#define Laser SENSOR_1
#define Bump SENSOR_3

#define R_Motor OUT_C
#define L_Motor OUT_A
#define Both_Motors OUT_C+OUT_A

#define Right 1
#define Left 0

task main ()
{
  SetSensor (Laser, SENSOR_LIGHT); // Laser sensor is used as a Light sensor
  SetSensorMode (Laser, SENSOR_MODE_BOOL); // Using Boolean mode, returns true when the sensor sees a target.
  SetSensor (Bump, SENSOR_TOUCH);

  OnFwd (L_Motor);
  Off(R_Motor);
  until (Laser);  //turn right actively till we see a target
  while (Laser);  // then turn more to go past target
  SetEvent (1, SENSOR_3, EVENT_TYPE_RELEASED); // set event to monitor bumper

  while (true)
  {
    monitor( EVENT_MASK(1))
    {
      OnFwd (Both_Motors);  // Go forward
      SetPower(L_Motor,0); // slowly drifting left
      until (Laser); // till we see target
      while (Laser); // and go past it
      SetPower(L_Motor,7);  // then turn right actively
      OnFwd (L_Motor);
      Off(R_Motor);
      until (Laser);
      while (Laser);
    }
    catch // we bumped on something (target ?).
    {
      SetPower(Both_Motors,7);
      OnRev (Both_Motors);  // back up a little
      Wait(50);
      Off (L_Motor);  // turn a little
      Wait(20);
      OnFwd (L_Motor); // then look for next target
      Off(R_Motor);
      until (Laser);
      while (Laser);
    }
  }

}