Hi all!
First time poster so please feel free to give me feedback on the clarity of my question.
I have purchased 2 sets of SK6812 Mini LEDs from 2 different suppliers for a project that I am working on. Unfortunately, both sets of LEDs are behaving in a manner that seems to contradict the datasheets that I have been provided.
This is a screenshot from a datasheet that I have been using:
This is the code I have been using (tried on both a Arduino Uno "Freetronics" knock-off and a Arduino Mega 2560)
#include <Adafruit_NeoPixel.h>
#define PIN 8
// Parameter 1 = number of pixels in strip
// Parameter 2 = pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
// NEO_KHZ800 800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
// NEO_KHZ400 400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
// NEO_GRB Pixels are wired for GRB bitstream (most NeoPixel products)
// NEO_RGB Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
Adafruit_NeoPixel strip = Adafruit_NeoPixel(2, PIN, NEO_GRB + NEO_KHZ800);
void setup() {
// put your setup code here, to run once:
strip.begin();
strip.setBrightness(10);
strip.show(); // Initialize all pixels to 'off'
}
void loop() {
// put your main code here, to run repeatedly:
strip.setPixelColor(1, strip.Color(255, 0, 0));
strip.setPixelColor(0, strip.Color(255, 0, 0));
strip.show();
delay(1000);
strip.setPixelColor(1, strip.Color(0, 255, 0));
strip.setPixelColor(0, strip.Color(0, 255, 0));
strip.show();
delay(1000);
}
I wired up a test LED according to the datasheet:
And connected it to the Uno using the guidelines given on this website for NeoPixels (Powering NeoPixels | Adafruit NeoPixel Überguide | Adafruit Learning System) i.e. capacitor between the voltage and ground connections, resistor in series on the data signal and got nothing.
I then tried seeing if I had perhaps mixed up the pins while soldering and noticed something odd. If I connected the "DOUT" pin to the 5V and left the "VDD" pin unconnected, the LED behaved exactly how I expected (correct colour and delays as per the above code). Setup below (apologies for wires going everywhere):
So I then thought that maybe the "DOUT" and "VDD" pins have been mixed up and that I would just have to wire in accordance to this pinout:
But I did this to no avail. The 2nd LED in series does not respond to any commands issued from the "DOUT" pin (originally VDD) if I assume the above pinout is correct.
I'm at a loss now as to what the problem could be. I have already received my custom PCBs that I was hoping to wire the LEDs onto but if the pinouts aren't matching what I thought they would be the PCBs are more or less useless. As I stated earlier, this is the second order of LEDs that are behaving like this so I'm almost certain it is something I am doing rather than a problem with the datasheet but I can't figure out what.
Please let me know if you think you can help or need anymore information! Thanks 
