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Neopixel 30 RGBW LED Strip not Lighting Up
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Please be positive and constructive with your questions and comments.

Neopixel 30 RGBW LED Strip not Lighting Up

by jazzman1967 on Sun Jan 12, 2020 12:09 am

I bought the Neopixel RGBW strip with 30 LEDs per meter. (Product ID 2835). I am having difficulty getting it to light up. I didn't have a 1,000 µF capacitor. So I put 5 220 µF capacitors in Parallel. This brought me up to 1,100 µF. I started out with a 220 Ω & a 330 Ω resistor (a total of 550 Ω) on the data line. I initially had a 2 meter strip and checked the end connection, but I was only getting 2V to 3V. I only had a 2A 5 volt power adaptor. So I thought maybe I was trying to drive too many LEDs. I cut the strip to only have 30 LEDs. Now I get ~5 volts at the end. But all that ever happens is the first LEDs lights up a faint blue. Nothing else lights up. I don't see any issues in the circuit and I even tried just a basic test program:

#include <Adafruit_NeoPixel.h>

#define PIN 6
#define N_LEDS 30

Adafruit_NeoPixel strip = Adafruit_NeoPixel(N_LEDS, PIN, NEO_GRBW + NEO_KHZ800);

void setup() {
// put your setup code here, to run once:
strip.begin();

}

void loop() {
// put your main code here, to run repeatedly:
chase(strip.Color(255,0,0));
chase(strip.Color(0,255,0));
chase(strip.Color(0,0,255));
}

static void chase(uint32_t c) {
for(uint16_t i = 0;i<strip.numPixels()+4;i++) {
strip.setPixelColor(i,c);
strip.setPixelColor(i-4,c);
strip.show();
delay(1000);
}
}

Still nothing.

Any ideas where I have gone wrong here?
Attachments
Neopixel Connection Reduced.jpg
Neopixel soldering
Neopixel Connection Reduced.jpg (890.29 KiB) Viewed 55 times
Breadboard Reduced.jpg
Breadboard connections
Breadboard Reduced.jpg (826.72 KiB) Viewed 55 times
Arduino Connection Reduced.jpg
Arduino Pin Connection GND and PWM 6
Arduino Connection Reduced.jpg (848.7 KiB) Viewed 55 times

jazzman1967
 
Posts: 5
Joined: Sat Jun 22, 2019 2:23 pm

Re: Neopixel 30 RGBW LED Strip not Lighting Up

by kcl1s on Sun Jan 12, 2020 7:49 am

What pin does the red wire in your photo go to on the Uno? Make sure you have a common ground between the Uno and supply if you are using a separate power supply. Can you show the power supply connections too?

Fellow hobbyist
Keith

kcl1s
 
Posts: 1511
Joined: Tue Aug 30, 2016 12:06 pm

Re: Neopixel 30 RGBW LED Strip not Lighting Up

by adafruit_support_bill on Sun Jan 12, 2020 8:42 am

Connect the data line directly from the Arduino to the pixels. A termination resistor is only needed for longer runs. And the resistors on your photo are not serving any purpose at all in that position. In order to act as a termination resistor, the resistor needs to be connected at the end of the wire closest to the pixels as described here: https://learn.adafruit.com/adafruit-neo ... -practices

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Joined: Sat Feb 07, 2009 10:11 am

Please be positive and constructive with your questions and comments.