Controlling single colour LED strip with WS2811/WS2812

Support
#1

I am planning to use my new BlinkStick Pro to control the internal lighting in my PC case (and maybe do some ambient monitor backlighting down the line too).

I’m hoping to use WS2812B RGB strips to create different lighting effects within the case, but I also want to think about adding some white strips and maybe even some individual LEDs.

My main question is how can I have my BlinkStick control the brightness of the dumb LEDs whilst also controlling the addressable pixels.

One idea I have is to connect all the dumb LEDs as one pixel using a WS2811 controller, though I’m not sure how best to provide enough power to the LEDs being controlled by the chip.

Something like this:

Alternatively…
Perhaps a more efficient way of doing it would be to reprogram BlinkStick’s firmware to enable using a spare pin to send out a PWM signal, and control the single colour brightness that way.

I haven’t looked at the code yet, but it may be difficult (using pretty code, anyway) to enable WS2812 mode and PWM at the same time, plus this would limit me to 128 addressable LEDs…

Since I’m pretty inexperienced in electrics and new to the blinkstick codebase too, I’d appreciate any help or suggestions!

-Matt

#2

Hi @matt and welcome to the forums! Probably the easiest way to go is to have multiple BlinkStick Pros connected to your computer. Client application supports any number of BlinkSticks connected and can control each individual pixel on WS2812B LED strips. Same applies to API implementations if you want to control BlinkSticks yourself.

You will probably want to use the internal power supply of your PC case to power up the LEDs, but make sure that it’s capable to supply the required current.

As far as mixing basic LEDs and WS2812 on the same BlinkStick Pro it is possible, but could be a bit complicated and not sure if it would be worth the time :smiley:

#3

Thanks @arvydas for the welcome and fast response.

So lets say I forget about having both types of LED on one BlinkStick and get a second one, you are suggesting that I should hook up a PWM LED controller via SATA or Molex and then have blinkstick output a PWM signal to the controller?

Connecting to the PSU is fine as I have the connectors, but being inexperienced I still have a few questions;

  • Is there anything in the API related to PWM?
  • If I power LEDs/LED dimmer off the PSU can blinkstick still control the brightness?
  • Will there be any complications with earthing if the LEDs/PWM dimmer is powered by the PSU but controlled by blinkstick?
  • Do you know of any suitable PWM dimmers designed for LEDs?
  • Finally, is blinkstick overkill for outputting a PWM signal? Fan headers on a motherboard can often do this, otherwise there may be cheaper/more basic alternatives?

Many thanks once again!

#4

I would suggest Molex as they are easier to assemble.

Yes, BlinkStick Pro can operate in mode 0 or 1 for PWM. Then R, G and B pins become PWM outputs and you can control the whole LED strip with single color. These LED strips are very common and you can light up the whole LED strip with a single color only. I would recommend an LED adapter board because it already has MOSFETs on it and is suitable for single color LED strip control.

In order to control the brightness of LEDs, you have to connect them through BlinkStick and MOSFETs.

No, you would have to do this in order for BlinkStick to function correctly. Grounds must be common.

Yep, LED adapter board as described above :wink:

BlinkStick was designed to drive LEDs and both client application and API implementations integrate with it. You can also use an Arduino and have pretty much the same effect, but you will have to write firmware for Arduino and your own custom software to communicate through virtual serial COM port.

#5

Ah, fortunately I’ve got one - my original plan was to use 12v RGB, but my 5050 strips were dodgy!

So just as simple as bridging BlinkStick’s and the PSU’s ground? (out of curiosity, would a higher voltage circuit grounding through blinkstick (without MOSFETs) damage things, or is it ok because ground is 0V?)

Apologies, for some reason I was thinking it was more complicated than simply flashing the LEDs directly with the PWM current… I assumed (before further research) that a chip would take the PWM signal from blinkstick and output appropriate voltage to the LEDs… Silly me! (do PWM fans/motors work the same way? 4 pin PC fans have a constant 12v supply and a separate PWM control signal, hence my confusion…)

So, just to confirm, I power the 12v Adapter Board, connect an earth pin and a signal pin to my blinkstick (no 5v VCC needed?) and then connect the LEDs to the Adapter Board.

Doing this it is theoretically possible to also connect a WS2812B strip or two in parallel with the Adapter board, directly to the BlinkStick? But doing so would require firmware modification, or just API?

I must say you’ve been very patient with me!

#6

@matt you can use a new type of ws2812 led strip that have white color very beautiful: rgbw ws2812 led strip. I bought it from Shenzhen Shining Future LED Technology Co., Ltd., very interesting.

#7

rather than WS2812B led , If your solution can support ws2812b updated version ,ws2813 led?