Only the very first LED turns on when code inputed and wired

I am just starting a project and also first time with LED's. I am using the WS2812B (these), however when I wire it up to the Arduino (ELEGOO Uno R3) and external power source (this) It only seems to light up the very first LED.

For the code I used the Adafruit neopixel strip test and also the code from fast FASTLED.

I have made sure that I am using the correct end of the LED strips with the arrows facing away, I have made sure that there is a ground between the strip the external power, and the Arduino. Using a multi meter I also tested the strip and between every led all the way down is getting power.

Thanks in advance, any help would be appreciated.

This is currently how it is wired (I tried with and without the resistor)

Of course the issue could be in the code but without properly formatted code in code tags, the world may never know.

// NeoPixel test program showing use of the WHITE channel for RGBW
// pixels only (won't look correct on regular RGB NeoPixel strips).

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
 #include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif

// Which pin on the Arduino is connected to the NeoPixels?
// On a Trinket or Gemma we suggest changing this to 1:
#define LED_PIN     6

// How many NeoPixels are attached to the Arduino?
#define LED_COUNT  150

// NeoPixel brightness, 0 (min) to 255 (max)
#define BRIGHTNESS 50 // Set BRIGHTNESS to about 1/5 (max = 255)

// Declare our NeoPixel strip object:
Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, NEO_GRBW + NEO_KHZ800);
// Argument 1 = Number of pixels in NeoPixel strip
// Argument 2 = Arduino pin number (most are valid)
// Argument 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)
//   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products)

void setup() {
  // These lines are specifically to support the Adafruit Trinket 5V 16 MHz.
  // Any other board, you can remove this part (but no harm leaving it):
#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000)
  clock_prescale_set(clock_div_1);
#endif
  // END of Trinket-specific code.

  strip.begin();           // INITIALIZE NeoPixel strip object (REQUIRED)
  strip.show();            // Turn OFF all pixels ASAP
  strip.setBrightness(BRIGHTNESS);
}

void loop() {
  // Fill along the length of the strip in various colors...
  colorWipe(strip.Color(255,   0,   0)     , 50); // Red
  colorWipe(strip.Color(  0, 255,   0)     , 50); // Green
  colorWipe(strip.Color(  0,   0, 255)     , 50); // Blue
  colorWipe(strip.Color(  0,   0,   0, 255), 50); // True white (not RGB white)

  whiteOverRainbow(75, 5);

  pulseWhite(5);

  rainbowFade2White(3, 3, 1);
}

// Fill strip pixels one after another with a color. Strip is NOT cleared
// first; anything there will be covered pixel by pixel. Pass in color
// (as a single 'packed' 32-bit value, which you can get by calling
// strip.Color(red, green, blue) as shown in the loop() function above),
// and a delay time (in milliseconds) between pixels.
void colorWipe(uint32_t color, int wait) {
  for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...
    strip.setPixelColor(i, color);         //  Set pixel's color (in RAM)
    strip.show();                          //  Update strip to match
    delay(wait);                           //  Pause for a moment
  }
}

void whiteOverRainbow(int whiteSpeed, int whiteLength) {

  if(whiteLength >= strip.numPixels()) whiteLength = strip.numPixels() - 1;

  int      head          = whiteLength - 1;
  int      tail          = 0;
  int      loops         = 3;
  int      loopNum       = 0;
  uint32_t lastTime      = millis();
  uint32_t firstPixelHue = 0;

  for(;;) { // Repeat forever (or until a 'break' or 'return')
    for(int i=0; i<strip.numPixels(); i++) {  // For each pixel in strip...
      if(((i >= tail) && (i <= head)) ||      //  If between head & tail...
         ((tail > head) && ((i >= tail) || (i <= head)))) {
        strip.setPixelColor(i, strip.Color(0, 0, 0, 255)); // Set white
      } else {                                             // else set rainbow
        int pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());
        strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue)));
      }
    }

    strip.show(); // Update strip with new contents
    // There's no delay here, it just runs full-tilt until the timer and
    // counter combination below runs out.

    firstPixelHue += 40; // Advance just a little along the color wheel

    if((millis() - lastTime) > whiteSpeed) { // Time to update head/tail?
      if(++head >= strip.numPixels()) {      // Advance head, wrap around
        head = 0;
        if(++loopNum >= loops) return;
      }
      if(++tail >= strip.numPixels()) {      // Advance tail, wrap around
        tail = 0;
      }
      lastTime = millis();                   // Save time of last movement
    }
  }
}

void pulseWhite(uint8_t wait) {
  for(int j=0; j<256; j++) { // Ramp up from 0 to 255
    // Fill entire strip with white at gamma-corrected brightness level 'j':
    strip.fill(strip.Color(0, 0, 0, strip.gamma8(j)));
    strip.show();
    delay(wait);
  }

  for(int j=255; j>=0; j--) { // Ramp down from 255 to 0
    strip.fill(strip.Color(0, 0, 0, strip.gamma8(j)));
    strip.show();
    delay(wait);
  }
}

void rainbowFade2White(int wait, int rainbowLoops, int whiteLoops) {
  int fadeVal=0, fadeMax=100;

  // Hue of first pixel runs 'rainbowLoops' complete loops through the color
  // wheel. Color wheel has a range of 65536 but it's OK if we roll over, so
  // just count from 0 to rainbowLoops*65536, using steps of 256 so we
  // advance around the wheel at a decent clip.
  for(uint32_t firstPixelHue = 0; firstPixelHue < rainbowLoops*65536;
    firstPixelHue += 256) {

    for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...

      // Offset pixel hue by an amount to make one full revolution of the
      // color wheel (range of 65536) along the length of the strip
      // (strip.numPixels() steps):
      uint32_t pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());

      // strip.ColorHSV() can take 1 or 3 arguments: a hue (0 to 65535) or
      // optionally add saturation and value (brightness) (each 0 to 255).
      // Here we're using just the three-argument variant, though the
      // second value (saturation) is a constant 255.
      strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue, 255,
        255 * fadeVal / fadeMax)));
    }

    strip.show();
    delay(wait);

    if(firstPixelHue < 65536) {                              // First loop,
      if(fadeVal < fadeMax) fadeVal++;                       // fade in
    } else if(firstPixelHue >= ((rainbowLoops-1) * 65536)) { // Last loop,
      if(fadeVal > 0) fadeVal--;                             // fade out
    } else {
      fadeVal = fadeMax; // Interim loop, make sure fade is at max
    }
  }

  for(int k=0; k<whiteLoops; k++) {
    for(int j=0; j<256; j++) { // Ramp up 0 to 255
      // Fill entire strip with white at gamma-corrected brightness level 'j':
      strip.fill(strip.Color(0, 0, 0, strip.gamma8(j)));
      strip.show();
    }
    delay(1000); // Pause 1 second
    for(int j=255; j>=0; j--) { // Ramp down 255 to 0
      strip.fill(strip.Color(0, 0, 0, strip.gamma8(j)));
      strip.show();
    }
  }

  delay(500); // Pause 1/2 second
}

Sorry completely forgot to add

That diagram looks very odd to me!

Check that you are connecting the wires to the correct pads on the strip; ground, data in and 5 V.

This is the usual arrangement, but different strips may vary.

If you look at the link to the lights i sent they don't actually need to be soldered, they have a plug at the end that I am using, My setup is what you sent minus the capacitor.

To clear the LEDs I use this function

void clearLEDs()
{
  for (int i = 0; i < LED_COUNT; i++)
  {
    leds.setPixelColor(i, 0);
  }
} // void clearLEDs()

In setup(), I do the following:

leds.begin(); // Call this to start up the LED strip.
  clearLEDs();  // This function, defined below, de-energizes all LEDs...
  leds.show();  // ...but the LEDs don't actually update until you call this.

I set LED colors to all the LEDs to be ignited and then I call show:

for (;;)
  {
    if (xQueueReceive( xQ_LED_Info, &iFreqVal,  portMAX_DELAY) == pdTRUE)
    {
      j = 0;
      //assign different values for different parts of the led strip
      for (j = 0; j < LED_COUNT; j++)
      {
        if ( (0 <= j) && (j < (LED_COUNT / SEG)) )
        {
          set(j, iFreqVal[0]); // set the color of led
        }
        else if ( ((LED_COUNT / SEG) <= j) && (j < (LED_COUNT / SEG * 2)) )
        {
          set(j, iFreqVal[1]); //orginal code
        }
        else if ( ((LED_COUNT / SEG * 2) <= j) && (j < (LED_COUNT / SEG * 3)) )
        {
          set(j, iFreqVal[2]);
        }
        else if ( ((LED_COUNT / SEG * 3) <= j) && (j < (LED_COUNT / SEG * 4)) )
        {
          set(j, iFreqVal[3]);
        }
        else if ( ((LED_COUNT / SEG * 4) <= j) && (j < (LED_COUNT / SEG * 5)) )
        {
          set(j, iFreqVal[4]);
        }
        else
        {
          set(j, iFreqVal[5]);
        }
      }
      leds.show();
    }

Thanks I'll give that a go.

The set() function

void set(byte position, int value)
{
  // segment 0, red
  if ( (0 <= position) && (position < LED_COUNT / SEG) ) // segment 0 (bottom to top), red
  {
    if ( value == 0 )
    {
      leds.setPixelColor( position, 0, 0, 0 );
    } else {
      // increase light output of a low number
      // value += 10;
      // value = constrain( value, 0, 255 ); // keep raised value within limits
      if ( value <= 25 )
      {
        leds.setPixelColor( position, leds.Color( value , 0, 0) );
      } else {
        if ( (value * LED0_Multiplier) >= 255 )
        {
          leds.setPixelColor( position, leds.Color( 255 , 0, 0) );
        } else {
          leds.setPixelColor( position, leds.Color( (value * LED0_Multiplier) , 0, 0) );
        }
      }
    }
  }
  else if ( (LED_COUNT / SEG <= position) && (position < LED_COUNT / SEG * 2) ) // segment 1 yellow
  {
    if ( value == 0 )
    {
      leds.setPixelColor(position, leds.Color(0, 0, 0));
    }
    else
    {
      leds.setPixelColor(position, leds.Color( value, value, 0)); // works better to make yellow
    }
  }
  else if ( (LED_COUNT / SEG * 2 <= position) && (position < LED_COUNT / SEG * 3) ) // segment 2 pink
  {
    if ( value == 0 )
    {
      leds.setPixelColor(position, leds.Color(0, 0, 0));
    }
    else
    {
      leds.setPixelColor(position, leds.Color( value, 0, value * .91) ); // pink
    }
  }
  else if ( (LED_COUNT / SEG * 3 <= position) && (position < LED_COUNT / SEG * 4) ) // seg 3, green
  {
    if ( value == 0 )
    {
      leds.setPixelColor(position, leds.Color( 0, 0, 0));
    }
    else //
    {
      leds.setPixelColor( position, leds.Color( 0, value, 0) ); //
    }
  }
  else if ( (LED_COUNT / SEG * 4 <= position) && (position < LED_COUNT / SEG * 5) ) // segment 4, leds.color( R, G, B ), blue
  {
    if ( value == 0 )
    {
      leds.setPixelColor(position, leds.Color( 0, 0, 0));
    }
    else //
    {
      leds.setPixelColor(position, leds.Color( 0, 0, value) ); // blue
    }
  }
  else // segment 5
  {
    if ( value == 0 )
    {
      leds.setPixelColor(position, leds.Color( 0, 0, 0)); // only helps a little bit in turning the leds off
    }
    else
    {
      leds.setPixelColor( position, leds.Color( value, value * .3, 0) ); // orange
    }
  }
} // void set(byte position, int value)

Unfortunately nothing has seemed to work, I have tried other code. Still only the first LED turns on, I also tried cutting just in case the power draw was to high for my external power.

Now I am only trying to power 13 LEDs and it just does the first one

Figured it out, the second LED data connection was faulty so I just have to cut out second LED and works fine.

Thanks for the help.

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.