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16x16 LED (255 LEDs) only lights 65 LEDs
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16x16 LED (255 LEDs) only lights 65 LEDs

by Kenan1313 on Wed Dec 26, 2018 5:31 am

Hello Support Team,

I have searched the forums, but do not seem to find a similar issue to the one I have.
Namely, the Arduino only lights the first 65 LEDs out of 255.
In the picture below I ran the "simple" example code of the Adafruit NeoPixel Library.
https://www.dropbox.com/s/os0w4pess6f2lzz/20181226_100148.jpg?dl=0

Code: Select all | TOGGLE FULL SIZE
// NeoPixel Ring simple sketch (c) 2013 Shae Erisson
// released under the GPLv3 license to match the rest of the AdaFruit NeoPixel library

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif

// On a Trinket or Gemma we suggest changing this to 1
#define PIN            13

// How many NeoPixels are attached to the Arduino?
#define NUMPIXELS      255

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_RBG + NEO_KHZ800);

int delayval = 100; // delay for half a second

void setup() {
  // This is for Trinket 5V 16MHz, you can remove these three lines if you are not using a Trinket
#if defined (__AVR_ATtiny85__)
  if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
#endif
  // End of trinket special code

  pixels.begin(); // This initializes the NeoPixel library.
}

void loop() {

  // For a set of NeoPixels the first NeoPixel is 0, second is 1, all the way up to the count of pixels minus one.

  for(int i=0;i<NUMPIXELS;i++){

    // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
    pixels.setPixelColor(i, pixels.Color(0,50,0)); // Moderately bright green color.

    pixels.show(); // This sends the updated pixel color to the hardware.

    delay(delayval); // Delay for a period of time (in milliseconds).

  }
}


I know for sure that the issue lies behind GND. Because if I play with the 5V Output, meaning I put in and put out the wire fastly, the whole boards flickers. This means that all LEDs get enough power. But If I do the same with GND than only LEDS till 65 flicker.

What does this mean? Is there a possibility that I made something wrong or is the Neopixel defect?

I would truly appreciate the help since it's for my bachelor thesis.

Best regards
Kanan
Last edited by Kenan1313 on Sun Jan 06, 2019 9:00 am, edited 1 time in total.

Kenan1313
 
Posts: 4
Joined: Wed Dec 26, 2018 4:48 am

Re: 16x16 LED (255 LEDs) only lights 65 LEDs

by AevaLighting on Fri Dec 28, 2018 12:39 am

The middle led is broken?

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Posts: 5
Joined: Fri Dec 28, 2018 12:27 am

Re: 16x16 LED (255 LEDs) only lights 65 LEDs

by Kenan1313 on Wed Jan 02, 2019 8:58 am

Hello,
sorry for the late response. The LEDs are not broken. The current from GRND flows only til the 65th LED of the 255 LEDs. This way only the first 65 LEDs light up

Kenan1313
 
Posts: 4
Joined: Wed Dec 26, 2018 4:48 am

Re: 16x16 LED (255 LEDs) only lights 65 LEDs

by adafruit_support_carter on Thu Jan 03, 2019 1:33 pm

Inlining image for reference:
20181226_100148_scaled.jpg
20181226_100148_scaled.jpg (274.26 KiB) Viewed 74 times

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Re: 16x16 LED (255 LEDs) only lights 65 LEDs

by adafruit_support_carter on Thu Jan 03, 2019 1:34 pm

Can you please clarify which display you have - PID number or just link to product page would help. Also, can you post another photo showing the back side of the display.

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Re: 16x16 LED (255 LEDs) only lights 65 LEDs

by Kenan1313 on Sat Jan 05, 2019 4:30 am

Hello,

The product ID of the LED matrix is 812B1LED1616, from ALITOVE. The matrix is actually a strip of 256 single WS2812B components.

The backside can be seen here https://www.dropbox.com/s/e4yquuo4er0t43v/20190104_131325.jpg?dl=0

Best regards,
Kanan

Kenan1313
 
Posts: 4
Joined: Wed Dec 26, 2018 4:48 am

Re: 16x16 LED (255 LEDs) only lights 65 LEDs

by Kenan1313 on Sun Jan 06, 2019 9:02 am

Noticed just now that the link was false...
Anyway, corrected it

Kenan1313
 
Posts: 4
Joined: Wed Dec 26, 2018 4:48 am

Re: 16x16 LED (255 LEDs) only lights 65 LEDs

by adafruit_support_carter on Mon Jan 07, 2019 1:36 pm

We don't know anything about that display. It might not work with our driver.

20190104_131325_scaled.jpg
20190104_131325_scaled.jpg (381.64 KiB) Viewed 42 times

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Please be positive and constructive with your questions and comments.