#include     int data[3], v[2]; int i=0, j=0, n=0, prov=320, num, plus=320, plus1=240, aum=45, aum1=45; char c; Servo servo1; Servo servo2;   void setup() {   servo1.attach(2);   servo2.attach(3);     Serial.begin(9600); }   void loop() {     //Read Serial bus data received from Python and write them into servo position   if(Serial.available())   {     prov=Serial.read()-48;     if(prov!=72)     {       data[i]=prov;       i++;     }     else     {       if(i==0)         num=0;       if(i==1)         num=data[0];       if(i==2)         num=data[1]+data[0]*10;       if(i==3)         num=data[2]+data[1]*10+data[0]*100;       i=0;       v[n]=num;       n++;       if(n==2)       {         //Start X axis         while(plus>0)         {           if((v[0]<=plus) && (v[0]>(plus-10)))           {             servo1.write(aum-5);             delay(15);             plus=0;           }           else           {             plus=plus-10;             aum=aum+3;           }         }         plus=320;         aum=45;         //Start Y axis         while(plus1>0)         {           if((v[1]<=plus1) && (v[1]>(plus1-10)))           {             servo2.write(aum1);             delay(15);             plus1=0;           }           else           {             plus1=plus1-10;             aum1=aum1+3;           }         }         plus1=240;         aum1=45;         n=0;       }     }   } }