RC filtering for basic sound to light of leds using pic and MP3

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ghostman11

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Hi guys i have been side tracked with a small offshoot project and need some info,
the project is for my little girl and is a offshoot of little ghostmans 1200 led constalation project.
what we want to do for my daughter is make a couple of LED stars using around 40 LEDS and 5 shift registers, this part is not a problem and we have that pretty much sorted, we also want some bedtime music etc for her while the LEDS are 'twinkling away, what we are going to use for this is a butchered MP3 player that basicaly has its switches taken out and the switch signal controlled by a couple of pins on the pic so it can auto play when it get dark etc. this we also have sorted and is working ok.
i know we could have gone with sound chips etc but wanted to keep it simple the MP3 player works well and only cost around £3!
now the bit we havnt sorted is getting the stars to twinkle to the music. dosnt need to be anything fancy, i have done some googling and reading and think what i need to do is use some kind of RC filtering?? possiably 'BAND PASS??' so my question is am i on the right track?
if so how do i implement it? do i take the MP3 output go through the filter first then the speaker or do i parralell the output from the MP3 to the filter to provide sound to light?
if anyone can talk me through the principles of how its done i would be grateful, like i said dosnt have to be all singing all dancing.
many thanks chaps
 
There and easy way to do this I would sample the speaker output, with fast rate on a adc pin to get some numbers that could be used to display on the leds they will mach with the beat of the sound.
 
There and easy way to do this I would sample the speaker output, with fast rate on a adc pin to get some numbers that could be used to display on the leds they will mach with the beat of the sound.

cheers Burt i completely overlooked the obvious would save messing with filters! and keep it nice and simple, i will have a go with that and report back
 
have bread boarded it out and works great! will make a pcb for it tommorow and se about posting some pics. LittleGhostman however is more amibitious than me and is working on a MKII version that uses filters and interupt on change pins etc lol purely for the sake of doing it i will keep you posted of his progress also!
 
LittleGhostman however is more amibitious than me and is working on a MKII version that uses filters and interupt on change pins etc
How about a link to his project?
 
he dosnt have a link to it! but i will certainly see if i can get him to do a post if anyone is interested, keep in mind he is only 11 so dont exspect top flight engineering, he just wants to play with stuff and learn something at the same time. having said all that he has learnt a huge amount of stuff from here and people like 3v0 who spend there time teaching him. leave it with me and i will get him to do a post
 
My suggestion is to use the IC APR9600 which has 8 channel to save your own voice along with playback of 60 secs on each channel.
 
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