Neopixels - individual ones not working

EL Wire/Tape/Panels, LEDs, pixels and strips, LCDs and TFTs, etc products from Adafruit

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carl_tt
 
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Joined: Thu Sep 05, 2013 10:12 pm

Neopixels - individual ones not working

Post by carl_tt »

I recently got the following product: 1376 Adafruit NeoPixel Digital RGB LED Weatherproof Strip 30 LED.

I wired it up using an Adafruit 5V, 10A power supply (just received), and an Arduino Mega. It was on a table, and all worked fine. The next day, it did not seem to be working. Using a logic probe, I found that the power lines were fine, but the data was not making it through the first LED. I connected the control wire to the solder pad between the first and second LEDs, and it worked up to about the 30th LED, and I presume that one is out too - did not test further yet.

I read a bunch of the forum posts, and it sort of seems like over voltage since it was the first LED, but I am assuming the power supply is OK? I do not have an oscilloscope to test it. I can say that the power supply was plugged in the whole time - was just plugging the jack into the terminal connector.

I tried jiggling the LEDs a bit since the 30th LED was also out, but that did not seem to help. Not very conclusive, though. I stopped at taking it apart and looking for soldering issues etc.

So, I would like to know if this is a typical issue, or more likely a defective product? I am thinking of using this kind of strip or LED pixel strands for outside holiday house lighting, so reliability is desirable. :-)

One more note: A friend ordered the same setup - strip, power adapter etc. and had the same issue - the first LED seems to be out.

Thanks.

EternalCore
 
Posts: 239
Joined: Tue Jul 30, 2013 3:57 pm

Re: Neopixels - individual ones not working

Post by EternalCore »

As with lots of Electronics I don't recommend having power going through the strand for a whole night without the strand being used; As Shorts, power-spikes can and do happen more often then not... But To stabilize the strand and pixels put a 2nd ground wire to the ground of the Arduino. See if that works then report back.

carl_tt
 
Posts: 4
Joined: Thu Sep 05, 2013 10:12 pm

Re: Neopixels - individual ones not working

Post by carl_tt »

Yup - I did not leave it plugged in - meant that I disconnected the 2.1mm DC plug, as opposed to unplugging the power supply.

I always had the ground shared with the Arduino - it works fine after that first one, and before the ~30th one...

Thanks.

EternalCore
 
Posts: 239
Joined: Tue Jul 30, 2013 3:57 pm

Re: Neopixels - individual ones not working

Post by EternalCore »

hmmm weird... Can you post pictures of how you wired it up and of those pixels that aren't working.

carl_tt
 
Posts: 4
Joined: Thu Sep 05, 2013 10:12 pm

Re: Neopixels - individual ones not working

Post by carl_tt »

OK, the 30th one was my fault - had added that in the code when testing and forgot. So the first LED is still an issue, and sounding more like a power issue. I am not sure how my friend had the same issue with an independent set of parts. Pictures attached.
P1070287v2.jpg
P1070287v2.jpg (409.62 KiB) Viewed 363 times
P1070288v2.jpg
P1070288v2.jpg (476.59 KiB) Viewed 363 times

carl_tt
 
Posts: 4
Joined: Thu Sep 05, 2013 10:12 pm

Re: Neopixels - individual ones not working

Post by carl_tt »

It's probably worth saying that sticking the signal wire on the pads before the first LED does not work either. Also, the whole strand worked as expected the night before.

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