Driving NeoPixels over long runs of CAT5

[mykrotek]

While working on an outdoor Christmas project using NeoPixel strips, I ran into a small problem. I wanted to be able to have several groups of pixels many feet apart from each other, but still all synchronized and controlled by the same single controller. I worked out a way to use RS-485 drivers to push the data through CAT5 cable, along with using small, low cost DC/DC converters to distribute the power to the remote strips. I was able to control a full 5 meter roll of NeoPixels through 100 feet of CAT5 using the technique, more than enough for my project.

You can check out all the gory details at http://www.teknynja.com/2014/02/driving ... -over.html

Thank you to all of you for your excellent blog and forum posts, without which my lurking (and learning) would not be possible!

[adafruit_support_mike]

Thank you for posting.. a lot of people have been interested in using NeoPixels over large distances, and we like to have all the reference designs we can for tricky projects like that.

[pburgess]

Nobel Prize for awesome. Thank you!

[Cmpenney]

Could you use this technique to daisy chain the strings together? I would like to use to 14 of the 8 pixel strips to light up fence pillars. They are each about 20 cable feet apart from each other. Could you use another of the SN75176 on the output of the strip to send the signal on the next strip and so on?

[Cmpenney]

It appears that yes you can. I even did it using RGB cable instead of Cat 5 Cable.

http://youtu.be/cXr2QgqltjY

[binko]

I really appreciate this writeup - I will be attempting this solution in my boat-lighting project.

I am planning on sending 12V down one pair, the NeoPixel signal down a second, and a straight PWM signal (for a high-intensity LED) down a third. Am I right that you don't really need to send the clean 12V down the wire three times (just to re-join them at the far side)? Can I get away with one pair carrying the 12V? Or perhaps 2?

Thanks
Bill

[mh512]

Thank you for this excellent thread.

I've tried folowing this method with one strip only as a starter but not having much luck unfortunately.

The strip simply doesn't light at all and I'm wondering if anyone would be willing to help as to where I'm going wrong?

I've used the wiring diagram in the blog post with a few key differences:

* The strips are powered locally with 5V adapters (no 12V down the wire)
* Because I'm only driving one strip at present, only the following pins of the SN75174 are connected:



Would this be causing any issues and what is the purpose of the 4.7K R between VCC and the Enable pin?

Any help would be much appreciated.

Thanks
Max