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Topic: DIY Christmas lights elG-35 (Read 2 times) previous topic - next topic

marklar

Nice video and build with raw leds. I saw some fading in there - what types of chips did you use - TLCs?

KirAsh4

WS2801s, one per LED, daisy chained.

My next project will be using its larger brother, the WS2803 - 18 channels versus 3 on the 2801.

marklar

Ah, so you are using raw LEDs and the ws2801 chip and doing the soldering yourself as opposed to getting the chips built in. 

The WS2803 with 18 channels looks great - checked out the specs - looks like the control protocol is the same - killer!  The WS2803 looks like a nice cost saving way to implement strips and matrix form factors.   Even on ebay they can be had as little as 1.39 each at the 100 level .. and that runs 6 RGBs each. 

That may be the most cost effective solution yet - thanks for the info.



KirAsh4

Yep.  I designed the PCB myself (11mm x 14mm), chip, resistors and cap on one side, and the RGB LED on the other side.  Reflow solder the chip and other components, and hand soldered the LED.  The PCBs were paneled into 4x3 larger pieces which made it a lot easier to hold in a vice as I soldered the LEDs, then I used a Dremel cutting tool to cut them apart.  Solder the 4-contact ribbons on, controller at the end and you get what you saw in the video.  I get the WS280* direct from manufacturer so they're much cheaper, even with shipping.  But then, I also get then 1,000 to 2,500 at a time, if not more - if you're interested, I'll send you a few after my next shipment in January.  I'm getting the 2803s in DIP version for now because I want to do some breadboard testing for something else down the road.

Attached is an image of the PCBs in the various stages, and what one of them looks like up close (just the IC side) ...  This was meant to be for a parade, so I made several strings (10 LEDs each), connected two strings to a controller (my design) which also has an RF module on it.  During the show, all the strings display the same sequence of lights, so you get a large group of people together and they all are blinking the same patterns, or be completely random.  After the parade, I took the whole pieces, as is, and hung them in the window.  So there are 8 controllers in the window, 16 strings total.  The first controller acts as the master and tells the rest what sequence they ought to be playing.

Sure I could've redone it and built one single controller to drive all the strings in the window.  But why re-invent the wheel when it's already there (albeit in single form.) :)

marklar

That is some seriously nice work.  I am very interested in seeing what you come up with for the 2803s.

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