db-synth

MIDI implementation

db-synth is a MIDI receiver. It does not transmit any MIDI messages. The MIDI input includes hardware thru, where received bytes are retransmitted to the MIDI OUT/THRU connector, allowing multiple devices to be chained.

Implementation chart

Function		Transmitted	Recognized	Remarks
Basic Channel	Default	x	1--16	Memorized
	Changed	x	1--16
Mode	Default	x	4	Omni Off, Mono
	Messages	x	x
	Altered	--	--
Note Number		x	0--127
	True Voice	--	0--127
Velocity	Note On	x	o
	Note Off	x	x
After Touch	Key's	x	x
	Channel's	x	x
Pitch Bend		x	x

Control change

CC	Function	Transmitted	Recognized	Values
3	Oscillator waveform	x	o	0--31: Square, 32--63: Sine, 64--95: Triangle, 96--127: Saw
70	ADSR envelope type	x	o	0--63: Exponential (AS3310-style), 64--127: Linear
71	Filter type	x	o	0--41: Off, 42--83: Low pass, 84--127: High pass
72	ADSR release time	x	o	2 ms -- 20 s
73	ADSR attack time	x	o	2 ms -- 20 s
74	Filter cutoff frequency	x	o	20 Hz -- 20 kHz
75	ADSR decay time	x	o	2 ms -- 20 s
79	ADSR sustain level	x	o	0--100%
102	Set MIDI channel	x	o	0--63: No action, 64--127: Set to current message channel
119	Write settings to EEPROM	x	o	0--63: No action, 64--127: Write current settings
120	All Sound Off	x	o
123	All Notes Off	x	o

Note

CC 102 (Set MIDI channel) is the only message processed regardless of the currently configured channel. All other messages are filtered by the active channel.

Other messages

Function		Transmitted	Recognized	Remarks
Program Change		x	x
System Exclusive		x	x
System Common	Song Position	x	x
	Song Select	x	x
	Tune Request	x	x
System Real Time	Clock	x	x
	Commands	x	x
Aux Messages	All Sound Off	x	o	CC 120
	Reset All Controllers	x	x
	Local On/Off	x	x
	All Notes Off	x	o	CC 123
	Active Sensing	x	x
	System Reset	x	x

Legend

Symbol	Meaning
o	Recognized
x	Not recognized / Not transmitted
--	Not applicable