// Pins connected to the A-G segments of the 7-segment display
const int segmentPins[] = {D2, D3, D4, D5, D6, D7, D8};

// Turn-on patterns for digits 0 to 9 (common anode display)
// Bit order: G F E D C B A
// 0 = ON (LOW), 1 = OFF (HIGH)
const byte digitPatterns[10] = {
  0b1000000, // 0
  0b1111001, // 1
  0b0100100, // 2
  0b0110000, // 3
  0b0011001, // 4
  0b0010010, // 5
  0b0000010, // 6
  0b1111000, // 7
  0b0000000, // 8
  0b0010000  // 9
};

// Custom sequence of numbers to display
int numberSequence[] = {8, 1, 1, 4, 1, 4, 5, 1, 8};

// Total number of digits in the sequence
int sequenceLength = 9;

// Current index within the sequence
int sequenceIndex = 0;

void setup() {
  Serial.begin(115200);

  // Configures each display pin as an output and turns it off (HIGH in common anode)
  for (int i = 0; i < 7; i++) {
    pinMode(segmentPins[i], OUTPUT);
    digitalWrite(segmentPins[i], HIGH);
  }

  Serial.println("7 SEGMENT DISPLAY - CLEAN AND COMMENTED");
  Serial.println("Sequence: 8, 1, 1, 4, 1, 4, 5, 1, 8");
}

// Function that displays a number from 0 to 9 on the display
void displayDigit(int value) {
  
  // If the value is out of range, everything is turned off
  if (value < 0 || value > 9) {
    for (int i = 0; i < 7; i++) {
      digitalWrite(segmentPins[i], HIGH);
    }
    return;
  }

  // The binary pattern corresponding to the number is obtained
  byte pattern = digitPatterns[value];

  // The pattern is written to the display pins
  // (In common anode: HIGH = off, LOW = on)
  for (int i = 0; i < 7; i++) {
    // Check if the i-th bit is 1 (Turn OFF) or 0 (Turn ON)
    if ((pattern >> i) & 1) {
      digitalWrite(segmentPins[i], HIGH); // Turn segment OFF
    } else {
      digitalWrite(segmentPins[i], LOW);  // Turn segment ON
    }
  }
}

void loop() {
  // Gets the current number from the sequence
  int currentNumber = numberSequence[sequenceIndex];

  // Displays it on the display
  displayDigit(currentNumber);

  // Prints the current state to the serial monitor
  Serial.print("Number [");
  Serial.print(sequenceIndex + 1);
  Serial.print("/");
  Serial.print(sequenceLength);
  Serial.print("]: ");
  Serial.println(currentNumber);

  // Moves to the next number in the sequence
  sequenceIndex++;

  // If it reaches the end, it restarts
  if (sequenceIndex >= sequenceLength) {
    sequenceIndex = 0;
    Serial.println("Restarting sequence");
  }

  // Waits 1 second before showing the next one
  delay(1000);
}