Curtain color issues and flickering

I have a ws2812b curtain 20x20 pixels. Brand: TNALANT. The curtain has sub modules on top.

ESP32 with SoundReactive version 0.13.4.

I use a 74HCT245 al inputs to ground. And I currently have a 100Ohm resistor in the signal line. Also tried 330ohm. I use a 20amp 5 volt power supply. Length to curtain is 30cm. With 10cm same result.

The Curtain on Ali Express (sorry dutch site)

  • When in solid red, every strand is red, green or blue. The color changes every two or three strands.
  • When i make is 1x1 and skip pixels by 20 it moves to the next strand, only the color changes from red to green. The more pixels i skip, the more random leds light up. Sometimes even flashing inside the subcontroler box ?!?!?
  • When lightening only 20 pixels, the color in the first strand is correct. Other strands do light up and flicker.
  • My setups all work fine with 100 led feary lights and neon led strips.
  • The original controler also works fine.
  • I have switched WLED controllers, same result.
  • I tried different types of strips in settings, no improvement, sometimes crashing WLED.
  • I have switched the Data, + and -. However in this configuration the effects work, only colors are messed up and flashing brightnes.

Any ideas, suggestions, or things i can try?

Try to remove data line resistor

Hi,
I have similar curtains. The “sub modules” on top are actually sacrificial LEDs to boost the data signal back to 5V every 20 LEDs.
The little USB controllers, that come with the curtains, have specific code written to ignore the 1st and every 21st LED. I don’t believe that WLED can ignore that many LEDs (max 16 segments).

I have an ESP32 on order and intend to use it for my existing curtains (4 of them).

My theory, for your fix, is to open each one of the subs and bridge the LEDs input/output by soldering a little wire jumper across it from the data-in to the data-out (mind you, this means that you will need to add more injection points along the curtain).
Put some non-acid silicon in the subs to waterproof before you close them up again.
You will notice that the sub at the top of the last string does not have an LED inside.

Good luck. :sunglasses:
Let us know how you go.
Regards, Leigh.

1 Like

Thanks, i thought about something like that. I do think there is more to it.

Why do the the sacrificial leds do not always turn on in every strand? If I set it to solid 20x20 I would expect all sacrificial leds to turn on. However none do.

If I configure wled to show 50 pixels, only one lights up flashing. So maybe they are not in all of the ‘sub modules’. Just every few strands.

How does this explain the color shift every few strands when set to solid red? I get the feeling it sometimes strips of, or add a byte ot the RGB, so it shifts from red to green, and from freen to blue.

If the curtain is 20 x 21 (minus last strand), a custom map might do the trick?

They contain a chip that strips of 20/21 leds (assumption). This is a photo in the last module.

Then I still have the flashing and other weird behaviour. This might be something else though. I will focus on the colors first. I think I need to open all of the sub modules…

Thanks, I started without any resistors. I’ve used this setup(s) for many projects without issues. There might still be something wrong with the setup in relation to the large number of leds. Usually I had 100 led strands max.

Ok I just put wled in strip mode with 50 leds solid red and this is the result:

  • The sacrificial led in the 3rd sub module is on (flashing showly). The color keeps matching the 1ste strand color.
  • In the first 3 strands 50 leds are on plus the red led flashing in the 3rd strand
  • 8 leds in the 4th strand
  • 5 in the 5th strand
  • 3 in the 6th strand

This is with 100 leds solid red:

The sacrificial led in the 3d column is off. The led in the 5th column sub module is flashing red/green in the same order as the 6th column changes to the same color.

Somehow I have a feeling that there is a pattern in this madness.

Still I think it is weird that the colors change per whole column (in solid). And they do change colors from red to green etc. Something s shifting the colors.

Oh and with 150 led’s no led’s in the sub modules are on.

All submodules have a led smd’ed on it (also the last one, I checked). I do not understand why it have to be led’s, because there are other ways to bump the signal back to 5V that do not produce light that you have to exclude?

Can it be that In the protocol they send one byte extra every few strands?

Hi Randy,
Your subs are much better quality than mine. Mine are so cheap (probably why they use an only LED to boost the data signal)

My subs are nowhere near waterproof. After light rain I get strange colours showing in random strings (and the sub lights up). I got strings 1-11 working fine. 12 was all wrong colours (sub light up). And strings 13-20 were ON but unresponsive to any colour changes (data just not getting through)
One day I measured the V+ at the bottom of one of the wrong colour strings (I pushed a pin up the unsealed end of the V+ & GND wires and attached my multimeter). I found it was only around 3V where the other good strings were 4.5V. Moisture or condensation may have been dragging the voltage down or the USB stick may have failed somehow. Then miraculously a few hours later all the strings were good again.

Sorry, I’m not much help to you at the moment. I’m just sharing my similar experience hoping we stumble across an answer.
When I finally get my ESP32, I’ll see what I can do to make WLED control the curtain.

Regards, Leigh

I have 3 curtains, 2 1x1 meter and 1 3x3 meter. Now i just installed the second 1x1. The difference is that this one does light up the led’s in the divider. However they seem to be row 21… see picture.

I will try to hook up this one on WLED and see if there is a difference…