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WS2812B Wiring

Thu Mar 09, 2017 9:04 am

I have a Pi 3B+ and 2 metres of WS2812B LED strips (30 LEDs per metre; Adafruit NeoPixel compatible).

The inputs on the strip are +5V (5 volts), DIN (digital in) and GND (ground)

What are my wiring options, and can the strip and the Pi share the same power source?

Thanks in advance :)

Posts: 351
Joined: Thu Mar 28, 2013 9:19 am
Location: Nottingham, UK

Re: WS2812B Wiring

Thu Mar 09, 2017 12:05 pm

Well, I wouldn't.
Use separate supplies, since the LEDs can take quite a bit of power at fully on, and you have 60 of them. If the PSU is suddenly unable to supply 5V and sufficient current to your Pi, the Pi will "fail" and may corrupt the SD card. Don't go there.

In addition, you might find that the GPIO is underpowered to drive the first LED, since the DIN is a 5V level, and the Pi is only 3v3.
If you look on the Adafruit site, I think they show how to connect everything together, but the LEDs are picky about timing, and Linux is not :(
Steve S
No, I can't think of anything funny that won't offend someone if they want it to...

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Joined: Thu Feb 05, 2015 11:25 pm

Re: WS2812B Wiring

Thu Mar 09, 2017 12:18 pm

I've a few of these strips (30 led/m versions) and pin12 on a Pi drives them no problem

On two of them - I do power them via Pi pin2 but deliberately don't use full brightness (and/or only light alternate LEDS)

On the bright strip where I use 100% - I have an 10A PSU and I split it so that + and - separately feed to my Pi and the strip (and don't forget to connect the gnd from the strip to the Pi as well of course)

each R/G/B colour on each LED approx takes 20ma so can also "cheat" by altering brightness levels depending on colour being displayed - e.g for red/green/blue - turn it up yellow/cyan/magenta (as they use 2 RGB colours)- turn it down - white (whic is all 3 RGB) - turn it right down

Posts: 2
Joined: Thu Mar 09, 2017 8:57 am
Contact: Website

Re: WS2812B Wiring

Fri Mar 10, 2017 1:00 am

Thank you.
I think I'm gonna just use external power.
Does a phone charger give enough power to drive the strips?

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