Blinking bi-color LED on music?

hi people,

I'm looking for a simple circuit wich can blink multiple bi-color 2-pin LEDs(using both colors of course).
It needs to blink on the beat of music, using a mic as input.
I would also like the sensitivity to be adjustable.
And it would be fantastic if all this could run on 3 AA batteries(4.5V).

I've done some research but couldn't find anything like this, only circuits that blink a bi-color LED or flash a LED on music.
Unfortunately I haven't got enough skill to combine these into a working circuit.


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I can help. How do want the led to blink?

Like one color at one volume, but both colors with a louder volume(beat)?
Oh...two pin LED. That complicates things a little. Anyway, answer my above question and I'll see what I can do.
theexternaldisk (author)  Awesome-aniac5 years ago
it's fine if the blink is triggered by lets say the beat and that every beat it flashes another color

and thanks for the fast reply
That will be too difficult. Also, instead of bi-color, get an RGB LED with 4 pins. To make it flash as you have said, I think you will need a microcontroller or something. Maybe someone else has a suggestion for an easier way to do this?
theexternaldisk (author)  Awesome-aniac5 years ago
what if the LED is like color 1 and every beat is flashes color 2?
You would have to invert the voltage every time because that is how a bi-color led works; one color, one polarity, and reverse the polarity, you get a different color. An RGB LED is still your best option.
theexternaldisk (author)  Awesome-aniac5 years ago
But i've got the bi-color LEDs and i want to use them. can't this schematic be altered so the NE555 has "sound" as a trigger instead of the R C?

Or perhaps use this schematic and use "sound" on the inputs making sure that both inputs aren't triggered at once
The way a bi-color 2-pin LED works is that when you connect the positive supply to "pin1" and the negative supply to "pin2", one color lights up. Reverse the power connections to get the other LED to light. So, you would need to alternately invert the power connections to the LED to get both to light alternately.

You need a color organ (microphone operated), the output of which goes to a counter or flipflop which feeds an inverter system to which the LED is connected. You would also need a way to make the LED turn off in the absence of a beat.

Taking all that into account, I think you would be better off with a microcontroller solution (this, coming from an analog guy!). If you search for "microcontroller color organ" with plans or schematic after it, you should find something that should work.

Now if you were to use a 3-pin LED, it could be simplified for analog construction. As most 3-pin LED's are common cathode, so you only have to worry about  using the counter/flipflop to select which anode is active, with a transistor switch in-line with the anode. That would be a design to look at if your criteria would change.