Arduino “having11” Guy
Published © GPL3+

Building a Large NeoPixel Matrix

Construct a 20 x 15 LED matrix to display cool graphics and text while allowing for future upgrades.

BeginnerFull instructions provided3 hours3,238

Things used in this project

Hardware components

LED Strip, 5 m
LED Strip, 5 m
Total of 300 LEDs
×2
5V 5A Power Supply
×1

Software apps and online services

Arduino IDE
Arduino IDE
VS Code
Microsoft VS Code

Hand tools and fabrication machines

Soldering iron (generic)
Soldering iron (generic)

Story

Read more

Schematics

Schemtaic

Code

NeoPixel Code

C/C++
//Adafruit's RGBW test code

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

#define LED_PIN     3

#define LED_COUNT  300

#define BRIGHTNESS 50

Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, NEO_GRBW + NEO_KHZ800);

void setup() {
  
  strip.begin();           
  strip.show();            
  strip.setBrightness(50); 
}

void loop() {
  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);

  whiteOverRainbow(75, 5);

  pulseWhite(5);

  rainbowFade2White(3, 3, 1);
}


void colorWipe(uint32_t color, int wait) {
  for(int i=0; i<strip.numPixels(); i++) { 
    strip.setPixelColor(i, color);         
    strip.show();                          
    delay(wait);                           
  }
}

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(;;) { 
    for(int i=0; i<strip.numPixels(); i++) {  
      if(((i >= tail) && (i <= head)) ||      
         ((tail > head) && ((i >= tail) || (i <= head)))) {
        strip.setPixelColor(i, strip.Color(0, 0, 0, 255)); 
      } else {                                            
        int pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());
        strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue)));
      }
    }

    strip.show(); 
    
    firstPixelHue += 40; 

    if((millis() - lastTime) > whiteSpeed) { 
      if(++head >= strip.numPixels()) {      
        head = 0;
        if(++loopNum >= loops) return;
      }
      if(++tail >= strip.numPixels()) {      
        tail = 0;
      }
      lastTime = millis();                   
    }
  }
}

void pulseWhite(uint8_t wait) {
  for(int j=0; j<256; 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;

  for(uint32_t firstPixelHue = 0; firstPixelHue < rainbowLoops*65536;
    firstPixelHue += 256) {

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

      uint32_t pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());

      strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue, 255,
        255 * fadeVal / fadeMax)));
    }

    strip.show();
    delay(wait);

    if(firstPixelHue < 65536) {                              
      if(fadeVal < fadeMax) fadeVal++;                       
    } else if(firstPixelHue >= ((rainbowLoops-1) * 65536)) { 
      if(fadeVal > 0) fadeVal--;                             
    } else {
      fadeVal = fadeMax; 
    }
  }

  for(int k=0; k<whiteLoops; k++) {
    for(int j=0; j<256; j++) { 
      strip.fill(strip.Color(0, 0, 0, strip.gamma8(j)));
      strip.show();
    }
    delay(1000); 
    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); 
}

Credits

Arduino “having11” Guy

Arduino “having11” Guy

81 projects • 538 followers
18 year-old IoT and embedded systems enthusiast. Also an intern at Hackster.io who loves working on projects and sharing knowledge.

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