---

const int segPins[] = {6, 7, 8, 9, 10, 11, 12, 13};
const int digitPins[] = {5, 4, 3, 2};
const int potPin = A0;

const byte charMasks[] = {
  0b11111100,
  0b01100000,
  0b11011010,
  0b11110010,
  0b01100110,
  0b10110110,
  0b10111110,
  0b11100000,
  0b11111110,
  0b11110110,
  0b11101110,
  0b00111110,
  0b10011100,
  0b01111010,
  0b10011110,
  0b10001110,
  0b11110110,
  0b00101110,
  0b00001100,
  0b01111000,
  0b10001110,
  0b00011100,
  0b11101100,
  0b00101010,
  0b11111100,
  0b11001110,
  0b11100110,
  0b00001010,
  0b10110110,
  0b00011110,
  0b01111100,
  0b01111100,
  0b01111100,
  0b01101110,
  0b01110110,
  0b11011010
};

const int totalChars = sizeof(charMasks);

void setup() {
  for (int i = 0; i < 8; i++) {
    pinMode(segPins[i], OUTPUT);
  }
  
  for (int i = 0; i < 4; i++) {
    pinMode(digitPins[i], OUTPUT);
    digitalWrite(digitPins[i], HIGH);
  }
}

void loop() {
  for (int c = 0; c < totalChars; c++) {
    for (int i = 3; i >= 0; i--) {
      for (int d = 0; d < 4; d++) {
        digitalWrite(digitPins[d], HIGH);
      }
      
      digitalWrite(digitPins[i], LOW);
      
      for (int s = 0; s < 8; s++) {
        bool bitVal = bitRead(charMasks[c], 7 - s);
        digitalWrite(segPins[s], bitVal);
      }
      
      int potValue = analogRead(potPin);
      int delayTime = map(potValue, 0, 1023, 100, 3000);
      delay(delayTime);
    }
  }
}