thoughtprocess01

Ok, I realized that last post was way too long. Sorry. I made a flowchart to describe my questions more succinctly. Two questions: 1.) Are resistors going to work to protect my sound card's outputs but still allow enough signal through to the ADC? 2.) What's the best way to interface the 5 volt DC output from the stamp to the 120VAC lights? Thanks again, Jon

I'm considering undertaking a project to control lights for my band using analog audio signals corresponding to individual drum hits. I have a pro audio sound card with over twenty ins and outs, so having a line-level out for each drum is no problem. I included a screenshot of the software I record with in order to give a feel for what I'm doing. The point just pass the cursor shows a roll down the toms that would be awesome to sync to colored lights. I have a few issues to figure out, though. I know I'll be using a basic stamp to sample the analog audio and convert it to digital. I'll set a threshold above which the light should be triggered for each channel. What I'm wondering about is interfacing the input and output. First of all, I expect to be using quarter inch audio cable to get the audio out of the sound card and into the microcontroller, so I'm wondering if I'll have impedance matching issues if I try to go directly into the microcontroller with such a signal. Secondly, I'm wondering about the best way to interface the logic outputs of the microcontroller to the 120 VAC lights. I've used MOC3011 optoisolators before, but found that they have a tendancy to get hot after a few minutes of switching at even modest frequencies. This wouldn't be a problem, but apparently heat is enough to turn on the phototransistor inside and they freeze "on" until they cool. Another option is relays, but they're expensive. Also, the problem with both of these options is that they provide only on/off capability and I would have a hard time implementing PWM fading (for instance to match the transients of a crash cymbal hit). Perhaps a relay is fast enough to do this, but I'm thinking there's a better solution. Any help any of you could provide on these issues would be greatly appreciated. The other attachment is a scan of my current thoughts about implementation and any comments regarding that would be great as well. Thanks, Jon