I have never used LEDs before, but being the computer geek I am, I was a pproached by a friend who does some DJing (sp?!?!) with a project. He is building a backdrop to place behind the DJ booth, but wanted it to be very customized. So me being sooo thoughtful said, "Well, i bet I could make your logo with LEDs and have it pulse to the beat." Well guess what...he liked it, and i am stumped where to find a guide on how to pull this off...any help would be appriciated!!! Thanks!
Have you ever worked with circuts? Are you handy with a soldering iron? We need to know these things For somebody like me (who's not real handy with circuts and such) I would just take one of those sound activated cold cathodes, rip out the sound board, and use that to power the LED's. Give it a bit though, I'm sure somebody with more of a clue in electronics will reply
that would depend on a few things... how good u are with soldering et al, how complicated the design was and mainly these two things... size and power... ie how big and what sort of power supply u got
the problem with the neon sound activated pulsers, is not only is their beat detection crap, but they have this ugly strobe effect. The first time i saw on a mates machine, i offered to solder up the lose wire for him, the beat detetion was so crap, i though the circuit was broken Its very hard to do propper beat detection, FFT is complicated, and as i mentioned in a post in here titled sawtooth generation, getting a nice linear fade on an LED is also not straight forward. In short, i would look for a beat detection kit, and have a go at trying to make nice log sawtooths, i am sure it must be possible quite simply because most caps have exp decay.
Here's one I made earlier: That's a very simple transistor switch set to light the led if the amp output puts the speaker in danger of death, and takes both power and signal from the speaker terminals. To drive a few dozen leds I'd suggest a separate PSU and an opamp comparator to switch at a set volume level, bass beat is usually loudest, or you could boost and filter the line signal, like one channel front-end of the vu-meter/spectrum analyser circuit posted here recently. Some capacitance on the final transistor switch base lead will give some peak hold & fade if you fancy it. Comparator circuits are very easy to build & the parts dirt cheap, so do not panic.
Ok, lemme answer a few questions you asked me: 1) I am quite handy with soldering, and have worked with circuits before 2) I am working with nothing right now - I will need to buy everything i need Has this been sucessfully done before? Could I take anything that pulses to a beat and rig it up to some LEDs?
basically you could take anything that pusles and put that to a driver circuit to make the LEDs pulse, its just, what effect are you after, most of the pulses give a rather naty strobe i don't like the strobe, its not finished enough for me ! Best way is to have it light up instantly and then fade away, this looks soo much better, full intestity on each beat, same speed decay each time (normally this is fast, about 250ms max time for the fade out). This looks neat, so neat infact i have just been writing some ASM for a winamp version for a mate.
its naty to bring me up on that u know! But still, i like my 512bit resolution LED PWM control (okay only 256 useable setings, but still, its the bitt-age that makes it sound big.)
I know I am not that good with circuits to design a clean strobe. Would you be able to write up a tutorial to help everyone who is in my sitution? Thanks so much for all your help!
