#define THRESH_1       8
#define THRESH_2      23
#define FACTOR_2      31
#define THRESH_4      55
#define FACTOR_4      64
#define THRESH_8     117
#define FACTOR_8     124

int leftOutside, leftInside, rightInside, rightOutside;
int skip;

task main()
{

  SetSensorType(SENSOR_1, SENSOR_TYPE_TOUCH);  //Turn off light power
  SetSensorType(SENSOR_2, SENSOR_TYPE_TOUCH);  //4 bit DtoA converter
  SetSensorMode(SENSOR_2, SENSOR_MODE_RAW);    //Raw mode
  SetSensorType(SENSOR_3, SENSOR_TYPE_TOUCH);  //Turn off light power
  
  while (true)
  {
    Off(OUT_A + OUT_C);               //Stop
    do                                //Wait until feet touch ground
    {
      ReadSensors();
    } until (leftOutside + leftInside + rightOutside + rightInside < 4);
    skip = 0;

    OnRev(OUT_A + OUT_C);             //Reverse to back edge of traverse
    WaitWatching(60);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    OnFwd(OUT_A + OUT_C);             //Forward to front edge of traverse
    WaitWatching(120);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    OnRev(OUT_A + OUT_C);             //Reverse to center of traverse
    WaitWatching(60);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    OnFwd(OUT_A);                     //Turn right in place to face right
    OnRev(OUT_C);
    WaitWatching(100);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    OnFwd(OUT_A + OUT_C);             //Forward to right edge of traverse
    WaitWatching(60);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    OnRev(OUT_A + OUT_C);             //Reverse to left edge of traverse
    WaitWatching(120);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    OnFwd(OUT_A + OUT_C);             //Forward to center of traverse
    WaitWatching(60);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    OnRev(OUT_A);                     //Turn left in place to face forward
    OnFwd(OUT_C);
    WaitWatching(100);
    if (skip != 0) continue;

    Off(OUT_A + OUT_C);               //Stop
    WaitWatching(5);
    if (skip != 0) continue;

    break;                            //Quit
  }
}

void WaitWatching(int time)    //Wait time 10ths of a second
{    
  ClearTimer(0);
  while (Timer(0) < time)
  {
    continue;                  //Ignore the sensors for now

    ReadSensors();
    if (leftOutside + leftInside + rightOutside + rightInside > 3)
    {
      skip = 1;
      break;
    }
  }
}

int sensor, level;

sub ReadSensors()
{
  sensor = SENSOR_2;
  level = sensor * 32 / (1024 - sensor);
  if (level < THRESH_8) rightOutside = 0; else
  {
    rightOutside = 1;
    level = level - FACTOR_8;
  }
  if (level < THRESH_4) rightInside = 0; else
  {
    rightInside = 1;
    level = level - FACTOR_4;
  }
  if (level < THRESH_2) leftInside = 0; else
  {
    leftInside = 1;
    level = level - FACTOR_2;
  }
  if (level < THRESH_1) leftOutside = 0; else leftOutside = 1;
}