/*
  ESP32 / 7 segment count up demo
  Green wires are segments, grey wires are digits.
  In a real circuit NPN drivers should be used for each digit.
  Beerware - 9/1/25
*/

const int DP_POS = 2; // decimal point at 3rd digit
// Define digit control pins (D1 to D4)
const int DIGIT_PINS[4] = {16, 17, 5, 18};
// Define segment pins (A-G, DP)
const int SEG_PINS[8] = {13, 33, 26, 14, 12, 32, 25, 27};
// Segment configuration for numbers 0-9 (A to G, DP)
const byte DIGITS[][8] = {
  {1, 1, 1, 1, 1, 1, 0, 0}, // 0
  {0, 1, 1, 0, 0, 0, 0, 0}, // 1
  {1, 1, 0, 1, 1, 0, 1, 0}, // 2
  {1, 1, 1, 1, 0, 0, 1, 0}, // 3
  {0, 1, 1, 0, 0, 1, 1, 0}, // 4
  {1, 0, 1, 1, 0, 1, 1, 0}, // 5
  {1, 0, 1, 1, 1, 1, 1, 0}, // 6
  {1, 1, 1, 0, 0, 0, 0, 0}, // 7
  {1, 1, 1, 1, 1, 1, 1, 0}, // 8
  {1, 1, 1, 1, 0, 1, 1, 0}, // 9
  {0, 0, 0, 0, 0, 0, 0, 0}  // blank
};

// show a number on a specific digit
void showDigit(int num, int digit) {
  for (int i = 0; i < 8; i++) {
    if (digit == DP_POS && i == 7)  {
      digitalWrite(SEG_PINS[i], 1);
    } else {
      digitalWrite(SEG_PINS[i], DIGITS[num][i]);
    }
  }
  // toggle digit pin
  digitalWrite(DIGIT_PINS[digit], LOW);  // enable digit
  digitalWrite(DIGIT_PINS[digit], HIGH); // disable digit
}

// display a 4-digit number on the 7-segment display
void showNumber(int number) {
  int digitArray[4];
  for (int i = 3; i >= 0; i--) {
    digitArray[i] = number % 10;
    number /= 10;
  }
  for (int i = 0; i < 4; i++) {
    showDigit(digitArray[i], i);
  }
}

/*
// display a 4-digit number on the 7-segment display
void showNumber(int number) {
  int digitArray[4] = {
    number / 1000,
    (number / 100) % 10,
    (number / 10) % 10,
    number % 10
  };
  for (int i = 0; i < 4; i++) {
    showDigit(digitArray[i], i);
  }
}
*/

void setup() {
  Serial.begin(115200);
  for (int i = 0; i < 8; i++) {
    pinMode(SEG_PINS[i], OUTPUT);
  }
  for (int i = 0; i < 4; i++) {
    pinMode(DIGIT_PINS[i], OUTPUT);
  }
  Serial.println("Ready");
}

void loop() {
  for (int i = 0; i < 10000; i++) {
    showNumber(i);
    delay(100);
  }
}