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

 const byte digits [10][7] = {
 {1 ,1 ,1 ,1 ,1 ,1 ,0} , 
 {0 ,1 ,1 ,0 ,0 ,0 ,0} , 
 {1 ,1 ,0 ,1 ,1 ,0 ,1} , 
 {1 ,1 ,1 ,1 ,0 ,0 ,1} , 
 {0 ,1 ,1 ,0 ,0 ,1 ,1} , 
 {1 ,0 ,1 ,1 ,0 ,1 ,1} , 
 {1 ,0 ,1 ,1 ,1 ,1 ,1} , 
 {1 ,1 ,1 ,0 ,0 ,0 ,0} , 
 {1 ,1 ,1 ,1 ,1 ,1 ,1} , 
 {1 ,1 ,1 ,1 ,0 ,1 ,1} 
};

 const byte pinCode [4] = {3 , 1 , 4 , 2};


 void setup () {
 for (int i = 0; i < 7; i ++) {
 pinMode ( segmentPins [ i ] , OUTPUT ) ;
    }
 for (int i = 0; i < 4; i ++) {
 pinMode ( digitPins [ i ] , OUTPUT ) ;
  }
}

 void loop () {
 for (int i = 0; i < 4; i ++) {
 
 for (int d = 0; d < 4; d ++) {
 digitalWrite ( digitPins [ d ] , HIGH ) ;
    }

 for (int s = 0; s < 7; s ++) {
 digitalWrite ( segmentPins [ s ] , digits [ pinCode [ i ]][ s ]) ;
    }

 digitalWrite ( digitPins [ i ] , LOW ) ;

 delay (5) ; 
    }
 }