Mbira said:
There must be a way to do this without having to run through a midi/dmx converter->dimmer pack->lights.
Continuing on the '
trigger a dummy sound in parallel'-route I described above, how about making those dummy-samples distinct sinewave frequencies ?
Send them all out from an unused
single audio-output from the computer (let's assume that's possible, otherwise add the cheapest USB-audio-I/O). Sinewaves can be one-shot triggered samples having the duration as required.
Make those different frequencies cover the full freq-range of your audio-I/O.
For NINE indicators for instance 60 Hz, 120, 240, 480, 960, 1920, 3840, 7680, 15360 Hz
(taking into account bandwidth-limitations of your audio-I/O, and/or shift if you expect massive mains-interference etc)
Using bandpass-filtering in front of a simple LED-clip-stage (say little more than one transistor & LED & some R & C) you can discern between the frequencies. Adjust the sample-levels to finetune. Simple passive filtering might work, otherwise you might need to add one transistor for making it an active bandpassfilter in front of the usual clip-LED-stage.
This should be pretty simple and have low parts count per LED-indicator:
- one or two BJTs
- one diode
- some resistors & caps
If it works well enough you might want too squeeze in more frequencies. And using an audio-interface running at 96kHz sample frequency instantly doubles your amount of possible indicators while maintaining filter-spacing.
If you go the route of making the bandpass filters pretty sharp (say a twin-T in the feedback of an amplif-stage) then note you can finetune the circuit-response by adjusting the sinewave-frequencies to the actually realized filter-frequency (the top). So keep the circuit with its tolerances like it is and adjust at the sinewave-generation side.
Bye,
Peter