Flickering led strip (SOLVED)
ey guys!
I have a little problem and I am sure some of you faced this already and have some tricks.
I am driving 8 led strips 2 meters each. WS2812b. all of them are connected to arduino digital pins with very short cables. All the grounds are connected. I am using only one power supply, so the gnds from the boards + the gnds from all led strips are connected and tested. Yet, I still have some grounds related flickering.
how can avoid this annoying phenomena?
I did an awful little video in case somebody wants to see. there are 3 led strips that are flickering normally. specially the one on the inferior left side of the shot.
Are the strips powered separately? Or from the Arduino?
Have you tried disconnecting a couple of the “good” strips to see if the blinking one settles down?
they are powered from the power supply
I just had the same problem about a week ago. One strip out of a bunch was blinking erratically whenever (and only when) it switched to white – even though it was getting the signal from a strip in front of it, which was working perfectly. The problem, for me, was that I was supplying just a little too much voltage to the flickering strip. I was supplying about 5.2V to that one strip. When I dropped it to 4.8V, it fixed it right away.
Also, do you have a resistor between the signal pin and the strip? I haven’t experienced it myself (maybe because I always use the resistors), but apparently that can make a difference.
I almost never use resistors… what value do you use for ws2812b and ws2811?
I am also going to measure voltage on all 8 strips, but I am expecting to have the same values everywhere, since there is barely a difference between their connections.
no voltage difference between the strips (4.5V ± )
But I have just noticed something very interesting. when the flickering occurs, it happens along the whole strip, except for the first pixel. the same in all 3 strips. it seems I could have a first broken pixel…
I’ve read between 220ohm and 470ohm can be used. I tend to go middle of the road with 330. There’s probably a way to calculate the optimum value based on voltages and/or strip length and/or signal wire length, but that’s out of my league!
Another thought… have you tried swapping the signal pins to see if the problem is connected to the strip or the output?
A first broken pixel in three strips would be odd… unless there was an “incident” the other ones survived.
How do you connect the actual end of the strip to your wiring? Some kind of clip, or soldered connections?
it seems to be the strip. as I said, when the flickering occurs, it happens along the whole strip, except for the first pixel. the same in all 3 strips. it seems I could have a first broken pixel… It wouldn´t be the first time I see this. I should have remembered.
I am going to put a resistor and see what happens and if It doesnt get better, I will cut this first pixel.
coming back in 10 minutes with results
adding a resistor (470ohm) improved the situation, but it did not sort it out completely. the flickering was reduced but didnt dissapear 100%.
Now, removing the first pixel sorted out the problem for good.
The strips are all recycled from another project. this means that I soldered the connector 2 or 3 times in those strips. This first broken pixel then doesnt surprise me now… What it does surprise me is that I dont remember about these things!
I will anyway have in mind the resistor fact, and never again mount my projects without resistors. (if I remember… :))
Thanks @allanGEE for you support!
Honestly… at my terribly low level of expertise… if I managed to help you I’m probably feeling happier than YOU are about the results.
All the best with your project!
sometimes, the only thing you need to realize about something, is an external input, that triggers considerations that would have been otherwise overlooked.