Question for WS2812 Strip Users

[dariansdad]

I recently acquired a couple of these. Upon opening the package, I am under the impression that these are WS2812 strips.
I have confirmed the LED order to be GRB, and I’ve confirmed the WS2811 chip with my TinyPix controller setup software.

Now to the weird stuff that I am having a problem with.

Upon first test mode using a red chase with tail trailing, the pixels lit from the last pixel and chased to the first, against the direction of the arrows. That part was easily fixed by going back to the software for the TinyPix and reversed the strip.

I then noticed that only part of the strip was lighting. After scratching my head for a few minutes and trying to make heads or tails of my predicament,

I went back into the software and read the info for the controller. All looked as though it should, GRB, Reversed and 50 pixels activated. I then reset the controller to 150 pixels, wrote that to the controller and re-started the test mode. Now everything lit up all the way to the end and, each RGB module lit up individually as opposed to lighting up 3 RGB modules at a time, as I was expecting.

I then loaded up a sequence, now mind you, this sequence was for a 16 leg x 50 pixel tree. I had the strip on the first universe, still on the roll it came packaged on and everything seemed to work as it should on the first leg. I have not confirmed if it used the commands from the first leg of the sequence or the first 3 legs (150) pixels.

With all that said, do all WS2812 strips have this behavior and will each strip take up almost an entire universe? If so, I’ll need a controller for each strip, which seems like overkill to me, but I’m new to the 2812 package. All of my research this year has been for WS2811.

Any thoughts or comments?

Thanks,
Ron

 

[AAH]

No comment on the rgb order as that can vary dependant on the manufacturer and I know absolutely nothing about the TinyPix but strips I can tell you a bit about. Each of the leds that you can see on a strip will contain 3 leds/channels usually and the strips are generally 5m long. To work out the number of channels that a given strip has you need to look at the specs of the strip. Usually on a Ray Wu page for instance it will say 30 leds/m (30 IC's/m) or 60 leds/m (60 IC's/m). This equates to 90 channels per meter or 180 per meter. With a universe being 512 channels and 510 being usable with RGB pixel devices you will gobble channels and universes up very fast. Hope that has made things clear as mud.

 

[dariansdad]

I think I posted the wrong link. the attached is the only documentation I received. These strips are new but un-used.
If what I'm finding outis correct, these have 30 IC/M and that would equate to 150 pixels and 150 RGB channels per 5m strip. If this is correct, I'm looking at almost a full universe per strip. Am I understanding this correctly?

 

[jcmarksafb]

You are right. 1 universe can only control up to 170 rgb channels/pixels. You can span universes, but that would only pick up 20 pixels per universes. I know nothing about the tinypix, but it sounds like it only controls one universe. There are a ton of controller boards out there that can handle anywhere from 8 universes to 32 universes and all are in the $100 to $200 range.
Hope this helps
John

 

[dariansdad]

I have a Sandevices E6804 but for 2 strips, it would be overkill. I'll just order a couple more of the single universe controllers and go that way. Thanks for the replies guys. Much appreciated.

 

[fasteddy]

Using any of the 2812b with the chip inbuilt to the LED will be 3 channels per light and run at 5vdc. So a 30 LED/M strip will take 450 channels, so yes nearly a whole universe. This is why it is much better value to use a controller like a J1sys, sandevices or Advatek that have multiple outputs and can control multiple universes of data when running multiple strip like this.

Now 2811 and 2812 and 2812B use the same protocol for communications, the difference is that the 2812 and 2812b have the IC built into the LED package. The difference between the 2812 and the 2812b is that the 2812b is a later version of the 2812 that includes reverse polarity potection and a more efficient LED driver circuit.