Dec 162011


Converts between MIDI, DMX, RS-232 Serial and IR

The DecaBox Universal Protocol Bridge - Click to Enlarge

This new firmware revision is an extension of the custom work we did for controlling Jands lighting consoles.  That firmware receives MIDI Show Control messages, then repackages them as RS232 serial strings, which Jands hardware can use for cue triggering.

But now, it’s even more flexible.

Some of our customers were using QLab as a show control platform.  However, they needed to control some RS232 equipment, which QLab doesn’t support.  Since the DecaBox contains an internal SD memory card socket, it made sense to design firmware which could read a simple text file called ‘patch.txt’ from the memory card. This file allows arbitrary serial strings (up to 40 characters in length, each) to be assigned to any MIDI note on, note off or program change message.

System baud rate can be globally set to any standard speed.

Et voilà!  Any serial device can be triggered by MIDI messages.

Here’s how the patch file looks:

; Since this is a command to be parsed, there is no semicolon at the
; beginning of the line.
; Define the MIDI address that the notes will
; be sent from.  MIDI notes received on other channels will be ignored
; Valid range here is [1 16].
; Here's we've set the MIDI channel to 2
; Next, define a baud rate.  No commas needed: 9600 19200 38400 etc
; Note On messages start with N.  Note Off messages start with F.  Program
; change messages start with P.  Hex characters (anything non-printing)
; can be inserted using the $ sign, then a two-digit hex value
; IE carriage return is $0D.  If a $ needs to be generated
; as part of an actual transmitted string, encode it simply as hex $23.
; Google 'ASCII Table' for several handy charts
; Example cue for note 0 [MIDI notes range from 0 to 127] ON
; It's Hello World followed by a carriage return
; N0 Hello World$13
; Note Off Example
; F10 Go Pyro Finale!
; Program Change
; P3 Go Cue 12.34.56$13
; And here's our actual live cue list:
N0 Go Cue 1$13
N1 Go Cue 2$13
N2 Go Cue 3$13
F0 Stop Cue 1$13
F2 Go Cue$13
P8 Someone Hit Program Change #8!!$13

If you need this or similar functionality as part of your system, just let us know.

 Posted by at 11:05 am

  2 Responses to “DecaBox MIDI to RS232 (Field Programmable!)”

  1. Does this unit support USB MIDI or just DIN?

  2. Thanks for your note, Brad. Currently MIDI in and out happen via the DIN jacks. The USB port is only used for firmware updates.

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