Hi, I just recently got a strip of WS2812B LEDs and have been trying to get them up and running with the FastLED library, however I’ve been having an issue with a section of them flashing white. I’m guessing it’s an issue with the LEDs themselves however I’m just wondering if anyone else has had similar issues before and if there’s likely to be anything I can do to resolve it, or if i’ll just have to give up on that segment?
It’s a strip of 60 leds, first 15 work fine, second 15 toggle between white and black each time FastLED.show() is called, then the remaining 30 LEDs work fine. If anyone has suggestions for what might be causing the issue then let me know. Cheers.
Sounds like it could be the LED’s, however set the brightness really low and try it again. If they’re solid, then you have power issues. Oh, and it never hurts to post your code to http://pastebin.com and to describe your circuitry in detail.
Thanks for the suggestion Andrew. Unfortunately, even at near 0 brightness the 15 LEDs lit up as full bright white every second time FastLED.show is called.
I realized that the LEDs were appearing to work fine on every odd time it was called, so I tried replacing FastLED.show() with two calls to the function, after which things started going crazy and the section of 15 full white LEDs started moving up and down the strip… which made me a bit concerned.
I’m currently just testing with the FirstLight example, and standard circuit, just with a 220 Ohm resistor on the input pin from my Arduino Uno.
Oh, and I’m using a 5V 3A power supply, grounded on both the Uno and the power supply ground lines. Tested on two different Uno’s with the same results.
You could try without the 220 ohm resistor, or add a 10K ohm resistor to ground. . . Maybe a 1000uf capacitor between Vcc and ground. Let’s see what others have to say.
Thanks again for the suggestions Andrew. Still no luck unfortunately… at this point I think I’m just going to have to give up on this strip and order a new one…
Don’t give up on the whole strip. Cut out the bad section, solder the ends of the two good sections together and you have a 45 LED strip. That will also let you double check that that another 15 don’t go weird on your ‘new’ 45-LED strip, and lets you trouble shoot the 15 troublesome ones on their own.
Great recommendation allan. I’ve got several short strips that have been liberated from the potential death pile. They make for excellent test beds or smaller displays, like Chinese lanterns.