Colony » Colony Scout » Colony Scout OS

#ifndef _LINE_FOLLOW_H_

#define _LINE_FOLLOW_H_

#include "../Behavior.h"

#define LWHITE                        0

#define LGREY                        1

#define LBLACK                         2

#define BAD_READING     3

#define CENTER                        3

#define LINELOST                -1

#define INTERSECTION         -25

#define NOLINE                        -50

#define FULL_LINE                 -51

#define NUM_READINGS 20

#define LEFT_SENSOR     1

#define RIGHT_SENSOR    0

/**

 * Helps with debugging.

 * 0 - no debug output.

 * 1 - print out buckets

 * 2 - print out line sensor readings

 */

#define DBG_LINEFOLLOW 2

//! A simple function to return the minimum of two integers.

int min(int x, int y);

//! A simple function to return the maximum of two integers.

int max(int x, int y);

class line_follow 

{

        public:

    /** Actually executes the behavior. */

                void init();

    /**        line_follow

     *        Must call line_follow_init first

     *        Must be called inside a loop

     */

    int follow_line(int speed);

    /**        turnLeft turnRight

     *        Must be called inside a loop

     *        returns 0 when complete

     */

    int turnLeft(void);

    int turnRight(void);

    /**

     * @brief Updates the values stored in the array to white or black based on

     * current sensor readings.

     *

     * @param values The array of five integers to be updated. 

     */

    void updateLine(int* values); 

    /**

     * @brief Returns an index of the middle of the line based on line readings.

     *

     * Two special return values are possible:

     *   NOLINE if none of the sensors holds a black value, and

     *   FULL_LINE if all of the sensors see black.

     *

     * Otherwise, returns a value from -4 (farthest left) to 4 (farthest right), with

     * 0 the line being centered in the middle.

     *

     * @param colors The array of 5 readings from the line sensor.  Must be either

     *    LWHITE or LBLACK.

     * @return Either a special value or an index from -4 to 4.

     *

     */

    int lineLocate(int* colors);

    /** @todo Alex: I hate these functions, but I'm keeping them so code will still work. But we should delete them sometime. */

    /**        motorLeft

     *        Commands the left motor

     *        Cannot be used to stop

     *        0-126 are backward

     *        127-255 are forward

     */

    void motorLeft(int speed);

    /**        motorRight

     *        Commands the right motor

     *        Cannot be used to stop

     *        0-126 are backward

     *        127-255 are forward

     */

    void motorRight(int speed);

    private:

    /**        lost

     *        Internal counter to detect if the line was lost

     */

    int lost;

};

#endif