scanners, all user inputs are bare pads to solder wires. This further reduces space
required for installation, because typical IDC headers would be too big. Of course it
may work in any other instrument/controller requiring limited (24) number of
contacts, and up to 3 potentiometers. The diagram below describes all connections
to BBS24.
7.6
LITSW - button scanner with LED drivers
LITSW is the controller for lighted switches. It has 24 inputs for contacts, and 24
outputs for LEDs associated with them. Currently available modes of operation for
this board are:
1. independent registers ("check boxes"), where each button click lights up or
darkens the LED, and proper MIDI message is generated according to MBBS
setting for that scanner. If this is MIDI note, a note-on is generated at LED
turn-on and note-off when LED turns off. If it is Program Change, only one
event is generated, when the LED turns on
2. dependent choice ("radio buttons"), where only one LED-button can be
active (lights up). Pressing any other button causes previously lighted to turn
off, and the one pressed lights up now. If assigned to notes, only MIDI note-
on is generated, this is more suitable for use with Program Change
3. contact on/off mode, where button action is recognized as typical contact
scanner (BBS). So all kinds of MIDI events applicable to a keyboard are also
possible here giving predictive results.
4. CC value mode, where LITSW works like potentiometer scanner, but with
only min and max values. The advantage of this mode is that you can assign
totaly different MIDI channel and event to each button.
5. bank/select, useful for preset selectors. In this mode LITSW must be split in
2 parts. One is serving as bank select, the other one - as program select. If
the split is made on 10th key, lower split is representing units of given
Program number, and the upper one - tens of this number. Of course it
makes more sense when MIDI event 129 is assigned to that LITSW (that's
Program Change)
It is possible to select more than one mode at once, although not always it makes
sense. For example modes 1-2, as well as 3-4 are mutually exclusive, but you can
set for example modes 1, 3 and 5 together. The mode of operation can be assigned
to all buttons or differently to each of the 2 splits if it was divided (chapter 7.6.1.)
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