project #6: MDBC16x9
MIDI Drawbar 16*9 Controller

dfm

Description:

This controller is based on Project#4 (MDBC8x9). It supports up to 16 drawbars, each with 9 positions (from 0 to 8). It is dfm and will support custom tables made by your demand. No HEX file will be published here, only pre-programmed chips or ready-made unit can be ordered. Supported custom Controller table should look like this:

Table 1: MIDI Controllers supported
Drawbar #
MIDI Contignuous Controller (CC) #
Controller name
(by General MIDI specification)
1
...
User defined
2
...
User defined
3
...
User defined
4
...
User defined
5
...
User defined
6
...
User defined
7
...
User defined
8
...
User defined
9
...
User defined
10
...
User defined
11
...
User defined
12
...
User defined
13
...
User defined
14
...
User defined
15
...
User defined
16
...
User defined

NOTE: '...' means 'Your Controller numbers here'.


Actually, the standard drawbar set consists of 9 drawbars, each having 9 positions, like well-known Voce drawbar controller:



As far as we have switching drawbars here, we should define drawbar positions mapping over MIDI Control value. Default mapping is shown in Table2. This table also could be re-defined by user demand.

Table 2: Drawbar positions mapping
Drawbar position #
Mapped Controller Value
0(off)
000 ($00)
1
010 ($0A)
2
030 ($1E)
3
045($2D)
4
060 ($3C)
5
078 ($4E)
6
099 ($63)
7
114 ($72)
8
127 ($7F)

Schematic:

Used parts:

U1: PIC16F84. Can be used PIC16C84. The difference is that the first one has Flash memory, and the second has EEPROM memory. There is no difference in way they are used in such designs.
U2: 74LS154 decoder 4:16.
X1: Quartz resonator. Must be 4MHz.
C1,C2: Capacitors 27pF each. Certain quartz resonators have these capacitors integrated. If you use such resonator, there is no need of C1 and C2.
R1,R2: Resistor 3.3 kOhms.
R3: Resistor 270 Ohms.
Diodes: Can be any type of standard diodes.
P1: An DB25 male connector for plugging into PC soundcard Game/MIDI port connector.
bar1..bar16: 9-position sliding switches (drawbar). Rotary switches can also be used.
Embedded software:

The firmware (HEX file) will not be published here. Only pre-programmed chips with this firmware could be ordered. For details see ordering.

Ordering:

The only way to have mdbc16x9 controller supporting Table1 and Table2 defined by you is ordering.
Details about how to order pre-programmed chip or ready made unit can be found here.

 

Hosted by www.Geocities.ws

1