32 RGB LEDs - 8 Footer - Playing with the music

Forum 2005-2010 (read only) General Exhibition
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This is a two 16 RBG LED strips, four foot each that can respond to the music and run patterns.

Here is a link to it listening to some piano music it likes.

It moves to all kinds of music from techno, bass, alternative, old stuff like cab calloway and as you see, piano music :).

Here is a link to it running some patterns:

Details:

Created in four foot sections. Then put side to side and glass added in the front for effect.

The build consists of starting with 2 inch pvc pipe, sliced in half (butter fly'd) and holes drilled every three inches.

Then the RGB LED was put in from the back and a slice of acrylic tube placed around it .. then then filled with hot glue. The encased RGB Leds are then wired together in the back for 2 way multiplexing (two R,G and Bs (ANODES) are linked together .. but not the grounds). The wires come out as four flat eight conduit wires for each 16 light - 4 foot section. 24 hot wires (8r, 8g, 8b) and then 8 grounds, two from each set of two.

Then a set of three shift registers is connected to the 24 anode wires to the leds and the remaining 8 wires are split up in sets of four and to the two mutliplexed grounds. So it took 6 total shift registers to run the 32 lights.

Running it:
I implemented software based PWM using SPI shift register updates on a regular interval and got results that look good. I can send a hue from my computer and the LEDs match it.

This uses the RGBCommonLED library I posted a while back (as does the other post of RGB House Lights). Also I can update the modes etc from my computer using the SerialCommander I posted a while back as well. The system can read music, PWM control 32 RGBs, do music and read serial commands and handle patterns. Alot for that little puppy, I am amazed it can handle all that.

For Music:
I popped open an old computer speaker system and read the values going to the speaker via an analog pin. Using an actual IC for this would be the best route .. but just wanted to see it move with the music and have no idea where to start with one of those fancy chips (but have one on order).

Thanks:
Thanks to all the great help provided here on the forum to get to the point where I can make this happen. Still learning but wanted to share some success.

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hey marklar,

Really good loking! The housing is beautiful.
I want to build a 64RGB-Led wall poster myself as my next project Could you provide some more Informations about how to wire up the LEDs and how you build your housing? A real Documentation (used parts, code) would be great. Looking forward to see more from your project!
Greetings, Jan

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This was a prototype to see how feasible it is to use 595's to run an array of RGBs. While it was functional, I wouldn't wish the development / build process on anyone. I am also a newbie, so me building a design for others to follow would most likely steer someone in a bad direction.

I tried the TLC5940 chips but am having color balance issues, which is really rough .. cause the chip seems great and works great for the most part.

Next I ordered some of the daisy-chain capable LEDs from Bliptronics .. from this post:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1275457576

If you are really interested in learning about doing this with 595 and/or TLCs .. there are some good posts and I can help if you like. I'd love to figure out dot correction, etc.

However, if your desire is to see colors moving on command .. you may want to take the easy route and test out a sample of the LEDs from that post. I did and have to say I am very pleased.

Let me know if you want specifics about the above setup or the mentioned chips or leds.

Shift register selection:
I have 595, TLC5940 chips working. 595's can push common cathodes just fine. Have not tried common anode with 595s.

Got the TLC working with common anode (no multiplexing) and with common cathods (required multiplexing 3x) (see 112 rgb table).

Daisy chain "out of box" leds:
have the 8mm, 20mm and 50mm versions from blip all working (all daisy chained together .. not sure if that is a suggested use however).

Of the three I like the blip LEDs the best and the 595's second only due to my own issues with the TLC. I prefer the TLC over the 595s logically but prefer a soldered solution overall.

Best of luck with your project.

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Hi Marklar,

I'm really curious how your code works for responding to sound. I currently have a working multiplexed array using TLC5940 & 595 Shift registers. I would just like to add some sound reactive effects to it and not quite sure how to approach it, any tips/code?

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This was my first attempt at reading music and I did it using the direct output to the speaker. The method was not great but now I actually have a nice chip that pulls 7 bands of detail using 2 digital and 1 analog pin.

This chip...
http://www.bliptronics.com/item.aspx?ItemID=111

Plus this adapter ..
http://www.proto-advantage.com/store/product_info.php?products_id=2200001

Plus these .33pf capacitors (along with other radio shack partsA).
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320517060962&ssPageName=STRK:MEWNX:IT

I was able to put together a pretty nice board using this .. on breadboard first and then an easy solder job (the SMD chip to the adapter being the most challenging but is still SMD 101).

If you already have components to read the music, let me know what you are using and what you have for start code (something that can make one light dim/brighten with amplitude) and I can provide some assistance on how to get that and turn it into something cooler :slight_smile:

Hope that helps get you started.