LED flashing to music - Page 1
Forum section: electronics / beginners

author: awyeh1234
author_rank: Contributor
timestamp: November 05, 2014, 01:18:58 am
content: Hello I am a beginner in electronics and im making this stereo and i want leds to blink to the bass. i was thinking like a circuit that takes the power from the speakers and amplifies it. Can some one help me with it.- Chris

author: Paul Moir
author_rank: Frequent Contributor
timestamp: November 05, 2014, 01:35:30 am
content: You just need to know what it's called.Google "LED colour organ"The lowest frequency will be the bass. If you don't want to bother with the other frequencies, you can omit them.

author: Simon
author_rank: Unknown
timestamp: November 05, 2014, 06:51:04 am
content: Not that I've ever made something like this before but my approach would be to low pass filter your speaker output so that you have just the frequency you want, then you can use either an opamp to drive the LED with perhaps some DC bias if you want to linearize the response or you can use a comparator so that the LED flashes to the beat of the music.

author: hugo
author_rank: Regular Contributor
timestamp: November 08, 2014, 02:01:11 am
content: A nice ic I came across is MSGEQ7 (Graphic Equalizer Display Filter) available from sparkfun.com.It divides the audio spectrum into seven bands: 63Hz, 160Hz, 400Hz, 1kHz, 2.5kHz, 6.25kHz and 16kHz.To control leds and to talk to the ic you also need a microcontroller... use 63Hz band for the bass ...

author: AlessandroAU
author_rank: Regular Contributor
timestamp: November 10, 2014, 09:32:55 am
content: I've done something similar:Sorry for the terrible video, I just took it a few moments ago.This current incarnation uses a computer to compute an FFT but it can be done standalone on an MCU if you like.The easiest way to do this would be to buy one of these:http://www.ebay.com.au/itm/Explorer-RGBW-LED-Lighting-Driver-board-Audio-Synchronization-/331308856935?pt=UK_ConElec_LightingLEDsStrobes_RL&hash=item4d238bf667This board will accept an audio input, take an FFT and set the magnitude of the brightness proportional to energy in each frequency band. However I'm using an arduino over bluetooth/rs232 as my computation is done on the PC instead.The led's I used in the video is this board:http://www.ebay.com.au/itm/RGBY-Quadcolor-4-1Watt-LED-Built-in-Driver-Board-LED-/380456541281

author: Arlen moulton
author_rank: Regular Contributor
timestamp: November 10, 2014, 06:54:19 pm
content: Probably the easiest way to do this would be to connect the negative of a battery to the negative of the led and audio input then connect the batterys positive to the collector of a PNP transistor then the positive audio input to the base and the LEDs positive to the emmitter. Here to help should you need it.

author: darko31
author_rank: Regular Contributor
timestamp: November 11, 2014, 12:00:47 am
content: You can also use IC like LM3915, which is basically bunch of comparators set at different levels. Pair it up with low pass filter at the input and you got yourself a bass VU meter.

author: SL4P
author_rank: Super Contributor
timestamp: November 11, 2014, 01:24:13 am
content: Quote from: Arlen moulton on November 10, 2014, 06:54:19 pmAppreciate the effort - but 1.5Meg of poor quality photos !?Compress or enhance the image quality to bereallyhelpful.Cheers