sound to light modulation

Go To Last Post
5 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hey there people.

Currently I am attempting to get a light(led) to modulate to sound- a feature seen in many commercial dimmers and sound activated lights.

Basically the led can be set any dim level with 8 bit accuracy (PWM dimming). So the smarts of getting the LED to dim is already sorted.

I'm more interested in the best way to get pick up some sort of beat from an input audio source.

I was thinking some simple electret mic with a passive LPF going into the ATMEGA8 ADC could be an idea. Is it?

As for working out when beats are happening. I'm getting confused- obviously i dont' want to delve into doing DSP on the AVR if i don't have to (especially with software pwm being juggled at the same time :).

Can anyone offer any insight?

thanks heaps.

odd

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I do not know alot of anolog elec.
But can you use a band filter to filter out the frequences of your beat and use a level holder (I think that is its name, used one along time ago ) And use the level for the intensety of your led. Our you can use only specify levels for your led intensity.

Maybe a stupid idea but analog elec is not my thing

Pinkpanter

admin's test signature
 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I suspect that the perception of brightness is not linear which could give you some more opportunities for calculations and such, though I am pretty sure people would still recognize a linear relationship with the light and the sound.

admin's test signature
 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I'm more interested in the best way to get pick up some sort of beat from an input audio source.
=======================================
You want the light intensity to be proportional to the music volume? You need to detect the 'envelope' of the music..... diode into a cap into the a/d converter. You want 3 channels for lows, mids, highs? Then you need hi, mid and lo pass filters before the envelope detector. This is a 'color organ'. You can get one from Ramsey Electronics ready to solder together for about $20 as I recall....

admin's test signature
 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Nuts and Volts October issue has pumkin on the cover that has LEDs driven by either sound (analog circuitry), or a "candle flicker" (a PIC MCU).

Scott

admin's test signature