Neopixel strip being touchy after working for a couple of days

Having an issue with a 1m 60 LED neopixel strip. 1/3 of it will light up, and the next working LED will be green which isnt part of the code at all, then ill move it around a lot and more will light up but won’t be apart of the code it will just be red so id say about 2/3 of the strip is working. I had it working for a couple of days but now its not and connections seem fine, should i cut the first led and resolder it?

What voltage do you measure on the 5 volts at the string? How is the strip connected to the controller? Ohm things out to see if there is a broken connection. .

sorry should of included everything first, I’m not gonna lie the solder job looks kinda of flakey but it was working for a while so I just hope it’s not the lights

Had to make another post because I ran out of attachment space per post, also wanted to say that sometimes ill bend the strip a bit where the next LED isn’t turned on, and after messing with it for a couple of seconds itll work. so basically I just bend and move the strip where the LEDs stop lighting and itll work so the whole strip can function at times but sometimes itll just stay red or yellow and just stay one color instead of functioning with the code

post #2, You need to work on your soldering skills ;)

It is recommended you have ~ 470 to 1000 uF soldered at the strips terminals +5 to 0 volts. Observe polarity.

Also recommended you place a 470 ohm resistor in series with the Data pin.

Sounds like you may have an intermittent connection on the strip.

Again, what voltage are you measuring at the +5 to 0 volt input to the strip?

You should be powering the strip with an external power supply.


I have a 330 ohm 5% 1/4w carbon composition (NTE brand) would this work? I read 300-500 ohm

^I don’t understand what you mean by series, do I solder the resistor to the copper looking area of the data pin on the strip and then solder the end of the resistor to the end of the wire I have coming from the data of microcontroller? Do I splice the wire and put it in the middle? Sorry I need you to be more specific.

Also how can I observe the polarity? Multimeter?

I am using a 3.7V 2500mAh portable power supply so the voltage is 3.7V.

I also am having the same problem with another strip (like 15 LEDs light up of the 60) on a separate neopixel strip, separate battery and microcontroller. (same setup though) ill add another picture of solder job.

I am trying to daisy chain these strips together but I wanted to make sure they all work before I do.

Thanks for your help

Your resistor can be soldered to the DI foil and the data wire to the other end of the resistor.
You need 5 volts for the neopixel strip.
Make sure the GND of the external power supply is connected to the GND of the controller.

Read this:

Observe polarity.

The + on the capacitor connects to the +5 volt pin.

iirubixii: I am using a 3.7V 2500mAh portable power supply so the voltage is 3.7V.

You are using a 3.7 V power source to power a NeoPixel strip designed for 5 V and you come here and ask us why it misbehaves?

Are you kidding?

oh wow I'm derpy im surprised i didn't catch that earlier. didn't need to be such a savage tho Paul lol

Could be worse! :grinning: :grinning: :grinning:

No according to the data sheet the WS2812b LEDs will work off 3V3.

You need that large capacitor which you seem to ignore. The resistor protects the first LED only, after that the data signal is regenerated.

The fact that the bad LED is in the middle suggests a break in the PCB at the point where you would normally be able to cut it, perhaps due to too much flexing. Cut the strip here and remove the first LED then reconnect the rest of the strip.

@Grumpy_Mike yeah actually where the PCB might be broken is the point where I’ve had the strip bent at a certain angle so i’m positive this is probably what happened.

I’m going to cut the strip like suggested and reconnected through data and ground.

would the capacitor in the link above work for this? the link below says I can use over 1000 uf 6.3v or higher

would the capacitor in the link above work for this?

Yes that should be fine.

and reconnected through data and ground.

OK don't forget to remove that first LED because that is the one that could be damaged by say having a signal into it that is above its power rail, if the power rail is removed. It could also be that the last "working" LED might be faulty because it drove its output into a faulty device, so the output stage might be blown. This I think is a small possibility but it is still a possibility. It is something to try if removing that first LED is not successful.

Awesome thanks Mike!!