/*detection of ultrasonic distance*/
int watch(){
  long howfar;
  digitalWrite(Trig_PIN,LOW);
  delayMicroseconds(5);                                                                              
  digitalWrite(Trig_PIN,HIGH);
  delayMicroseconds(15);
  digitalWrite(Trig_PIN,LOW);
  howfar=pulseIn(Echo_PIN,HIGH);
  howfar=howfar*0.01657; //how far away is the object in cm
  //Serial.print((int)howfar);
  //Serial.println(" cm");
  return round(howfar);
}
//Meassures distances to the right, left, front, left diagonal, right diagonal and asign them in cm to the variables rightscanval, 
//leftscanval, centerscanval, ldiagonalscanval and rdiagonalscanval (there are 5 points for distance testing)
void watchsurrounding(){                     
  centerscanval = watch();
  if(centerscanval<distancelimit){
    stop_Stop();
    Serial.println("stop");
    alarm();
    }
  head.write(120);
  delay(100);
  ldiagonalscanval = watch();
  if(ldiagonalscanval<distancelimit){
    stop_Stop();
    Serial.println("stop");
    alarm();
    }
  head.write(170); //Didn't use 180 degrees because my servo is not able to take this angle
  delay(300);
  leftscanval = watch();
  if(leftscanval<sidedistancelimit){
    stop_Stop();
    Serial.println("stop");
    alarm();
    }
  head.write(120);
  delay(100);
  ldiagonalscanval = watch();
  if(ldiagonalscanval<distancelimit){
    stop_Stop();
    Serial.println("stop");
    alarm();
    }
  head.write(90); //use 90 degrees if you are moving your servo through the whole 180 degrees
  delay(100);
  centerscanval = watch();
  if(centerscanval<distancelimit){
    stop_Stop();
    Serial.println("stop");
    alarm();
    }
  head.write(40);
  delay(100);
  rdiagonalscanval = watch();
  if(rdiagonalscanval<distancelimit){
    stop_Stop();
    Serial.println("stop");
    alarm();
    }
  head.write(0);
  delay(100);
  rightscanval = watch();
  if(rightscanval<sidedistancelimit){
    stop_Stop();
    Serial.println("stop");
    alarm();
    }
  head.write(90); //Finish looking around (look forward again)
  delay(300);
}

void auto_avoidance(){
  go_Advance();  // if nothing is wrong go forward using go() function above.
  Serial.println("forward");
  set_Motorspeed(AD_SPEED1,AD_SPEED1);
  ++numcycles;
  if(numcycles>100){ //Watch if something is around every 100 loops while moving forward 
    watchsurrounding();
    if(leftscanval<sidedistancelimit || ldiagonalscanval<distancelimit){
      go_Right();
      Serial.println("turn right");
      set_Motorspeed(AD_SPEED1,AD_SPEED1);
      delay(turntime);
    }
    if(rightscanval<sidedistancelimit || rdiagonalscanval<distancelimit){
      go_Left();
      Serial.println("turn left");
      set_Motorspeed(AD_SPEED1,AD_SPEED1);
      delay(turntime);
    }
    if((rightscanval<sidedistancelimit || rdiagonalscanval<distancelimit)\
        &&(leftscanval<sidedistancelimit || ldiagonalscanval<distancelimit)\
        &&(centerscanval<distancelimit)){
          go_Back();
          Serial.println("go back");
          set_Motorspeed(AD_SPEED1,AD_SPEED1);
          delay(2*turntime);
          go_Left();
          set_Motorspeed(AD_SPEED1,AD_SPEED1);
          delay(turntime);
        }
    numcycles=0; //Restart count of cycles
  }
  distance = watch(); // use the watch() function to see if anything is ahead (when the robot is just moving forward and not looking around it will test the distance in front)
  if (distance<distancelimit){ // The robot will just stop if it is completely sure there's an obstacle ahead (must test 25 times) (needed to ignore ultrasonic sensor's false signals)
      ++thereis;}
  if (distance>distancelimit){
      thereis=0;} //Count is restarted
  if (thereis > 25){
    stop_Stop(); // Since something is ahead, stop moving.
    Serial.println("stop");
    thereis=0;
  }
}