This is one-board solution for typical organ console MIDI controllers. It scans 3 keyboards: 2 x 64-keys, and one pedalboard with 37 keys. It can be powered from 3 AA cells or external power source (4-5V). Current consumption is about 1mA. Scanned keys must be grouped by 16, i.e. one pole of each of 16 keys in a row connected together, other poles go to their corresponding pin on IDC connector, so 17 wires from the board go for each group of 16 keys. Each keyboards is connected using 2 IDC headers with 34 pins, while pedal board uses 40-pin IDC. Additional small 7-pin header is used for potentiometers an transposition.

board layout

34-pin connector diagram

40-pin connector diagram

See also another option for connecting multiple (up to 6) keyboards.

Features:

• 3 keyboards, more than 13 octaves total, each keyboard sends note messages in different MIDI channel
• unlimited transpoze up/down independent for each keyboard.
• transposition settings stored in nonvolatile memmory.
• keyboard coupling - generate notes in multiple keyboards with single key stroke
• cable with pannel mount metal-cased DIN5 MIDI socket
• one CC for each keyboard, e.g. channel volume.
• more marketing talk
• dimensions 122x57mm (4.8''x2.25'')

How to order

The board is available for 100EUR including shipping worldwide. When placing order, you choose:

1. keyboard range, i.e. what are the note numbers assigned to each key. They don't have to be continuous, and can also duplicate. Transposition moves all keys up and down in 1-semitone steps. Usually keyboards start at MIDI note #36
2. MIDI channel of each 3 keyboards. This cannot be changed later. One keyboard cannot be split to send messages on 2 channels, but all 3 can share same channel.
3. how many (1, 2, 3 or none) controllers will be used, and what they should be. Channel volume for each keyboard is only a example. CC type cannot be changed later