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Topic: House Lights 2010 (400 RGBs) - Just in time (Read 5124 times) previous topic - next topic


I had posted my first installation of lights a year ago, which was 44 RGB LEDs connected to 595 shift registers.  I posted the code and details on how it was accomplished.  It was a bit sad when we recently pulled them down (ouch alot of work to build and put up).  

We upgraded to use 400 more advanced LEDs that have a built in WS2801 chip (kinda like the LPD6803 but with 16 million colors).

The system is run by one MEGA that reads music and computer system and a single "zone" which is the 400 lights.  The master mega tells the zone(s) what to do via 2wire.  The computer tells the mega what to do via standard serial.  But the system can run without a PC as per most arduino projects.  Also, with a few less LEDs .. no need for two arduinos.

We have this same installation at a local night club running two zones now and growing - the design is scaling up well.

This required power to be run from both sides of the house and uses 2 - 100 to 150 watt power supplies (5 volt versions).

Here are some patterns that are controlled by the PC application.  I don't have good details / shots of the PC application as it is under development still.

The coding and other efforts required to pull this off made me feel like it is was worth showing the end results of using these types of LEDs. I order in bulk from factories in china for installation only.  I do not sell these to the public but search the forums for "holy grail" and you will find someone that does and provides code.  That was the post that got me going in this direction and I can't thank the OP enough, but won't post the site because I get yelled at for spamming - so you'll have to search it out - sorry.

As for power usage ... the "star fader" pattern only runs about 30 watts on full bright and under 15 watts (average) with a medium brightness setting.  I have not killa-watted the rainbow .. but from past experience it will pull about 60 watts on full bright .. with 120 watts running full white - full bright.

Happy Holidays.


Beautiful, Congratulations on the design, and merry xmas!!!!



Very impressive for sure. Did you have to use the Mega to do it, or could it have been done with a standard Arduino? 120watts.. at 5v.. Man that's some serious current draw. :) I'd love to see more details on how the "WS2801" chip you're using works, and how you built the circuits and such.


The mega was not needed for this, in fact a standard arduino did all the heavy lifting.  That said, trying to read music, computer control and control over 400 leds is a tough job for a single arduino.  Running 300 or less - no problem.  Really there is no circuit to speak of, outside just the arduino with pins connected to the output connector (three pins including connecting grounds).

You can find fastSPI code here.



Dec 26, 2010, 10:48 pm Last Edit: Dec 26, 2010, 10:48 pm by amacmullen14 Reason: 1
Now next year, use  400 EL wires running vertically from the roofline to the ground.


How much does el  wire cost per foot or meter ?


Seems to be roughly a buck a foot, plus inverter, plus control interface.  

I personally have no use for EL wire since it is single color.  Also - it takes a different mechanism to run it being A/C, hence the sparkfun el-sequencer.  


Can you clarify some questions about the WS2801?  I've been trying to find strips and how to control them.  As far as strips I see they come in 5m rolls and pre-wired with 5 wires.  So I was trying to figure out what the 5 wires are.  I found a data sheet but it seems you only need power, ground, data, and clock.  Is the 5th wire the polarity reverse wires?

As for sending it the grey scale data, what is the protocol for that.  Based on the data sheet I couldn't tell how it knows when the first frame is being sent.  Most chips you precede the data with a single high bit.


I got WS2801 based strips and had no luck getting them to work and they had five wires.  The 5th wire on mine is an additional ground.  That said, still not sure if it was a bad strip or just a bad user that maybe blew it up (that would be me).

I have gotten LPD6803 based strips to work - but have not been happy with the end results .. they seem to almost "twinkle".  I have not really worked hard on that problem as I normally use the pixel style, which work well for my purposes.  

On the house, you are looking at 400 "pixel style" (like the ones from bliptronics, but with ws2801 chip instead of the LPD6803).  

I can't for sure tell you that the strip will work or work well until I have success with it myself.  I can attempt to help if you got the strip and are having issues getting it working.

Best of luck!


Thanks for the info.  I might get a roll and check it out.  However, the second part of my question, what is the protocol for sending it data?  Is there is single bit to indicate the first led then 8 bits per color- 24 bits per led after that?


The datasheet says to stop the clock for a short period of time, then send 24 bits per LED.  However you may want to try using this code.



The project I am doing already uses two devices on SPI.  So I am going to have to do something similar to the bliptronics LEDs and use a timer.  I am using the bliptronic LEDs and they are awesome.  But I am always open to trying to find something brighter.

I originally started with a TLC 5947 and some really bright RGB leds..  However, once I saw the blips and the shift register style LEDs I prefer to go that route, a lot less wiring and easy to expand.

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