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Midi Controlled Lights

Discussion in 'The Projects Forum' started by supermechacow, Nov 17, 2007.

  1. supermechacow

    Thread Starter New Member

    Nov 17, 2007
    I'm not sure if this is an appropriate place for this, but with a limited amount of knowledge on MIDI, the research is getting frustrating.

    I'm looking for a unit that controls a strobe light through MIDI. Obviously the on/off off the notes triggers the light, and if possible, the velocity could control the intensity (but that's more of an luxury. not really needed). I need to be able to hit long notes (which leaves the light completely on for the duration of the note) and and minute notes which would make a quick flash.

    I'm trying to beatmatch 2-8 strobe lights, essentially, having them play out of that unit versus the rest of the sound. I'll most likely be running a MIDI out from my PC and control it from a MIDI editor or FL Studio, if you're familiar with that.

    I've seen many units like this already, I just can't read the specs to see if that's what I really need or not.

    If anyone could point me to a unit, the unit schematics, or both, I'd be very appreciative.
  2. GS3

    AAC Fanatic!

    Sep 21, 2007
    I'm not sure I understand. A ON note will turn what light on? Depending on what note it is? Frequency? Instrument? It seems to me this is much more of a software project than hardware. Probably well suited for a PIC project. The PIC could interpret the MIDI orders and then control relays (or SCRs).
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    Working directly from a MIDI file (if I have understood properly) would require a DSP chip and a fair amount of custom logic. Most color organs use bandpass filters that divide the total analog signal into regions (bass, midrange, treble) and control the lights based on the filter outputs. Unless you can write the control code for the DSP chip, the analog bandpass filters are probably easier to attempt. The analog signal does not have to be running an amp to be used.

    There are many light organ circuits online. Many have the ability to scale up the outputs to suit the number of controlled lights. Strobe triggers should be fairly easy.
  4. supermechacow

    Thread Starter New Member

    Nov 17, 2007
    It's like this. A MIDI signal is sent to this unit. Depending upon which note you play (C,C#,D, etc.), it runs it to a certain light attached to the unit. The MIDI note ON will turn on the strobe light and hold the light on until the MIDI note OFF. The velocity of the MIDI note affects the intensity of the light, but like I said, that's not really necessary.

    Essentially, I can program notes in my composing software, and set the MIDI out for that channel/track to run to that unit. I can flicker it with a series of quick notes, or hold it longer with long notes.

    I'm trying to avoid analog as much as possible. All of my music is digital already, and trying to mix the two can be a bit more challenging than it's worth to have flashing lights.

    I think this is the closest thing to what I'm trying to explain: http://tomscarff.tripod.com/midi_light/midi_light_controller.htm
    I'm just not having much luck contacting the guy yet.

    Did that help any?
  5. GS3

    AAC Fanatic!

    Sep 21, 2007
    Well, that's pretty much what I had in mind. You'll save a ton of work if you can get it from him rather than develop the thing yourself all over again.
  6. FredM

    Senior Member

    Dec 27, 2005
    If you have a pre-defined set of MIDI commands and channel, this could be extremely simple.. for example, assume CH9 and MIDI note numbers 1 to N (number of lights).. Simple processor (PIC or PSoC) with uart RX, simple decoding of MIDI Note on/off messages, simple driving of port pins in response to incoming MIDI..
    You would need to take the port outputs to whatever driver you require.
    Level control is more complex.. but not impossible.. If you are driving a Triac, you would need a mains zero-crossing detector feeding the MPU, and adjust the firing angle in response to the velocity.
    1.) How many lights?
    2.) What drive do you plan for the lights?
    I use PSoCs and could knock the basics (processor configuration + software) together in about 2 hours.. I am willing to do this for you FOC if you are not in a hurry..