Noob Questions & no red on one NeoPixel

[kagatoamv]

This is my first time working with NeoPixels, and I've observed two odd things I'm hoping I can get some help investigating.

I have a 1m length of 144 Neopixels wired up to my Arduino Uno. I'm powering the strip the a 5V 2A PS I ordered from here as well, with a Cap between the pos/neg.

When I run the StrandTest, I see two weird things:

First: The 24th NeoPIxel from the end doesn't display Red. During the red color wipe of the test, it remains dark, but is vibrant during the blue and green, the colors during the rainbow effect are off as they don't have red.

Second, the last 12 NeoPixels light up fine during the colorWipe and rainbow displays, but remain static, either dark or with odd colors during any of the Chase tests.

There was already a resistor on the data line, perhaps that is corrupting the data signal toward the end?

I configured the StrandTest with the following: Adafruit_NeoPixel strip = Adafruit_NeoPixel(144, PIN, NEO_GRB + NEO_KHZ800);


Thanks for any input.
-Nic

[adafruit_support_bill]

Sounds like you have a couple of flakey pixels in that strip. If you contact [email protected] with a link to this thread we can get you a replacement.

There was already a resistor on the data line, perhaps that is corrupting the data signal toward the end?

That should not be an issue. The resistor affects only the signal to the first pixel. Each pixel acts as a signal repeater to the next pixel in the strip.

[kagatoamv]

Thanks, I'll do that.

[kagatoamv]

I received the replacement strand yesterday and everything tested out perfectly.

Thanks!