see the other side

This is the "brains" of MIDI keyboard. It can be powered from 3 AA cells or external power source (3-5V). It is only scanner and needs external diode matrix to connect to the keys. Matrix is 8x4, see schematic for details.
You can obtain add-on matrix board. It fits directly into 12-pin connector and can be secured by tie-wrap. 2 flat cables connect bare keys' contacts to the add-on board.

Features:

• translates 31 or 32 switches connected in 8x4 diode matrix into MIDI note messages
• optional "channel coupling" - ability to send one note on 2 different MIDI channels. When 32nd key is pressed, all activity on the keyboard is duplicated on additional MIDI channel. Using on-board buttons you can set transposition, and channel number of those duplicated messages. This feature is usefull in pedal boards for church organ emulators.
• unlimited transpoze up/down, i.e. it wraps around when transpozed over 0-127 MIDI note range using 2 small pushbutton on the board.
• MIDI channel change by means of 2 small pushbutton on the board.
• pannel mount metal-cased DIN5 MIDI socket and battery holder, as shown here
• auto power off to save battery (current consumption drops to 10% of normal value after several minutes when not in use, and turns off after 2 hours consuming only about 5uA then).
• it can be used with diode matrix board if pedals don't have hat already.
• long PCBs for housing reed switches in pedal board are awailable for this board too. See it here and here
• dimensions" 43x35mm (1.67''x1.36'')
• more marketing talk

Download user guide for version without coupling

How to order

The board is not available anymore. Instead, smaller board with more features is available now. Please take a look at PEDSCAN board.
Email for details if for any reason you'd like to get the MIDI4B board anyway.