// steerbot1_hassoun.nqc
//   a simple bumper car with rack & pinion steering
//   no events are used

#define CENTER   SENSOR_1
#define EYE      SENSOR_2

#define STEER    OUT_A
#define DRIVE    OUT_C

#define FULL_TURN_TIME   50
#define STRAIGHT_TIME    50


void right()
{
    Fwd(STEER);
    OnFor(STEER, FULL_TURN_TIME);
}


void left()
{
    Rev(STEER);
    OnFor(STEER, FULL_TURN_TIME);
}


void center()
{
    Toggle(STEER);
    On(STEER);
    until(CENTER==1);
    Off(STEER);
}

task send_signal()
{
  while(true)
    {
    SendMessage(85);  //use 85 or 255 value for more IR activity!!
    Wait(10);
    }
}

task main()
{
     int lastlevel;
     
    // set up sensors and event
    SetSensor(CENTER, SENSOR_TOUCH);
    SetSensorType(EYE, SENSOR_TYPE_LIGHT);
    SetSensorMode(EYE, SENSOR_MODE_RAW);

    // align wheels and drive forward
    left();
    center();
    On(DRIVE);
    
    // use high power communication
    SetTxPower(TX_POWER_HI);
    start send_signal;
    
    while(true)
    {
     lastlevel = EYE;
     if(EYE < lastlevel - 100)
        {
            // back up while turning
            Rev(DRIVE);
            right();        
            Wait(STRAIGHT_TIME);  // effect?
            
            // forward while turning other direction
            Fwd(DRIVE);
            left();
            
            // center steer
            center();
        }
    }
}