Hi all,
For several months now I’ve been thinking about doing a DIY MIDIBox to replicate an expensive and hard to find accessory for my Roland VS2400 audio workstation - the Roland MB-24 meter bridge.
The meter bridge is driven off MIDI data sent on channel 16. Roland rather conveniently published the actual MIDI spec used to drive the MB-24 in the back of one of their manuals (which I’ve inserted at the end of this post).
The MB-24 was originally designed for use with the V7200 digital mixing platform, so there are some features and functions that don’t get used when connected (some of the section light, and the 9th and 10th digit in the scene/timecode display). What is required is about 370 LEDs and 8 7-seq displays ie. around 420 digital out controls.
Hardware-wise, I see myself needing:
1 core unit
2 DOUTx4 units for the meters and status lights… each board can control 256 LEDs in a 16x16 scan-switching arrangement. 2 will easily cover all the meter groups and other status lights.
1 DOUTx4 unit for the MTC/LED display output (actually only need 3/4s of it).
Sound right?
Software wise, I’m not really sure where to start. This would be my first foray into MIOS and assembler… I’ve done some PICAXE dev before, but I realise there’s some serious work ahead. I suppose what I’m asking for are some ideas and examples of where to start.
The other thing I’m worried about is the speed at which MIOS and the DOUT units can refresh the matrix of LEDs… ideally I’d want the LEDs to run at 15-25fps without any noticeable scanning or interlacing. Can the OS process data that fast?
Would love to hear anyone’s thoughts and ideas.
Cheers, Ben.
ROLAND VS-2400 - output spec for MB-24 Meter Bridge
[tt]Transmits the level meter value of VS-2400CD according to the value of DISPLAY SECTION (MIDI ch. is fixed to 16.)
Ignored when received.
Status Second Third
------ ------ -----
AFH mmH llH
mm = Note No. : 00H - 5BH (0 - 91)
ll = Level Meter Value : 00H - 7FH (0 - 127)
Level meter and NOTE No.
Level Meter Analog Digital Input Track FX AUX/ Analog Digital
Target Input Input Mixer Mixer Return DIR Output Output
Note Level Level Level Level Level Level Level Level
Meter Meter Meter Meter Meter Meter Meter Meter
Number Channel Channel Channel Channel Channel Channel Channel Channel
0 Input 1 R-BUS 1 Input 1 Track 1 FxRtn 1L AUX 1 Output 1 R-BUS 1
1 Input 2 R-BUS 2 Input 2 Track 2 FxRtn 1R AUX 2 Output 2 R-BUS 2
2 Input 3 R-BUS 3 Input 3 Track 3 FxRtn 2L AUX 3 Output 3 R-BUS 3
3 Input 4 R-BUS 4 Input 4 Track 4 FxRtn 2R AUX 4 Output 4 R-BUS 4
4 Input 5 R-BUS 5 Input 5 Track 5 FxRtn 3L AUX 5 Output 5 R-BUS 5
5 Input 6 R-BUS 6 Input 6 Track 6 FxRtn 3R AUX 6 Output 6 R-BUS 6
6 Input 7 R-BUS 7 Input 7 Track 7 FxRtn 4L AUX 7 Output 7 R-BUS 7
7 Input 8 R-BUS 8 Input 8 Track 8 FxRtn 4R AUX 8 Output 8 R-BUS 8
8 - - Input 9 Track 9 - DIR 1 - -
9 - - Input 10 Track 10 - DIR 2 - -
10 - - Input 11 Track 11 - DIR 3 - -
11 - - Input 12 Track 12 - DIR 4 - -
12 - - Input 13 Track 13 - DIR 5 - -
13 - - Input 14 Track 14 - DIR 6 - -
14 - - Input 15 Track 15 - DIR 7 - -
15 - - Input 16 Track 16 - DIR 8 - -
16 - D.In L - Track 17 - - - D.Out L
17 - D.In R - Track 18 - - - D.Out R
18 - - - Track 19 - - - -
19 - - - Track 20 - - - -
20 - - - Track 21 - - - -
21 - - - Track 22 - - - -
22 - - - Track 23 - - - -
23 - - - Track 24 - - - -
24 - - - - - - - -
25 - - - - - - - -
26 - - - - - - - -
27 - - - - - - - -
28 - - - - - - - -
29 - - - - - - - -
30 - - - - - - - -
31 - - - - - - - -
32 MONITOR L MONITOR L MONITOR L MONITOR L MONITOR L MONITOR L MONITOR L MONITOR L
33 MONITOR R MONITOR R MONITOR R MONITOR R MONITOR R MONITOR R MONITOR R MONITOR R
34 MASTER L MASTER L MASTER L MASTER L MASTER L MASTER L MASTER L MASTER L
35 MASTER R MASTER R MASTER R MASTER R MASTER R MASTER R MASTER R MASTER R
36
37
38
39
40 Channel Status 1ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
41 Channel Status 2ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
42 Channel Status 3ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
43 Channel Status 4ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
44 Channel Status 5ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
45 Channel Status 6ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
46 Channel Status 7ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
47 Channel Status 8ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
48 Channel Status 9ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
49 Channel Status 10ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
50 Channel Status 11ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
51 Channel Status 12ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
52 Channel Status 13ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
53 Channel Status 14ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
54 Channel Status 15ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
55 Channel Status 16ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
56 Channel Status 17ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
57 Channel Status 18ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
58 Channel Status 19ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
59 Channel Status 20ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
60 Channel Status 21ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
61 Channel Status 22ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
62 Channel Status 23ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
63 Channel Status 24ch 0:Off, 1:Play, 2:Bounce/Source, 3:Rec
64
65
66
67
68
69
70
71
72 SCALE 0:X1, 1:X1/2
73 LOCATION 1:PRE FADER, 2:POST FADER
74
75
76
77
78 8SEG.MODE 0:Measure/Beat, 1:Time Code, 2:Clock+Scene
79 OVER RANGE 0:0db
80 MASTER MUTE 0:OFF, 1:ON
81 PEAK HOLD TIME 0:OFF
82
83
84
85
86
87
88 CLOCK HOUR(*1) / MEAS. MSB (*2)
89 CLOCK MIN.(*1) / MEAS. LSB (*2)
90 CLOCK SEC.(*1) / BEAT (*2)
91 SCENE (*1) / TICK (*2)
92
(*1) When 8SEG.MODE is 2.
(*2) When 8SEG.MODE is 0.
Level Meter Value and Level
Value Level
0 0dB
1 -1dB
2 -2dB
:
127 -Infinite
[/tt]
