#include <Adafruit_NeoPixel.h>

#define PIN 2
#define NUM_MATRICES 5
#define LEDS_PER_MATRIX 25
#define NUMPIXELS (NUM_MATRICES * LEDS_PER_MATRIX)
#define BRIGHTNESS 1000

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

// Define the positions of LEDs to form the letters
const int hPattern[] = {0,4,5,9,10,11,12,13,14,15,19,20,24};
const int ePattern[] = {0,1,2,3,4,5,10,11,12,13,14,15,20,21,22,23,24};
const int lPattern[] = {0,5,10,15,20,21,22,23,24};
const int oPattern[] = {0,1,2,3,4,5,9,10,14,15,19,20,21,22,23,24};

void setup() {
  pixels.begin();
  pixels.setBrightness(BRIGHTNESS);
}

void loop() {
  // Display "HELLO" word
  displayWord(hPattern, sizeof(hPattern) / sizeof(hPattern[0]), 0);
  displayWord(ePattern, sizeof(ePattern) / sizeof(ePattern[0]), 1);
  displayWord(lPattern, sizeof(lPattern) / sizeof(lPattern[0]), 2);
  displayWord(lPattern, sizeof(lPattern) / sizeof(lPattern[0]), 3);
  displayWord(oPattern, sizeof(oPattern) / sizeof(oPattern[0]), 4);
  
  delay(500); // Delay to keep the word on for 1000 milliseconds
  pixels.clear(); // Clear all LEDs

  // Shift each letter pattern by one whole matrix
  for (int matrix = 0; matrix < NUM_MATRICES; matrix++) {
    displayWord(hPattern, sizeof(hPattern) / sizeof(hPattern[0]), (matrix + 1) % NUM_MATRICES);
    displayWord(ePattern, sizeof(ePattern) / sizeof(ePattern[0]), (matrix + 2) % NUM_MATRICES);
    displayWord(lPattern, sizeof(lPattern) / sizeof(lPattern[0]), (matrix + 3) % NUM_MATRICES);
    displayWord(lPattern, sizeof(lPattern) / sizeof(lPattern[0]), (matrix + 4) % NUM_MATRICES);
    displayWord(oPattern, sizeof(oPattern) / sizeof(oPattern[0]), (matrix + 5) % NUM_MATRICES);
    
    delay(1000); // Delay between shifting each letter by one whole matrix
    pixels.clear(); // Clear all LEDs
  }
  
  //delay(500); // Delay to keep the LEDs off for 1000 milliseconds
}

// Function to display a letter pattern on the specified matrix
void displayWord(int pattern[], int patternSize, int matrix) {
  for (int i = 0; i < patternSize; i++) {
    int index = matrix * LEDS_PER_MATRIX + pattern[i];
    pixels.setPixelColor(index, pixels.Color(255, 0, 0)); // Red
  }
  pixels.show(); // Show the updated pixels
}