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MIDI Accordion 12 Note Bass Switches Unit 



MIDI Accordion 12 Note Bass Switches Unit


The MIDI Accordion 12 Note Bass Switches Unit is capable of encoding 12 momentary action, push to make, single pole single throw (SPST), switches to produce the equivalent MIDI note-on/note-off data commands. The unit transmits on MIDI Channel 1, but other MIDI channels (1 to 16) can be pre-programmed if required.


One side of each of the MIDI Accordion 12 Note Bass Switches are wired to a common Ground (GND) pin and the other side of each switch is wired to a different digital input pin.


The MIDI start Note is set to E2 (MIDI Note 40), which is connected to switch SW1, then the switches follow continuously to the last switch SW12, which is D#3 (MIDI Note 51). But any different start note can be pre-programmed if required. 


This unit can be connected to the Bass switches of an accordion  by using hall effect or magnetic/reed switches, providing a MIDI output.






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PRICE:  €45.00






The MIDI Accordion 12 Note Bass Switches 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 E2 (MIDI Note 40), 
  • The MIDI Channel is preset to channel 1,
  • Other MIDI channel, velocity and start Note can be programmed on request,
  • A 2.1mm power socket, and associated  power-on LED.



The MIDI Accordion 12 Note Bass Switches Unit requires:

  • a 9v battery or equivalent DC power source,
  • Suitable 12  key-switches, hall effect switches or magnetic reed switches,


Circuit Schematic:

A circuit schematic of MIDI Accordion 12 Note Bass Switches Unit shows the switch connections. 







The MIDI Pitch/Frequency Table:




1 D2 40 E 82.41 Hz
2 D3 41 F 87.31 Hz
3 D8 42 F#  92.50 Hz
4 D9 43 G 98.00 Hz
5 D10 44 G#  103.8 Hz
6 D11 45 A  110.0 Hz
7 D12 46 A# 116.54 Hz
8 A0(D14) 47 B 123.47 Hz
9 A1(D15) 48 C 130.81 Hz
10 A2(D16) 49 C# 138.59 Hz
11 A3(D17) 50 D 146.83 Hz
12 A4(D18) 51 D# 155.56 Hz






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.