This is my first post here, so bear with me if I leave out any important information that you guys might need to know!
This is my second year doing a light show and I'm having some really strange problems with my WS2811 pixels. They just keep failing at a very high rate of several per day. Most of the failures involve a pixel completely dying and not passing any data on to any of the rest of the pixels in the strand. A few of the failures have been where the pixel still passes data on perfectly and the red and green LEDs work fine, but the blue LED in that particular pixel is stuck on (it's always the blue one for some reason). The first problem is much more severe than the second one, but it would be nice to fix them both. I keep on splicing out the bad pixel (and the one before it) and replacing them with new ones, but other pixels just keep on failing and I've probably replaced at least 50 of them so far. I'm not really sure what's happening here because everything worked perfectly last year without a single pixel ever dying. The only thing that I've changed from last year to this year is upgrading the wire from my terrible solution of twisting three 24 gauge hookup wires together from last year (don't judge me too hard for that; I'm a broke college student and I was just using what I had) to some much better 18 gauge three conductor wire, but I can't think of any reason why that would be causing the issues. And by the way, I'm using an F16V3 controller in case that matters. I'm getting pretty concerned that I'm just going to have to cancel my show for this year if things keep on dying, so I would really appreciate some help with this!
Here are the things I've tried so far (with no success):
- Adding a 330 ohm resistor to the data line of each channel right as it goes into the start of the pixel strand.
- Turning down the power supply voltage from 12V to 8V (the terrible wire from last year was dropping the voltage to 8-ish volts by the time it reached the lights, so I wanted to replicate that with the new wire to see if that was somehow the problem).
- Checking the pixels for signs of water damage. They're sealed very well in a block of epoxy, so I don't think that water or humidity is the culprit.
- Checking the power supply for excessive ripple with my oscilloscope. Things look totally fine there.
- Probing the data signal with the oscilloscope. The voltage looks a little high (the scope says that the max is around 5.6-5.8V, depending on the channel) but I don't see why this would have changed from last year given that I'm using the exact same controller.
- I've tried to see if there's a pattern when it comes to the pixels failing (like it always being the first one in a strand or something). It seems to be completely random.
And here are some links to the parts I've used that I think could be relevant to the issue:
Thanks for reading and please let me know if you guys have any suggestions!
Alex
Bookmarks