Post by thread:[EE] Beat Flasher

I am thinking about building a PIC based flasher that flashes to the beat of the music. I am sure that it has been done before, I just can not seem to find it via Google or on the PIC_List archives. One way is to have a low pass Op-Amp filter that connects to the PIC A/D input or Comparator input and either turns the LED on or off when ever a signal edge is detected. I keep thinking that there has to be an easier way. How do the cheep designs do this? A passive low pass filter seems like it would load the driving circuit, so I am assuming that it requires an Op-Amp. Any pointers would be greatly appreciated. Phil

> I am thinking about building a PIC based flasher that flashes to > the beat of the music. I am sure that it has been done before, I > just can not seem to find it via Google or on the PIC_List archives. Google for color organ circuit eg top result http://www3.telus.net/chemelec/Projects/Color-Organ/Color-Organ.htm or sound-to-light circuit http://www.faszl.com/soundlight.htm

I have always wanted to stick a little mirror to a speaker cone and fire a laser at it while it is pumping out tunes. It would have to look impressive I think. One day .... Justin On 8/2/05, Phil Keller <spam_OUTPhilTakeThisOuTpkeller.net> wrote: {Quote hidden}> I am thinking about building a PIC based flasher that flashes to the > beat of the music. I am sure that it has been done before, I just can > not seem to find it via Google or on the PIC_List archives. > > One way is to have a low pass Op-Amp filter that connects to the PIC A/D > input or Comparator input and either turns the LED on or off when ever a > signal edge is detected. I keep thinking that there has to be an easier > way. How do the cheep designs do this? A passive low pass filter seems > like it would load the driving circuit, so I am assuming that it > requires an Op-Amp. > > Any pointers would be greatly appreciated. > > Phil > > > > -

While you can do this with an ordinary pic, I think this would be a great first experiment with a dsPIC. Good luck. Mario {Quote hidden}> I am thinking about building a PIC based flasher that flashes to the > beat of the music. I am sure that it has been done before, I just can > not seem to find it via Google or on the PIC_List archives. > > One way is to have a low pass Op-Amp filter that connects to the PIC A/D > input or Comparator input and either turns the LED on or off when ever a > signal edge is detected. I keep thinking that there has to be an easier > way. How do the cheep designs do this? A passive low pass filter seems > like it would load the driving circuit, so I am assuming that it > requires an Op-Amp. > > Any pointers would be greatly appreciated. > > Phil > > > > -

Justin Richards wrote: >I have always wanted to stick a little mirror to a speaker cone and >fire a laser at it while it is pumping out tunes. It would have to >look impressive I think. > > > It does look interesting. Just take a cheap laser pointer and attach something reflective to a speaker and try it out. Doesn't do much good for the music quality though. -- Martin Klingensmith http://wwia.org/ http://nnytech.net/

On Tue, 2 Aug 2005, Justin Richards wrote: > I have always wanted to stick a little mirror to a speaker cone and > fire a laser at it while it is pumping out tunes. It would have to > look impressive I think. I did that a long time ago. There are problems. You have to use proper optics to project the tiny movements and the laser starts looking dim real quick by the time the image is larger than 2". Peter