int pin[7] = {23,22, 21, 18,5,4,2};   //   Seven segment pin is connected to Digital pin 15,2,4,5,18,19,21 to a,b,c,d,e,f,g

const byte count[10] = {  // this is data code for Seven segment 
  //GFEDCBA
  B1000000,  //0
  B1111001, // 1
  B0100100, // 2
  B0110000, //3
  B0011001, //4
  B0010010, //5
  B0000010, //6
  B1111000, //7
  B0000000, //8
  B0010000 //9
};
void setup() {
  pinMode(pin[0], OUTPUT);  // every pin is output
  pinMode(pin[1], OUTPUT);
  pinMode(pin[2], OUTPUT);
  pinMode(pin[3], OUTPUT);
  pinMode(pin[4], OUTPUT);
  pinMode(pin[5], OUTPUT);
  pinMode(pin[6], OUTPUT);
}
void loop() {
  for(int i = 0; i<10; i++){ // printing the number on seven segment
    SevenSeg(count[i]);
    delay(1000);
  }
}
void SevenSeg(byte Bit) { //  sending data on each pin
  for(int i=0; i<7; i++)
  digitalWrite(pin[i],bitRead(Bit,i));
}