Guidance for large Neopixel installation please

Projects
#1

I have attended several VHS Neopixel workshops over the years and am about to embark on a large scale project (at least large for me!!). I would welcome some guidance please.

The installation will have 50m of WS2812B Neopixel LEDs made up of 10x 5m reels with 60 LEDs/m. In total that is 3,000 LEDs.

All 10 5m strips will be connected in serial, with each 5m strip powered by a 12V 6A supply via a power tap kit.

Q1) The lights will be controlled by a RPi4. Is the data signal from the RPi strong enough to travel 50m?

Q2) Each PSU is 12VDC x 6A = 72W… and mains is 120VAC x 15A = 1800W. Is it safe to assume I will have no problem running all 10 PSUs off the same circuit?

Q3) Any recommendations where I can purchase 50m of good quality/good value LEDs?

What have I missed?

Thank you very much for your advice.

Kind Regards
Ian

3 Likes
#2

Some questions and thoughts.

  1. What is the distance from the controller to the first pixel and is there any appreciable distance between the strips? And what are you usign the drive the pixels from the Rasp Pi? Make sure you use a level translator (as the Pi uses 3.3v logic I think but the pixels really like a 5V signal). I have used SN74AHCT125N for this purpose.
  2. Typically pixels max current draw is 60 mA (0.060 A) allowing for full white (all LEDs on full). Max current draw with 3000 pixels could be close to 180 A. You may need more power supplies and a single outlet may not be enough. Now in reality newer pixels seem to draw less power than 60 mA and you will not normally run your pixels on all white at max brightness.
  3. I have bought pixels from various vendors on AliExpress. It does seem a crap shoot for quality sometimes but BTF seems to be ok (also used Ray Wu). Just buy lots of extras.

Couple other things that may help:
Pixels do crap out so try to design your display in a modular fashion with a way to replace strips
Pixels draw a lot of power, make sure you use sufficient wiring for the power leads
I made up this pixel presentation just as COVID hit but it may have some helpful information:

#3

@packetbob Can the RPI4 drive the WS2812bs at the right speed? I know that previous RPIs had issues with that

#4

Not sure of possible Pi limitations. I know the Xmas lighting folks have several types of Pi Hats for driving pixels directly from a Pi running Falcon Player (GitHub - FalconChristmas/fpp: Falcon Player). The FPP controls the attached pixels via E1.31 data…

@captain_semtex - what are you running on the Pi to drive the pixels? and what version Pi?

#5

Some of the lessons learned on this project may be relevant to your project:

#6

Ian - great to see you on here and working with enough LEDs to fry everyone’s retinas. I love it. Hope to see some pics of your project when you get to that point. Cheers.

#7

Also note my math was for 5V pixels and you mentioned 12V power supplies… If you are using12V pixels your current draw may be even more as the 12V strips often use a resistor to drop the voltage to the 5V the chip needs.