Newbie seeks some assistance

Good day, I recently discovered Pixelblaze and wanted to play around a bit with it and see if I could make some neat art pieces etc. I like to paint (so to speak) with light and thought this would be a creative way to test ideas etc.

So I purchased a Pixelblaze some WS2811’s and a power supply.
I have read some of the getting started info and some of the other items posted.

My issue is the proper set up of the PixelBlaze for the lights I have.
I am not sure if I can post a link to the lights I purchased but if allowed it will probably assist in the fault finding steps.

I purchased ALITOVE WS2811 12mm Diffused Digital RGB LED Pixel String Light Individually Addressable Round LED Module 50pcs/String IP68 Waterproof DC 5V from , I connected the 5 vdc (6A) supply to the lights and I am using usb to power the Pixelblaze.

In the settings page I selected my Pixelblaze,
limit brightness to 50%
LED type WS2811
50 pixels
data speed 2 MHz
color order RGB

the lights stay white with a bit of color flicker, changing data speed or color order has not effect on the lights they stay bright and white with a bit of colour flicker (very faint).

If I select WS2812, the lights pulse different colours but brightness cannot be controled or patterns cannot be selected. Changing data speed will affect the lights but the result is not the patterns selected or can brightness be altered.

I know I am probably missing something simple but unsure where to look.

Any help is appreciated

You need the PB board and leds to share their ground. So what you want to do is not use usb to power the board but instead put +5 and ground into the pixel connector on the PB and then have +5v, ground, and data go to the leds. DO NOT connect the usb up and reverse power the PB from the led connector (using you 5v power supply) at the same time. Power from one of either the seperate power supply, or the usb connection but never both. Let me know if I am not explaining this clearly…

If you just have 50 pixels you can use the USB connection for power… just make sure to set the PB’s max brightness to 50% and do not do all white on the pixels at the same time.

nope got that correctly. understand that concept.
I did not have the led strip grounded to the PB I will having the external PS supply everything.

THank you

so connected all via the external PS and works better but not as expected.

If using WS2811 the strip lights up but dim and mainly white, a couple LEDs are red.
no change in data speed changed anything.
If I select buffered (x2 rate) WS2812 / Neopixel
and a data rate of 286/571 ns
and a colour order of RGB it displays the patterns correctly.

not sure what is happening there?


Can you post a picture of your setup that shows all of the connections between your PB, pixel string, and power supply?

I certainly will but will be later as I put it away for the night.
Thanks for helping out. I must say that this forum and the Hubitat forums have some great folks. very helpful indeed.

Thanks again

@wcleafs2002: Remember that WS2811 is an older chip and I believe only 1/2 as fast as the ws2812b. Try playing with the data speeds to find one that works for you. The PB gives you lots of flexibility but it may take an extra minute to get the results you want. IMHO it’s well worth it. Please keep us updated to your progress or if you still have issues.

I have been reading up on the WS2811 chip and it appears that it works at either 400 KHz or 800 KHz (800 being the more common). That is not a selection in the pull down menu. is there a way to edit the settings to add those options in data speed or a way to tell the PB that data rate?
edit, one of the articles is was reading:

I believe that those timing relate to the data rates. I have always just played with them till I get one that works, but it would be nice to actually understand them.
@jeff, @wizard, @zranger1, @Scruffynerf or any other of you peeps give us a crash course in the data rate timings pulldown in the settings menu? I tried to find some documentation on it and have not had any luck yet.


Do these lights actually do more-or-less the right thing if you set them to buffered WS2812? If so, it’s ok to just leave them set that way and run with it. Wouldn’t be the first time yet another strange LED variant has turned up under a not-quite-correct label.

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PB connection PB connection 1

here are the pics
the line with the heat shrink goes to the power supply.
PB is being fed power via the LED string.

Can you upload a larger, higher resolution version of those pics? For some reason, they got uploaded very small and fuzzy.

Much better pics!

Ok, I see a potential issue… You are powering the PB using the wires on the opposite end of the string, which may be creating a slight but critical ground-reference problem with the data line which is connected to the first pixel and therefore referenced to the ground at the first pixel. In other words, the ground voltage at the two opposite ends of the string may be different enough to cause a problem.

Try powering the PB directly from the power supply at the same point that the first pixel in the string is connected.

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roger that will try that and let you know, thanks for the suggestion.