MIDI Data Genenerator User Manual

By Bojan Burkeljc




Note: 
This circuit was only put together once on protoboard to test some 
other project I made way back, so at the time this manual has been 
written I forgot most of the functions of the circuit and I had to 
extract them from the source code (without comments, just to make 
things even worse). I hope I've got them all...
I also apologize for any spelling/grammar errors in the text.


User Interface

User interface consists of 11 buttons and one SPDT switch. Seven of
those buttons are data buttons for data entering, while other
four and a switch are function controls:

Name:		Function
Note		Periodically sends Note On/Off messages while pressed
CC		Periodically sends CC messages while pressed
Sync		Sends Sync Start message when Sync is enabled,
		also sends panic when Note or CC button is pressed
Setup		Setup button 
-----
Sync switch	This enables MIDI clock


Note transmition

When pressing Note function button, the device will trasmit note
on and off messages with the pitch and the velocity set by binary
representation of the data buttons' state (i.e. if there is only
right one pressed, the device will trasmit note with pitch and 
velocity of 1; if all buttons are pressed the pitch will be 127). 
If the Sync button is pressed while Note button is pressed, this
sends CC #123, which should turn all voices off.

The MIDI channel of the note can be set by pressing Setup button
and - while holding it - pressing Note button. This stores the
state of "lower" 4 data buttons as a MIDI channel. It also
stores the state of left data button (if it is pressed, the
Note On message with velocity of 0 is transmitted to terminate
the note instead of normal Note Off message).

Continuous controller transmition

When pressing CC function button, the device will transmit 
continuous controller. The CC value is set by the state of data
buttons.
The CC number is set bit by pressing Setup button and - while 
holding it - pressing CC button. This stores state of data buttons 
as a CC number.

Sync transmition

The device starts transmitting MIDI clock ticks when the Sync 
switch is toggled. When the Sync button is pressed, it will produce
a MIDI clock start message, and when depressed it will produce
stop message.
The clock rate is determined by data buttons and ranges from
1.2 s (cca. 0.5 BPM; when no data button is pressed) to 4.8 ms 
(cca. 130 BPM; when all buttons are pressed).

