Not Quite C

// LineFollow.nqc - a simple line following program
// by David Baum

// This program will cause the robot to follow the
// left edge of a black line on a white surface.

// A light sensor should be connected to sensor 2.
// The sensor should be calibrated so that it returns
// a value of around 40-45 on the white surface, and
// a value of 60-65 on the black line.

task main()
{
  SetSensor(SENSOR_2, SENSOR_LIGHT);

  // this is the 'black' threshold
  int threshold = 55;

  while(true)
  {
    if (SENSOR_2 < threshold)
    {
      // on white, turn left
      OnFwd(OUT_C);
      OnRev(OUT_A);
    }
    else
    {
      // on black, turn right
      OnFwd(OUT_A);
      OnRev(OUT_C);
    }
  }
}