Light Bar Controller


Checkout this compact LED light bar controller created by Adam Greig!

Sound is picked up by an electret mic, amplified with an opamp, and then ADC'd to an ATtiny microcontroller. The ATtiny in turn pulses a MOSFET to control the sink current to a LED array. A simple design implemented well.

Adam has posted the Eagle files as well as some stellar photos and a video of the box in action. If you've ever wondered how to do audio and LED control with a microcontroller, this is a great example project. Adam's got a great electronics related site as well so be sure to poke around.
Do we also mention we're completely enthralled he re-used his SparkFun box for a greater good? Nice job Adam!

Comments 10 comments

  • Damn, I have been ripped off, I never got any special Sparkfun printed boxed :(
    Nice project, although the video is nowhere to be seen…

    • Oh, you thought the ‘video’ link would actually take you to a video? Sorry. My bad. Fixed now.

  • Can never have enough MOSFETs! Very interesting, and simple design. Oh, speaking of which, how do you get a special Sparkfun red box???

  • Nice barrage of SF components!
    Is there a reason for 3 MOFSETs?

  • Video link seems to go to the project files, but the YouTube link is here: http://www.youtube.com/watch?v=6ihIaNN9UBY
    It’s in the blog post, too.

  • Hey do you have a DigiKey BOM (order) list?
    Or any kind of BOM…?
    Also what are the voltages your driving the LED’s with…?

  • I was actually surprised when I got my sparkfun box, I ordered an LCD couple months ago and didn’t get one.
    But I just received my Arduino + USB cable couple days ago, and got a box.
    I Shall now go on to mount my LCD into my Arduino box.(It just kinda floated around my desk before.)
    Any chance I could get 10% off my next order for mounting a Sparkfun product in a Sparkfun branded box :)

  • I’ve got several of those little red boxes. Just order a couple of small components. The last one I got held two LiPo cells and a tiny charger.

  • Theres only one mosfet, the other two are voltage regulators (5V mcu, 3.3V LEDs).


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