NeoPixel Strip with Ghosting/Random led lighting up

Projects Programming
1

I have a strange problem with a very small WS8212 led strip (a so called 8-bit strip, with 8 leds on a pcb).
It seems to display random colors/pixels when trying to set a pixel. I've added a small 470 ohm R in the data line and the power is sufficient with also ground connected to the Wemos D1 mini ground.

A small code part show below. First I turn off all the pixels and the set a new one to a certain color. Sometimes this causes other pixels on the strip randomly turn on as well, different color and brightens, and no pattern at all..

colorWipe(strip.Color(0,0,0),10); //All off 
setLedPixelColor(3, strip.Color(128,128,0)); 

void colorWipe(uint32_t c, uint8_t wait) {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    setLedPixelColor(i, c);
    delay(wait);
  }
}

void setLedPixelColor(int pixel, uint32_t color) {
  strip.setPixelColor(pixel, color);
  strip.show();
}

Any ideas?

2

with also ground connected to the Wemos D1 mini ground.

thats the two power supply grounds, right? Double check they are really well connected

Another known issue with 3.3v logic and 5v power is described there

3

Another known issue with 3.3v logic and 5v power

Most likely the issue, i use a simple 7400 series TTL chip to up the logic level to 5v. Those consider anything over 2v to be logic HIGH and put out 5v if powered by 5v