Did I just kill my Neopixel Arduino shield?

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

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mjm
 
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Did I just kill my Neopixel Arduino shield?

Post by mjm »

Initially I had my shield attached to an Arduino Uno. Running the strandtest went fine. Then I proceeded to solder on the header for external power, I cut the jumper and attached the shield's Din pin to a Spark Core. I used the https://github.com/technobly/SparkCore-NeoPixel library which is derived from the Adafruit library.
This setup yielded a colorful, but seemingly random color display. I suspected a programming error, or maybe the fact that the Spark Core has 3,3 V logic and I didn't have a level convertor (people have reported success however).
Reattaching the shield to the Arduino didn't help: all pixels are dead?!

What I didn't do was use a capacitor and resistor as per Adafruit instructions. Naively I thought that this would be handled by the shield (stupid, yes). I verified that the shield gets 5 V.
I noticed that when I attach the power some pixels will light up shortly.

Any tips on troubleshooting, salvaging?

TIA

Marcel

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adafruit_support_bill
 
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Re: Did I just kill my Neopixel Arduino shield?

Post by adafruit_support_bill »

I don't know much about the Spark Core. 3.3v control signals are sort of marginal for the shield. Sometimes they work, sometimes not. The 'official' logic threshold for 5v powered Neopixels is 3.5v.

In any case, your symptoms sound consistent with a dead pixel. Often this is confined to the first pixel or two. If you feed a signal to the input of the second pixel, you may find that the rest of the board is fine. If you are handy with a soldering iron, we do have replacement pixel chips. (check your shield carefully, there are 4 and 6-pin versions of this chip).
http://www.adafruit.com/products/1655
http://www.adafruit.com/products/1379

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