Odd issue

[Baf05]

Today I took delivery of my order from Ray, one of the items was, LED digital module,WS2811IC 5050 3LEDSC12V input,waterproof,20pcs a string;256 gray scale . This is the exact same thing I ordered last year.

I am in the process of rebuilding my candy canes with these pixels as the are brighter, I also thought I would add a couple of canes too.

In the process I fried a couple of pixels, so needed to replace them.

I took the new ones and placed them in the cane they ended up being the first three, with 5 more of the old ones placed after in the string.

The old ones didn't work, I fiddled and stuffed about, found that the old 5 pixels were all still good, so I pretty much just made the last cane with 8 new pixels.

But, first they are the wrong white, more a warm white than a bright white of the other, now that's not a big issue, in the dark I am sure only I will notice (and pull out just one hair each time), but the odd issue is this.

The new pixels will accept data from the old, and work. But the will not send data to the old. If the new pixel can is at the end of the string, it works fine, place it at the start, or in any place it has to send the data on, every thing works until the last pixel in the new cane.

Ideas anybody?

 

[ԆцряєсϮ]

Sounds to me like they may have used different chips.


I ordered 50 WS2811s chips from a supplier in China only to find that they wouldnt work. (I only tried them feeding off an existing light string)
Got a refund and ordered from a different supplier and all were good.
The Thing I noticed was they were both WS2811 Chips but had a different Suffix on the chip.
Not having them in front of me but I think one was WS2811B and one was WS2811F.
I wonder now if I try the ones that didnt work as the first in the line whether they may now work?

 

[ltay13]

I would agree they are probably slightly different chips. Each chip completely regenerates the signal it gets onto it's data output (minus the data meant for itself). So if the chip has enough tolerance to understand the data being sent to it - it will turn on properly, but regenerate the data according to it's own exact spec. That doesn't now mean that the original chip has the tolerance to understand this newly generated (slightly different) signal.


There are heaps of chips that have very similar timing but are not actually identical. In fact even WS2811/WS2812/WS2812B are all slightly different in their specification. So it makes sense that if you mix them they may not always communicate with each other in any order you put them.

 

[fasteddy]

This has been one of the issues with our hobby. Quality and consistancy vary from batch to batch and there are differences in quality of the Chip and also the LED output and colour mixing. But in the end we are paying bottom dollar for these so Quality and consistancy is not the highest priority. Cost is for most of us.

 

[Baf05]

In the end it was too much for mu OCD to handle, so I removed the first lot of leds, and replaced them all with the new ones. I will use the olds ones for a different part of my display.

Fixed the white issue too!

They do look pretty much identical, perhaps the chip is a little smaller on the new ones, and on closer inspection the old ones have something written on the back, (that with out the aid of a microscope I have no hope of reading) then the new ones seem to be missing.