RS485 Serial Server, PC to WS2812B

Greetings, I’m new and just installed my first WS2812B strips. The issue I’m running into is I have a front part of the house that is wired up and if I mount a UNO board in the attic, its more than 15 feet away and doesn’t work. The other strips work with no issues (initial length is less than 15 feet).
I worked in RS485 RFID industry previously and have lots of RS485 converters (from RS232-serial port) and even a digi connect serial server (ethernet on one side and then connect to a 9 pin port connector for the MSTP wiring. Is there a way to modify the software so I can send the data pulses by RS485 using WLED versus having to run from a UNO or arduino board? The RS485 can go up to 1200 m with no issues. Thanks for any advice.

If the run is not working need to check wire. It should do 15ft with no issue. Aka wire size, connections, and possibly need more power.

No you can’t convert to rs485 without possibly some extra electronics and experimentation. It would not function natively. Love the idea. In fact some of the expansion modules on fancy controllers do something like this.

I thought @Quindor did some testing and found that he could go much further that that when using a level shifter.

Yeah, that won’t map out well.

First off, using a level-shifter to go from 3.3v to 5v for the data signal should make 15 feet for the data wire no problem at all.

Second, the LEDs use a very specifically timed (clockless, so timing is VERY critical) 800kHz signal, I don’t see a decent way to convert that to RS485 and back and still work. It would also involve a lot more hardware really. A level-shifter should solve this issue I believe.

You can also try a sacrificial pixel or F-Amp, they all do the same thing.

485 can go up to 10 megabits per second.

It has been done before with RS485 using limited Hardware: https://www.teknynja.com/2014/02/driving-ws2812neopixels-rgb-leds-over.html?m=1

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Another option might be to add another DigUno and sync the two DigUnos together. This is simpler than trying to coerce pixel data into and out of a rs485 gateway you would have to cobble together and make work.

After you get that 2nd DigUno synced, you can then try to make your own rs485 gateway. You would spend more money but you might enjoy it more :slight_smile:

There are some max485 TTL to RS485 differential convertors for cheap that I am going to try. They support up to 2.5Mbps so 800kbps should be just fine. Just need a pair and a 12V to 5V convertor if you are using 12V lights. I have been able to run 35’ from the controller to the first led segment without issue but that is about it…I tried 50’ and it was no go. With RS485 you should be able to run 1000m without issue…

I have just tested this using the following TTL to RS485 modules and it works brilliantly. Use ethernet cables to interconnect the data and the 5V for the remote end. These 5V converters are total overkill but is what I had on hand. Zero other components. :slight_smile:

Diagram
TTL to RS485 using MAX485 Chip
5V DC to DC regulated PS

Thanks. That is awesome! I appreciate it.