Circuit reguired

[QUAZAR]

Dont know if anyone can help??

I am looking for either a kit, or a circuit diagram to make a light chaser/sequencer.

I have found various kits on the net, but none of the have the requirements I am looking for. I need all the following attributes.

1, 4-8 channels
2, low voltage output 5v (ish)
3, audio input (microphone not line) to drive the steps
4, adjustable sensitivity

I am planning on using this to drive the ttl inputs to a bunch of 100mw red diodes to create a simple beam table effect.

Thanks.

[dar303]

I don't know if there are any laser specific products like this but I know that this exists in th analog synthesizer field!

You could do that with a few envelope followers/trigger extractors and a some filters. Adda a step sequencer to that and you have programmable patterns!
These things come in various levels of complexity, for some simple stuff check out musicfromouterspace.com, there are kits and/or PCB's available.

[djscsi]

Microcontrollers are good for this- The arduino development platform, for instance, makes this stuff pretty easy. www.arduino.cc

The pot would be inline with the microphone and go to one of the analog inputs on the MCU. Code would read the analog input value and trigger the output pins high/low (depending on what the driver is expecting).. A small signal transistor on each pin should be sufficient to power on some small lasers based on the state of the MCU output pins. You can test a simple circuit using LEDs on the output pins, then replace them with transistors/lasers/whatever after you get the software working.

This example tutorial/arduino code would be basically what you would use if you decide to go the arduino route. The code would be modified slightly to use multiple outputs instead of a single output at varying frequency. Some experiementing and debugging would be necessary to determine the input level from your microphone, but it should be pretty straightforward.

http://arduino.cc/en/Tutorial/AnalogInput


Hope this helps!

[mixedgas]

you might want to do something more sophisticated like DMX, but this is start.

http://www.quasarelectronics.com/vel...mputer-kit.htm
lowpass for the clock input (beat)

http://instruct1.cit.cornell.edu/cou...an/lowpass.jpg

prolly the best beat sensor I've ever seen

http://sound.westhost.com/project62b.htm
Steve

[djscsi]

Looks like the first circuit is for switching AC lighting such as spotlights. The op-amp circuits are good for getting a clean sound level into your circuit but they don't help with the question of how to trigger lasers based on the sound. There is probably some IC to do something like this. You could probably do it in hardware with a bunch of transistors with varying resistance to make them activate at different voltage levels (something like that) - but that would be messy and hopefully unnecessary since MCUs are only a few bucks and will do this sort of thing much more easily in software. The Arduino platform makes this even easier because of the large existing base of sample code and schematics, community forums, user support, etc. Just my opinion though!

Edit: I re-read the OP and you just want TTL inputs to your laser drivers, so the MCU should work well without any additional hardware. We are looking into doing something similar using LEDs instead of lasers - An RGB LED "VU Meter" type thing - but this is basically the same thing. There is some good info out there about this if you look for it.

[mixedgas]

Did you EVEN LOOK at the low pass filter, agc, and BASS beat extractor circuit and read the description??

The signal in music varies 30 Db or more.
You need to clean that up to a constant level. Hench the discrete AGC.

Then you need to shed the highs and mids, So he has a the low pass and band pass in the next block.


Next you need to extract the beat envelope, and provide ONE clean interrupt or do you have a magic DSP block and big memory in that ardunio?

The 555 does the interrupt clean up by acting as a one shot and locking out the plus edge of the waveform.

He can then run that signal into the clock input on the velleman kit or the ardunio if he wants to cut his own code.

If he wants to get going quick, the velleman kit has the CLOCK input for the beat extractor
mixedgas

[djscsi]

Hi, no need to get snappy, I was just trying to help. My suggestion was to use one of those circuits to filter the audio input to the microcontroller, not suggesting that it can do signal processing itself. And I missed all the information in the third link, so I apologize. I am not an expert so I guess I will keep my information to myself!

[heroic]

Next you need to extract the beat envelope, and provide ONE clean interrupt or do you have a magic DSP block and big memory in that ardunio?

This is somewhat besides the point, but you can do a realtime 128-point FFT in an Arduino. Those little 16MHz RISC things are fast.

[QUAZAR]

Thank you gents. I think I will go with the Velleman option initially. Dont know why I missed that? Possibly because the site I saw it on didnt mention the output voltage.

I will build as standard initially and add the audio input at a later date. Unless anyone knows of a similar item with a built in microphone?