + 49 Switch Inputs Harmonéon

This is a design for a modified MIDI 98 (49+49) input switch Harmonéon. Some of the advantages of such an instrument are the ability to play various types of instrument sounds via MIDI.

 The harmonéon is a musical instrument invented in 1948, or in 1950 by Pierre Monichon and has been taught in French conservatories since 1974.

 

The modified MIDI Harmonéon encoder is capable of encoding the required 98 momentary action, push to make, single pole single throw (SPST) switches to produce the equivalent MIDI note-on/note-off data commands. 

  

The design is based on a two sided  keyboard with 49 keys for the Left hand and 49 keys for the Right hand. 

 

The Treble Right Hand hand is from E1 (MIDI Note Number 28) to E5 (MIDI note number 76) which is 49 Button switches, from switch SW50 to SW98, on MIDI Channel 1.

 

The Bass Left Hand is from Bb1 (MIDI note number 34) to Bb5 (MIDI Note Number 82) which is 49 Button switches, from switch SW1 to SW49, on MIDI Channel 1.

 

 


 

  

 

 

MIDI HARMONÉON 49+49

ITEM#: MIDIHARMONEON49+49

PRICE:  €75.00


 

       *Click to Enlarge*

  


  

The Modified Harmonéon Encoder to MIDI Unit provides:

  • An Arduino Mega 2560 board with a suitable pre-programmed microcontroller,
  • 49 Switch inputs for the Left Hand arranged in a 6x9 matrix and sending MIDI Out on Channel 1,
  • 49 Switch inputs for the Right Hand arranged in a 6x9 matrix and sending MIDI Out on Channel 1, 
  • 2 momentary action switch inputs for Octave +1, +2 and Octave -1, -2, for the Left Hand,
  • 2 momentary action switch inputs for Octave +1, +2 and Octave -1, -2, for the Right Hand,
  • The velocity byte is preset a value of 100,
  • A 2.1mm power socket, and associated LED, 
  • A 150mm wired MIDI 5-pin DIN output socket,
 

 

  

The Modified Harmonéon Encoder to MIDI Unit requires:

  • A 9v battery or equivalent DC power source,
  • Required 98 external switches and associated diodes,  
  • 4 momentary action switches for Octave +2 and Octave -2, for Left and Right Hands,
 

 

Circuit Schematic and Layout Drawings:

 

Hall Effect Wiring:

Note: Use Unipolar Hall Effect devices.

 

  

 

 


 

        

 

Octave Switching:

There are four switch inputs for Octave change switching. There are 2 momentary action switch inputs for Octave +1, +2 and Octave -1, -2, for the Left Hand, and 2 momentary action switch inputs for Octave +1, +2 and Octave -1, -2, for the Right Hand.

  

MIDI Wiring:

The MIDI IN and OUT connections use 5-Pin 180 degree DIN sockets. Note that the MIDI wiring is polarised and the correct pins should be used. 

  

MIDI Harmonéon Wiring:

The switches are organized in two  9 x 6 matrix (but only 49 switches used) arrangement. The switch keys are wired as shown in the  Wiring diagram.

 

One side of the wiring for Switch 1 SW1 for the Left hand is connected to Pin 23 and the other side of SW1 is connected to the Cathode of the diode D1. The Anode of the diode D1 is connected to Pin 22, which is also looped and connected to the Anodes of diodes D7, D13, D19, D26, D31, D37, D43 and D49. Pin 23 is also connected to one side of the switches SW2, SW3, SW4, SW5 and SW6. The other switches and diodes are connected in a similar manner.

 

Also the arrangement of the switches for the Right hand is similar. However note that the physical layout of the actual notes on the Right hand are in reverse physical tuning order. So the Bass Left Hand is from Bb1 (MIDI note number 34) to Bb5 (MIDI Note Number 82) which is 49 Button switches, from switch SW50 to SW98, on MIDI Channel 1. This can be wired as you require just reverse the switch labels. For example Bb1 (MIDI note number 34) is switch label SW50 and continue to Bb5 (MIDI Note Number 82) which is switch label SW98.

 

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.