int U,P,I,D;
#define KI 1
#define KD 1
#define KP 1
task p()
{while(true){
  P=(45-Sensor(IN_3));
}            }
task i()
{while(true){
  Wait(10);
  if(abs(45-Sensor(IN_3))<2)
   {I=((45-Sensor(IN_3))+I);}
  else
   {I=0;}
}            }
task d()
{while(true){
  D=((45-Sensor(IN_3))-D);
  Wait(8);
}            }
task calc()
{while(true){
  if (KP*P+KI*I+KD*D<30)
   U=KP*P+KI*I+KD*D;
  else
   U=30;
}            }

task turn()
{ while(true){
  OnFwd(OUT_A, 40 +U);
  OnFwd(OUT_C, 40 -U);
}             }

task main()
{SetSensorLight(IN_3);
Precedes(p,i,d,calc,turn);
I=0;
D=0;}