Square 8x8 Addressable LED Display

#include <Adafruit_NeoPixel.h>

#define DATA_PIN   14
#define NUM_LEDS   64
#define BRIGHTNESS 30

Adafruit_NeoPixel strip(NUM_LEDS, 14, NEO_GRB + NEO_KHZ800);

// Serpentine XY mapping for 8x8 grid
uint8_t XY(uint8_t x, uint8_t y) {
  if (y & 1) return y * 8 + (7 - x);
  return y * 8 + x;
}

void setup() {
  Serial.begin(115200);
  Serial.println("8x8 Display Demo Starting...");

  strip.begin();
  strip.setBrightness(BRIGHTNESS);
  strip.clear();
  strip.show();
}

void loop() {
  // Pattern 1: Color wipe
  colorWipe(strip.Color(255, 0, 0), 50);   // Red
  colorWipe(strip.Color(0, 255, 0), 50);   // Green
  colorWipe(strip.Color(0, 0, 255), 50);   // Blue
  
  // Pattern 2: Rainbow cycle
  rainbowCycle(3);
  
  // Pattern 3: Bouncing pixel
  bouncingPixel(80);
}

// Fill display one pixel at a time
void colorWipe(uint32_t color, int wait) {
  for(int y = 0; y < 8; y++) {
    for(int x = 0; x < 8; x++) {
      strip.setPixelColor(XY(x, y), color);
      strip.show();
      delay(wait);
    }
  }
}

// Rainbow effect that cycles through all pixels
void rainbowCycle(int cycles) {
  for(int cycle = 0; cycle < cycles; cycle++) {
    for(int j = 0; j < 256; j++) {
      for(int y = 0; y < 8; y++) {
        for(int x = 0; x < 8; x++) {
          int pixelHue = ((y * 8 + x) * 65536L / NUM_LEDS + j * 256) % 65536;
          strip.setPixelColor(XY(x, y), strip.gamma32(strip.ColorHSV(pixelHue)));
        }
      }
      strip.show();
      delay(20);
    }
  }
}

// Single pixel bouncing around
void bouncingPixel(int frames) {
  int x = 0, y = 0;
  int dx = 1, dy = 1;
  
  for(int i = 0; i < frames; i++) {
    strip.clear();
    
    // Draw trail (fading previous position)
    for(int ty = 0; ty < 8; ty++) {
      for(int tx = 0; tx < 8; tx++) {
        uint32_t c = strip.getPixelColor(XY(tx, ty));
        if(c != 0) {
          // Fade out
          uint8_t r = (c >> 16) & 0xFF;
          uint8_t g = (c >> 8) & 0xFF;
          uint8_t b = c & 0xFF;
          strip.setPixelColor(XY(tx, ty), strip.Color(r/2, g/2, b/2));
        }
      }
    }
    
    // Draw bouncing pixel
    strip.setPixelColor(XY(x, y), strip.Color(255, 255, 255));
    strip.show();
    
    // Update position
    x += dx;
    y += dy;
    
    // Bounce off edges
    if(x <= 0 || x >= 7) dx = -dx;
    if(y <= 0 || y >= 7) dy = -dy;
    
    // Keep in bounds
    x = constrain(x, 0, 7);
    y = constrain(y, 0, 7);
    
    delay(50);
  }
}