Hello there! I’m new to this forum but very interested in building a MIDIbox SID and I was wondering if there was any way to implement a 3colored LED in some way? Like this one: http://www.kjell.com/content/templates/shop_main_details.aspx?item=90540&path=69800000,71600000,71630000
It would be totally kick ass to have 8 different LEDs that shines according to the soundvolume of each chip. Blue for low volume, yellow for medium and red for max.
… no problem. You just connect them like 3 individual LEDs except that they have a “common”-connection on one end.
Why 3 colours? You can mix them:
red & blue = magenta
green & Blue = cyan
red & green = yellow
… that gives you 6 colours.
It just needs some testing with the resistors… specially red & green, if you don’t want a dirty or even brownish yellow.
Greets, Roger
Yeah, thought of that too. One would be able to have the whole spectrum of colours. The good thing is that they wont be brown or anything like that. Colours work that way when you mix paint, if you mix them all the cocktail becomes black. But when you add different colours of light they subtract and become brighter. So if you add all the colours you will get a white light.
I guess ill have to experiment alot. But they are pretty expensive 5€ a piece from kjell.com. I bet they can be found cheaper elsewhere.
i got mine here:
http://www.ledtuning.nl/catalog/index.php?cPath=46&osCsid=d7b49db6c4b020ab95fe23bc314e8ab8
One would be able to have the whole spectrum of colours.
Using the full spectrum only makes sense to display e.g. intensity of a parameter. If you want to display the state of function, 6 colours are enough by far. - More colours are nothing more than confusing.
Greats,Roger
I got mine here:
Yeah, thanks for all the replies. I haven’t found any midibox that has multicolored leds, is there anyone here that has actually done it?
If you’re considering making an 8-SID MIDIbox, I don’t think this of all things should be stopping you.
If you want to indicate the volume with a multicolor LED, just use an LM3915 IC (try searching google for “LM3915 VU meter”) on the output of each SID. It costs about $2.50, so 8 of them would be about 20 bucks. Add it to the cost of a hand full of RGB LEDs and a few support parts, and you could do exactly what you are suggesting.
Using the full spectrum only makes sense to display e.g. intensity of a parameter. If you want to display the state of function, 6 colours are enough by far. - More colours are nothing more than confusing.
Greats,Roger
The other problem is the DOUT is binary, so you could only turn each RGB LED on or off, making 7 colours (including white) to have it show the full range you would need to connect it to an AOUT
to have it show the full range you would need to connect it to an AOUT
…which is a horrible idea 
Quote from: Screaming_Rabbit on 2008-02-02 at 18:59
Quote from: Helix on 2008-02-02 at 12:58
One would be able to have the whole spectrum of colours.
Using the full spectrum only makes sense to display e.g. intensity of a parameter. If you want to display the state of function, 6 colours are enough by far. - More colours are nothing more than confusing.
Greats,Roger
The other problem is the DOUT is binary, so you could only turn each RGB LED on or off, making 7 colours (including white) to have it show the full range you would need to connect it to an AOUT
levon if you want to dim a led you can just strobe the DIN.
Right… thats a much better idea… keep in mind that i replied at 5:30 in the morning… 
levon if you want to dim a led you can just strobe the DIN.
… it was early in the morning for CIMO too
I would put a PWM on the DOUT
Greets, Roger
you could do something just like what you mention using a combination of a LM3915 dot/bar driver and a 8 to 3 encoder chip.
the LM3915 takes one of 10 outputs low in response to signal level, so you’ll need to invert them to drive the encoder.
these could then be fed into an 8-to-3 encoder chip, with the output used to drive the LED directly.
ie Q(0) to Red, Q(1) to Green, Q(2) to Blue on your LED.
you could then choose which order your colours should go.
say your LED glows blue at low levels, through green/yellow at middle levels, etc:
[tt]
out 10 (max) - input (7) = 111 = All cells on = White
out 9 - input (1) = 001 = Red cell alone
out 8 - input (3) = 011 = Red+Green = Yellow
out 7 - input (2) = 010 = Green cell alone
out 6 - input (6) = 110 = Green+Blue = Cyan
out 5 - input (4) = 100 = Blue cell alone
out 4 - input (5) = 101 = Red+Blue = Magenta
out 1-3 OR’d - input (0) = 000 = All cells off
[/tt]
Edit: I’ve just realised that this all assumes a common cathode LED, and yours is common anode. No big issue, just patch as follows:
[tt]
out 10 (max) - input (0) = 000 = All cells on = White
out 9 - input (6) = 110 = Red cell alone
out 8 - input (4) = 100 = Red+Green = Yellow
out 7 - input (5) = 101 = Green cell alone
out 6 - input (1) = 001 = Green+Blue = Cyan
out 5 - input (3) = 011 = Blue cell alone
out 4 - input (2) = 010 = Red+Blue = Magenta
out 1-3 OR’d - input (7) = 111 = All cells off
[/tt]
Quote from: cimo on Today at 01:43
levon if you want to dim a led you can just strobe the DIN.
… it was early in the morning for CIMO too Wink
I would put a PWM on the DOUT
Greets, Roger
ehe Roger, it was late night.. when i went to bed, just before falling asleep i figured out that i wrote DIN instead of DOUT but i was already too sleepy to go downstair and correct it, so i said to myself “let s try to guess who s gonna correct my post first” i thought about S1 and eventually Seppoman so it was not a good guess.
simone
so i said to myself “let s try to guess who s gonna correct my post first” i thought about S1…
Hahaha I’ve only just now read this thread 
BTW, Sorry for the flood of replies… I’m catching up on lost time… only 16 pages to go… can’t you guys type slower?! ;D