#define A 2
#define B 3
#define C 4
#define D 5
#define E 6
#define FF 7
#define G 8

// Pins driving common anodes
#define CC1 9
#define CC2 10
#define CC3 11
// Pins for A B C D E F G, in sequence
const int segs[7] = { 2, 3, 4, 5, 6, 7, 8 };

// Segments that make each number
const byte numbers[10] = { 0b0111111, 0b0000110, 0b1011011, 0b1001111, 0b1100110, 0b1101101, 0b1111101, 0b0000111, 0b1111111, 0b1101111};

int digit1 = 0;
int digit2 = 0;
int digit3 = 0;
int digit4 = 0;
int val;
int val2;

void setup()
{
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
  pinMode(E, OUTPUT);
  pinMode(FF, OUTPUT);
  pinMode(G, OUTPUT);
  pinMode(CC1, OUTPUT);
  pinMode(CC2, OUTPUT);
  pinMode(CC3, OUTPUT);
  Serial.begin(9600);
}

void loop()
{
  int valorADC;
  float voltaje;
  valorADC = analogRead(A0);
  voltaje = valorADC * (5.0 / 1023.0);
  int voltage=(int)voltaje*10;
  int num0,num1,num2,num3;

  num0=voltage;

  num1=num0%10;      // Extract the value of unit digit
  num0=num0-num1;
  num0=num0/10;

  num2=num0%10;     // Extract the value of decade digit
  num0=num0-num2;
  num0=num0/10;

  num3=num0%10;     // Extract the value of hundred digit
  num0=num0-num3;
  num0=num0/10;
  //Serial.println(voltaje);
  //delay(2);

  lightDigit1(numbers[num1]);
  delay(2);
  lightDigit2(numbers[num2]);
  delay(2);
  lightDigit3(numbers[num3]);
  delay(2);
}
  void lightDigit1(byte number)
  {
    digitalWrite(CC1, LOW);
    digitalWrite(CC2, HIGH);
    digitalWrite(CC3, HIGH);
    lightSegments(number);
  }

  void lightDigit2(byte number)
  {
    digitalWrite(CC1, HIGH);
    digitalWrite(CC2, LOW);
    digitalWrite(CC3, HIGH);
    lightSegments(number);
  }

  void lightDigit3(byte number)
  {
    digitalWrite(CC1, HIGH);
    digitalWrite(CC2, HIGH);
    digitalWrite(CC3, LOW);
    lightSegments(number);
  }

  void lightSegments(byte number)
  {
    for (int i = 0; i < 7; i++)
    {
      int bit = bitRead(number, i);
      digitalWrite(segs[i], bit);
    }
  }