MIDI -> Trigger interface

[ma3a.au]

g'day everybody. apart from building the SEQ (will start that in a month or two, when i have more time, and more experience with soldering :P) and modifying the magic delay code for my needs, there's one other thing i'd like to do with the MIDIbox project: build a MIDI to trigger interface.

i'm not sure if someone else has already talked about this, or maybe even done it; i haven't been able to find any info in the forums. people seem to be more interested in making trigger to MIDI interfaces, but i'd like it the other way around :).

the reason i'd like to build one is that it'd enable me to control, through MIDI,  the older, cheaper drum machines with only simple modification (for each sound - and perhaps its accent - to be triggered when voltage is applied to an input; this is how the older drum machines' sequencers worked, anyway, so it's not hard at all), and also because it'd allow me to control home-built stuff...and lights and electric kettles etc, if i ever feel the need ;).

anyway! i don't need analog control; just an "on" or "off" is fine (i.e.  a quick voltage spike to let the trigger-input of the drum machine know it has to do something), so i'd be using DOUTX4 modules. what i envisage is:

* 16 trigger-outs

* five switches;

    ** the first switch will choose whether to take the each trigger's trigger from MIDI input from 16 consecutive notes on a particular channel (these notes will be more or less 'hard-wired'; not user-definable. i want to keep this simple!), or whether to take each trigger-out's trigger from any note on its corresponding MIDI channel (channel 1 triggers trigger-out 1, etc). sorry if i didn't word that very well.

    ** the last four switches will be to determine the MIDI channel number to take the input of notes from, if the first switch is set to take its input from 16 consecutive notes on one channel. if the first switch is set to take each trigger's input from its corresponding MIDI channel, then the four channel switches will have no effect.

* in a rack-mount case

it seems pretty simple to me, and i think i could program it, given some time. i'm not so sure about the hardware-side (specifically whether the voltage from the DOUT modules would be enough, or whether they'd have to be in a transistor setup to trigger larger voltages, and also what voltages would work with most drum machines etc while not damaging them - 5V?), so my questions are:

* has this been done before by anyone, to spare me some effort..?

* does anybody have any ideas how i could make this work (both on the hardware and software side; is there a particular route or method that i should take in writing the software?)? it'd be an incredibly useful device in my line of music/experimentation :)

sorry this is fairly long and not written in a very interesting way. i look forward to your replies! :D

-duncan