void disp2(int num)
{
  if(num == 0)//0000
  {
    digitalWrite(b1, LOW);//
    digitalWrite(b2, LOW);//0
    digitalWrite(b3, LOW);//0
    digitalWrite(b4, LOW);//0
  }
  if(num == 1)//0001
  {
    digitalWrite(b1, HIGH);//1
    digitalWrite(b2, LOW);//0
    digitalWrite(b3, LOW);//0
    digitalWrite(b4, LOW);//0
  }
  if(num == 2)//0010
  {
    digitalWrite(b1, LOW);//0
    digitalWrite(b2, HIGH);//1
    digitalWrite(b3, LOW);//0
    digitalWrite(b4, LOW);//0
  }
  if(num == 3)//0011
  {
    digitalWrite(b1, HIGH);//1
    digitalWrite(b2, HIGH);//1
    digitalWrite(b3, LOW);//0
    digitalWrite(b4, LOW);//0
  }
  if(num == 4)//0100
  {
    digitalWrite(b1, LOW);//0
    digitalWrite(b2, LOW);//0
    digitalWrite(b3, HIGH);//1
    digitalWrite(b4, LOW);//0
  }
  if(num == 5) //0101
  {
    digitalWrite(b1, HIGH);//1
    digitalWrite(b2, LOW);//0
    digitalWrite(b3, HIGH);//1
    digitalWrite(b4, LOW);//0
  }
  if(num == 6) //0110
  {
    digitalWrite(b1, LOW);//0
    digitalWrite(b2, HIGH);//1
    digitalWrite(b3, HIGH);//1
    digitalWrite(b4, LOW);//0
  }
  if(num == 7) //0111
  {
    digitalWrite(b1, HIGH);//1
    digitalWrite(b2, HIGH);//1
    digitalWrite(b3, HIGH);//1
    digitalWrite(b4, LOW);//0
  }
  if(num == 8) //1000
  {
    digitalWrite(b1, LOW);//0
    digitalWrite(b2, LOW);//0
    digitalWrite(b3, LOW);//0
    digitalWrite(b4, HIGH);//1
  }
  if(num == 9)//1001
  {
    digitalWrite(b1, HIGH);//1
    digitalWrite(b2, LOW);//0
    digitalWrite(b3, LOW);//0
    digitalWrite(b4, HIGH);//1
  }
}