color organ help...

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dacflyer
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color organ help...

Post by dacflyer »

ya i know, a blast from the past.. but with a different twist.

from what i have seen a lot if not most of the color organs, their frequency responses seem to overlap each other.
i am looking for something like a narrow band type..where the low, medium and high bands have better separation.

i have looked around on the net and cannot really seem to find what i am looking for.
would love to have a 4 ch organ..but could settle for a 3ch.

anyone have experience with such ?
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Externet
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Re: color organ help...

Post by Externet »

Hi.
Feed audio to four bandpass filters; probably a quad op-amp will suffice to separate the channels. (Or 1 low-pass, 2 band pass and 1 high pass) to clearly differentiate bands apart. (~150Hz, 800Hz, 2000Hz, 4000Hz)
I remember once using a sawed-off board portion of a seventies stereo to salvage the 5 band equalizer to do it.

What lights do you plan to use? Incandescent or LEDs ? For LEDs, perhaps you can get away with four LM380. Connect their audio outputs to four of these:
----> http://s588.photobucket.com/user/Innern ... ort=6&o=72
It's a 1-channel column of ten LEDs, been working for >10 years, no hiccups, sealed in a test tube.

----> http://www.bowdenshobbycircuits.info/2Ofilter.gif
Bandpass can also be built on single op-amps ----> http://www.bowdenshobbycircuits.info/opamp.htm

For true portability, I still have a couple of these from the candy store, unused unwrapped:
----> http://www.dx.com/p/sound-and-music-act ... CSNjs8Yo0g
but they are NOT that sharp with bands separation.
Also, ----> http://www.dx.com/p/replacement-sound-a ... CSOOc8Yo0g

:grin: ----> http://www.youtube.com/watch?v=lPlNaybX2vg
:grin: ----> http://www.youtube.com/watch?v=UJ1AOl6m ... FEF6F676FF

Now, if you reeeeeally what a home run, use a cube on each channel:
----> http://www.jameco.com/jameco/workshop/j ... -cube.html

Not cheap ----> http://www.amazon.com/HypnoCube-4Cube-4 ... B005BYFLHC
and ----> http://www.seeedstudio.com/depot/Rainbo ... p-998.html

-Sorry for the overdose !
- Abolish the deciBel ! -
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dacflyer
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Re: color organ help...

Post by dacflyer »

i guess i need to study what filters and band passes are..
i kind of built me one using op amps, but i do not get enough band separation.
need to experiment more with it i guess..

i plan to use Led's R,G,B,Y. 4 color
i even tried playing around with a old salvaged 5 band EQ i scrapped out of a old stereo..
maybe i am just not working with it right..maybe i need to add something to each band output to make it work right..

i already built one CUBE, not planning to build any others for a while.. already went cross eyed building one of them. and then the code i found online was not all that great. seen some that used other processors and was able to take on better code..

but in the end i'd like to build a color organ that had adjustments for each band of some sort or another.
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Re: color organ help...

Post by sghioto »

Digital is the way to go. Using a PICAXE 08M2 microprocessor and the "pulsin" command allows exact frequency separation with no overlap.
The "pulsin" command allows you to measure the length of a frequency which is then stored as a number in the variable w0.
Here's a variation of a circuit I use at Christmas time modified using four LEDs and a simple code.


red: pulsin C.3, 1,w0
if w0 > 68 then
high C.0
endif

green: pulsin C.3, 1,w0
if w0 > 51 and w0 < 69 then
high C.1
endif

blue: pulsin C.3, 1,w0
if w0 > 34 and w0 < 52 then
high C.2
endif

yellow: pulsin C.3, 1,w0
if w0 > 24 and w0 < 35 then
high C.4
endif

delay: pause 100
let pinsC = %00000000
goto red


The higher the value of w0 the lower the frequency will be. The value of w0 will also determine the amount of time in ms the LEDs will stay on.
You can experiment with different ranges of w0 to cover wider or narrower frequency bands.
Audio input needs at least 1 volt rms for good response but do not exceed 5 volts or input might be destroyed.

Steve G
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Picaxe 08M2 color organ.jpg
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dacflyer
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Re: color organ help...

Post by dacflyer »

sghioto>> thanks, i think i will look into that,, it looks very simple also.
i am not good with writing code at all. but i can burn it on a chip with no problem.
would my pick-it programmer work to burn this chip ?
if it works, i'll play with it and see how it does..

can you explain the W0 a bit more..examples of frequency ranges.

example... what exactly am i to understand here..

green: pulsin C.3, 1,w0 <--- why does it say Green here ? and what is "C.3?"
if w0 > 51 and w0 < 69 then <---- this i do not understand.
high C.1
goto blue <--i am guessing this is the blue led ?
endif

and then there is ----> let pinsC = %00000000 <---- whats this for ?

i am really wanting to learn code,, but just reading books etc. does not work so well for me..i am more of a hands on type, but there is not any evening classes around here..and i work during the day..sigh...
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Re: color organ help...

Post by sghioto »

If I have to explain the code then you are pretty "green" at this but don't despair help is on the way :wink:
I'll go line by line:

green: pulsin C.3, 1,w0............................' green is just a label I gave to this segment of code, C.3 is the audio input pin. see the schematic. the 1 after C.3 means measure the pulse from a low to high transition
if w0 > 51 and w0 < 69 then............' represents a range of frequencies, if the value of w0 from the above command is between 52 and 68 then the next line is executed and
high C.1.......................................' the green LED turns on

goto blue....................................' this means jump to the next segment of code named "blue" but I actually don't need this line because
endif............................................' this line will do the same thing since "blue is the next segment of code anyway.

If the value of w0 is not between 53 and 68 the code will jump to the next line after the "endif" command which is the label "blue".
I'm going to edit the code in my previous post to reflect these changes.

let pinsC = %000000000...................' just a fancy way of turning all the output pins or LEDs off.

Again the pulsin command will measure the length of a pulse or frequency and give it a number which will then be stored in the variable called w0. W0 is just one of 14 word "variables" available in the chip you can use. I picked w0 because it's the first one on the list so to speak. I could have stored it in any word variable from w0 thru w13 if I wanted to.

I had to experiment with a tone generator to get some values I assigned to w0. This code is just a starter program but I did breadboard it and it seems to work OK.

This code only works using the PICAXE family of microprocessors, I don't think your PICKit will work in this case. Programming is done using a simple cable if you still have a serial port on your computer or a special USB cable is available for around $20 or so. Go to http://www.picaxe.com/ It so easy getting started and learning you'll kick yourself in the butt for not doing this sooner. :smile:

Steve G
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dacflyer
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Re: color organ help...

Post by dacflyer »

ya, i am about as green as you can get.. i have a hard time understanding the language
and how to assemble it ( grammar so to speak )
i do have a old computer is still save for such serial use..still has win98se on it..lol
cannot do much on the net with it any more.. but i still use some programs i have on it.

i am trying to learn.. but not easy to do alone..
but i will order me a few of the chips and see what i can do..

is there a method to determine frequency and range i want for a channel ?
sghioto
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Re: color organ help...

Post by sghioto »

"is there a method to determine frequency and range i want for a channel ?"
Yes there is. I'll get back to you tomorrow on how I did just that. the Software Editor will only work on XP and above so you will need to purchase the AXE027 USB cable to get started. Order the cable and chips from USA distributor PHAnderson, they have lower shipping cost.

Steve G
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Re: color organ help...

Post by dacflyer »

i do have a USB to serial converter already ;)
was just mentioning that i do still have a real serial port still :D
sghioto
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Re: color organ help...

Post by sghioto »

Great! You just saved yourself $20.
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Re: color organ help...

Post by dacflyer »

WOooHooo...lol
sghioto
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Re: color organ help...

Post by sghioto »

"is there a method to determine frequency and range i want for a channel ?"

After you get set up and breadboard the circuit the programming cable also allows data from the chip to be sent back to the computer for display on a window called "debug" when using the software. In order to use this feature you only need to add the line "debug" anywhere in the program. This bit of code is all you need for determining the w0 value for any frequency

main: pulsin C.3, 1,w0 ...........read frequency on input C.3 and store value in w0
debug ...........display value of w0 in debug window
goto main ...........go back to label "main" and repeat

I used this on-line tone generator from http://onlinetonegenerator.com/ for my signal source connected directly to the audio input. All you have to do is type in a frequency, click Play and the debug window will show you the value of w0 :cool: Example, 440hz or note A (fourth octave) gives a value of 112.

Cheers
Steve G
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dacflyer
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Re: color organ help...

Post by dacflyer »

can it do a frequency range per channel or will it only lock in on a exact frequency ?
sghioto
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Re: color organ help...

Post by sghioto »

Any frequency range you want.
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Re: color organ help...

Post by dacflyer »

i been shopping around for the chip, but with S/H its coming to almost 6-8$ for 1
any sources you know of for cheaper ?
i'll check ebay..did not think of them yet ..duh..lol
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