 
 void setup() {
   // put your setup code here, to run once:
-
   motors.configure();
   sensors.configure();
   Serial.begin(9600);
-
+  
 }
 
 void loop() {
   // put your main code here, to run repeatedly:
-
+    phone();
     sensors.updateError();
     calculate_pid();
     motors.drive(PID_value);

    
    previous_error=error;
    
    Serial.print("pidval : ");
      Serial.print(PID_value);
    Serial.println("\t");
/**
    Serial.print("P : ");
    Serial.print(P);
    Serial.print("\t");


void calculate_pid()
{
    error = (sensors.error)*10;
    P = error;
    I = I + error;
    D = error - previous_error;
