Jelenleg ez van:

int a=2;
int b=3;
int c=4;
int d=5;
int e=6;
int f=7;
int g=8;
int D1=13;
int D2=9;
int D3=10;
int D4=A5;
int num =0;
int x=0;
int y=0;
int z=0;
int w=0;
int speed =3000;
unsigned long previousMillis = 0;
//                          a,b,c,d,e,f,g
int num_array[10][7] = {  { 1,1,1,1,1,1,0 },    // 0
                          { 0,1,1,0,0,0,0 },    // 1
                          { 1,1,0,1,1,0,1 },    // 2
                          { 1,1,1,1,0,0,1 },    // 3
                          { 0,1,1,0,0,1,1 },    // 4
                          { 1,0,1,1,0,1,1 },    // 5
                          { 1,0,1,1,1,1,1 },    // 6
                          { 1,1,1,0,0,0,0 },    // 7
                          { 1,1,1,1,1,1,1 },    // 8
                          { 1,1,1,1,0,1,1 }};   // 9
                                       
//function header
void Num_Write(int);



void setup()
{
  Serial.begin(9600);
  pinMode(D1,OUTPUT);
  pinMode(D2,OUTPUT);
  pinMode(D3,OUTPUT);
  pinMode(D4,OUTPUT);
  pinMode(2, OUTPUT);   
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  //pinMode (A5,OUTPUT);
  //pinMode(12,INPUT_PULLUP);

 
}

void loop()
{
 unsigned long currentMillis = millis();
//speed= analogRead(A4);
//speed = map(speed, 0, 1023, 10, 1000);
x = num ;
y = num/10;
z= num/100;
w= num/1000;
Serial.print(speed);
 while (currentMillis - previousMillis < speed)
 {     
  currentMillis = millis();
  Num_Write(x);
  digitalWrite(D1,LOW);
  digitalWrite(D2,HIGH);
  digitalWrite(D3,HIGH);
delay(8);  
  Num_Write(y);
  digitalWrite(D1,HIGH);
  digitalWrite(D2,LOW);
  digitalWrite(D3,HIGH);
delay(8);
  Num_Write(z);
  digitalWrite(D1,HIGH);
  digitalWrite(D2,HIGH);
  digitalWrite(D3,LOW);
delay(8);   
//Num_Write(w);
  //digitalWrite(D1,HIGH);
  //digitalWrite(D2,HIGH);
  //digitalWrite(D3,LOW);
//delay(8);   
 }
  if (currentMillis - previousMillis >= speed)
      previousMillis = currentMillis;
 Serial.print ("X= ");
 Serial.println (x);
  Serial.print ("Y= ");
  Serial.println (y);
  Serial.print ("Z= ");
  Serial.println (z);
   Serial.print ("Speed= ");
  Serial.println (speed);
  if(digitalRead(A0))
  {
    num--;
  if(num ==10000)
    num=0;
  }
  else
  {
    num++;
  if(num <0)
    num=999;
  }
}

// this functions writes values to the sev seg pins  
void Num_Write(int number)
{
  int pin= 2;
  for (int j=0; j < 7; j++) {
   digitalWrite(pin, num_array[number][j]);
   pin++;
  }
}