int pot = A0;
int seg1 = 2;
int seg2 = 3;
int seg3 = 5;
int seg4 = 6;
int seg5 = 9;
int seg6 = 10;
int seg7 = 11;
int val = 0;

void setup() {
  pinMode(pot, INPUT);
  pinMode(seg1, OUTPUT);
  pinMode(seg2, OUTPUT);
  pinMode(seg3, OUTPUT);
  pinMode(seg4, OUTPUT);
  pinMode(seg5, OUTPUT);
  pinMode(seg6, OUTPUT);
  pinMode(seg7, OUTPUT);
}

void loop() {
  val = readPot(pot);
  setDisplay(val);
}

void setDisplay (int number){
  switch (number) {
    case 1:
      digitalWrite(seg1, HIGH);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, HIGH);
      digitalWrite(seg5, HIGH);
      digitalWrite(seg6, HIGH);
      digitalWrite(seg7, HIGH);
      break;
    
    case 2:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, HIGH);
      digitalWrite(seg4, LOW);
      digitalWrite(seg5, LOW);
      digitalWrite(seg6, HIGH);
      digitalWrite(seg7, LOW);
      break;
    
    case 3:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, LOW);
      digitalWrite(seg5, HIGH);
      digitalWrite(seg6, HIGH);
      digitalWrite(seg7, LOW);
      break;
    
    case 4:
      digitalWrite(seg1, HIGH);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, HIGH);
      digitalWrite(seg5, HIGH);
      digitalWrite(seg6, LOW);
      digitalWrite(seg7, LOW);
      break;
    
    case 5:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, HIGH);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, LOW);
      digitalWrite(seg5, HIGH);
      digitalWrite(seg6, LOW);
      digitalWrite(seg7, LOW);
      break;
    
    case 6:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, HIGH);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, LOW);
      digitalWrite(seg5, LOW);
      digitalWrite(seg6, LOW);
      digitalWrite(seg7, LOW);
      break;
    
    case 7:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, HIGH);
      digitalWrite(seg5, HIGH);
      digitalWrite(seg6, HIGH);
      digitalWrite(seg7, HIGH);
      break;
    
    case 8:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, LOW);
      digitalWrite(seg5, LOW);
      digitalWrite(seg6, LOW);
      digitalWrite(seg7, LOW);
      break;
    
    case 9:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, LOW);
      digitalWrite(seg5, HIGH);
      digitalWrite(seg6, LOW);
      digitalWrite(seg7, LOW);
      break;
    
    default:
      digitalWrite(seg1, LOW);
      digitalWrite(seg2, LOW);
      digitalWrite(seg3, LOW);
      digitalWrite(seg4, LOW);
      digitalWrite(seg5, LOW);
      digitalWrite(seg6, LOW);
      digitalWrite(seg7, HIGH);
  }
}

int readPot(int pin) {
  return map(analogRead(pin), 0, 1023, 0, 9);
}