Simple color organ

[davisgraveyard]

I have a lightning machine in our display that has a 110v plug and small external microphone with a sensitivity knob.  If I play thunder audio near the box it flickers a 100w flood I have plugged in.    The 2 problems I have with this setup is that the microphone requires that an audio speaker be up close to it which is far away from where the people who need to hear it are.  The other is that the unit is pretty sensitive and there is a fine line between always on and always off with a little flicker in between.

So I was thinking.   Couldn't this be done with a Prop-1 and a RC-4 with 1 relay?  I guess I would still need some sort of audio trigger but I bought a device from simple circuits a while back that has a audio relay switch that triggers another prop with an audio signal? 

Any ideas?

Jeff

[JonnyMac]

You'd want to be very careful with the interface.  An idea: connect the speaker outputs to an opto-isolator (like the H11AA1 that we use on the FC-4 and EZ-8); you'll get a low-going pulse on the output when audio is present.  You'll have to adjust the current limiters on the inputs (maybe with a pot) to adjust sensitivity. 

[davisgraveyard]

What "interface" are you concerned about?

Not familiar with a "opto-isolator" (sorry not a electronics guy just software).  Not sure what you are suggesting?

The circuit I was thinking about using from simplecircuitboards.com  is this one  http://www.simplecircuitboards.com/Spec%20Sheets/Sound%20Activated%20Relay.pdf   I've used it before with a Prop-1 one as a trigger to start a prop.   Is there a way I can interface it directly to a RC-4 and not use the Prop-1?   I don't mind using the Prop-1 one but for this case its going to be a simple 4 line program to wait for a trigger and then send a on/off to the RC-4.

[JonnyMac]

You need to power the RC-4 with 5v... but if the goal is simply turning a light on when sound reaches the desired threshold then you could wire it directly to the relay on that board; it's setup to handle it.

[JonnyMac]

Jeff,

Did you try that circuit board from simplecircuits.com?  I think it's going to be the best for connecting directly to an MP3 player as it has a transformer on it that matches impedance and provides isolation.  Keep in mind that it's not a color organ (which separates the audio by frequency) its a threshold device.  You would tune it so that the relay is off until you get a lighting crash on the audio track

Since you're good with audio you might consider laying out your lighting track on one channel (left) and then laying control tones on the right.  This would give you control over when the light flashes in relation to the lighting.  It also allows you to set the control output level and timing so you don't have to worry much about the threshold setting on the device. 

This is the *problem* with using your actual lighting channel with a threshold detector: it doesn't accurately simulate nature.  Lighting that is right on top of us has the light and sound very close together -- but still, the light always flashes first.