RGB light strings

**ydeardorff** · 01-09-2012, 06:04 PM

Does anyone know how I can hack one of those cheap RGB Christmas light strands? The RGB node strands are 1 buck a bulb, being way too expensive.

Some 100 bulb strands on ebay are indoor ones, but could be sealed up using RTV. If the controller wiring could be figure out, perhaps I could cut off the controller, and run them via DMX as a simple RGB strand. Its better than buying and installing 4 strands per item in my yard chewing up 4 channels per item in my controller boards. I could just use a 3 channel DMX controller per item, and only one extension cord rather than 4.

The cheapest thus far I have found have been ridiculous for shipping, although the asking price is right where it should be.
http://www.aliexpress.com/fm-store/7...-a-string.html

If someone knew how to hack the cheaper RGB strands that come with a controllers on them, it could save a lot of money. A little sealant would make them outdoor usable. I was thinking about using them for my planned mini trees out front. But at 300 plus lights per tree, nearly 100 bucks a tree isnt going to work for me.

**kychristmas** · 01-09-2012, 06:32 PM

Check out diyledexpress.com. They have both intelligent node strings and straight rgb strings currently in preorder. And they are already waterproof.

**ydeardorff** · 01-10-2012, 01:30 PM

Those Dumb RGB products are more like it! Thanks!!

**djulien** · 01-11-2012, 10:47 PM

Originally Posted by ydeardorff

Does anyone know how I can hack one of those cheap RGB Christmas light strands?

To answer your original question (for informational purposes), the LEDs shown in the link are basically just a string of LEDs in parallel (with a series resistor between each LED element and one of the power supply lines), so if you wanted to turn individual LEDs on/off in a string like that you would need to "hijack" the common lead of each LED and control it separately. A smaller number of pixels wouldn't be too bad, but if you were doing a string of, say, 50 or more pixels then that would be 50 extra wires to run along side (unless you did more extensive surgery on the string), which would get quite bulky.

A compromise would be to turn it into a marque-style string, like those 140 ct, 4 loop incandescent mini-light strings. In that case, it would only take 3 extra wires running along side the RGB string, and you would wire every 4th LED to the same common lead. (I hope that made sense; if not I can try to make a diagram).

don

**n8huntsman** · 01-11-2012, 11:28 PM

ydeardorff, Welcome to DIYC. I read your post on Light Show Pro regarding LOR. Just curious what exactly you are trying to accomplish? Perhaps I can help point you in the right direction. Do you want to control the color of every single "bulb" individually, or are you ok with just changing the color of the entire string as a whole?

**chilloutdocdoc** · 04-04-2012, 12:21 PM

I'd suggest something like the RGB lights from diyledexpress.com and then a DMX dimmer. I'll post some videos a bit later (when I'm not at work) with my stuff on the workbench, it's the easiest, and fairly cost effective.