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MIDI & Music
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MIDI 49 Note 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  49 to produce the equivalent MIDI note-on/note-off data commands. The keys are arranged in an 8 x 7 (56 keys) matrix. The unit also provides Analog Inputs for MIDI Volume and Modulation controls.


The encoded switches are wired via IN4148 diodes, see switches schematic.


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 49 Note Keyboard 


PRICE:  €45.00


 *Click to Enlarge*







The 49 Note Keyboard Encoder to MIDI Unit consists of:


  • The MIDI channel is preset to channel 1 
  • The velocity byte is preset to the maximum value.
  • 49 Note Keyboard ranges from MIDI note 36 (C2) 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,
  • 2 Analog Inputs for MIDI Volume and Modulation controls.



The 49 Note Keyboard Encoder to MIDI unit requires:

  • a 9v battery or equivalent DC power source
  • Suitable key-switches or magnetic reed switches and associated IN4148 diodes,
  • 2 off 10K ohm MIDI Volume and Modulation controls.


Circuit Schematic:

A switches circuit schematic of the MIDI 49 note keyboard shows the switch connections. 


NOTE: The 2 Analog Inputs for MIDI Volume and Modulation controls should be connected to Ground (GND) if unused. Otherwise the inputs will pickup noise and produce random MIDI outputs.



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






MIDI Keyboard Wiring:

The switches are organized in a 8 x 7 matrix (56 switches) arrangement, but only 49 are required for the 49 note keyboard encoder.


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.