MIDI Melodeon The MIDI Melodeon encoder is capable of encoding the required momentary action, push to make, single pole single throw (SPST) switches to produce the equivalent MIDI note-on/note-off data commands. The design consists of the MIDI Melodeon circuit  and the encoded switches wired via IN4148 diodes, see switches circuit diagram. The design is based on a two row diatonic keyboard with 10+11 keys for the right hand and 8 keys for the left hand. This design is for a melodeon in  G/C keys, G/D keys, and  in B/C keys but other keys could be encoded if required.       MIDI MELODEON G/C ITEM#: MIDIMELGC PRICE:  €35.00 MIDI MELODEON G/D ITEM#: MIDIMELGD PRICE:  €35.00 MIDI MELODEON B/C ITEM#: MIDIMELBC PRICE:  €35.00         The Melodeon Encoder to MIDI Unit utilizes: The MIDI channel is set to channel 1 for right hand 10 + 11 switches, The MIDI channel is set to channel 2 for the Bass and channel 3 for the associated Chord for left hand 8 switches, The velocity byte is preset to the maximum value. A wiring layout for the circuit is also available. A Miduino kit including a suitable pre-programmed Atmega168, A 2.1mm power socket, and associated LED,  A MIDI 5-pin DIN input socket, A MIDI 5-pin DIN output socket, The circuit schematic is available,        The Melodeon Encoder to MIDI Unit requires:   A 9v battery or equivalent DC power source Required 29 external switches and associated diodes A switch to operate the melodeon in push/pull modes

Circuit Schematic:

A circuit schematic of the Miduino Melodeon shows the switch connections. Note that for this project the 4-way DIL switch is not required. The circuit schematic for the MIDI Melodeon switches, and a wiring diagram  are also available.

Assembly:

The kit includes all parts necessary, the assembly is straightforward and well documented. This design does not include a USB chip, it is designed to use a FTDI USB 232-TTL cable to program the microcontroller.  However since the cable plugs directly into the Miduino, you can use one cable for multiple Miduinos.

MIDI Wiring:

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

MIDI Channels:

Operation:

The Push/Pull switch can be mounted at the rear of the unit and operated by the left or right thumb. It is designed so that when pushing the melodeon the Push/Pull switch should be pushed also. Whereas when the melodeon is pulled the Push/Pull switch is released. Alternatively a foot-pedal switch could be used if desired.