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MIDI 6 x 9 (54 keys) matrix Note Keyboard Encoder


MIDI  6 x 9 Matrix Keyboard Encoder 


This keyboard encoder is capable of encoding any number of momentary action, push to make, single pole single throw (SPST), switches from 1 up to 54 to produce the equivalent MIDI note-on/note-off data commands. The keys are arranged in an 6 x 9 (54 keys) matrix. The keyboard ranges from MIDI note 31 (G1) to MIDI note 84 (C6). Other keyboard ranges can be programmed on request.


Note: This design can be used with 49 note keyboards with the unused keys left unconnected.


This design can be used with the Yamaha PSS-480 49 note keyboard, whose  keyboard ranges from MIDI note 36 (C2) to MIDI note 84 (C6).


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



MIDI 6x9 Keyboard


PRICE:  €45.00


 *Click to Enlarge*







The Keyboard 6 x 9 Matrix Encoder to MIDI Unit consists of:


  • The MIDI channel is preset to channel 1 
  • The velocity byte is preset to a value of 100,
  • Keyboard ranges from MIDI note 31 (G1) to MIDI note 84 (C6),
  • Other MIDI channel, velocity and start Note can be programmed on request,
  • An Arduino board including a suitable pre-programmed microcontroller,
  • A 2.1mm power socket, and associated LED, ,
  • A MIDI 5-pin DIN output socket.



The Keyboard 6 x 9 Matrix Encoder to MIDI unit requires:

  • a 9v battery or equivalent DC power source
  • Suitable key-switches or magnetic reed switches and associated IN4148 diodes


Circuit Schematic:

The full 54 switches circuit schematic of the MIDI 54 note keyboard shows the switch connections. A switches circuit schematic of the MIDI 49 note Yamaha PSS-480 keyboard shows the 49 switch connections. Also the Arduino Uno schematic is available. 



The MIDI OUT connector uses a  5-Pin 180 degree DIN socket. Note that the MIDI OUT wiring is polarized and the correct pins should be used.







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.


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.