Colony

 /**

 * @file rangefinder_with_noise.c

 * @author Colony Project

 *

 * @brief Returns rangefinder units with noise given distance in cm.

 *

 * Adds a random, normal amount of noise to a rangefinder

 * value given in cm. Returns approximate IR units .

 **/

double get_rangefinder(double dist_in_cm)

{

        double cm, IR, noise;

        // gauss_init(1, 0); // Params are chaos scalar and seed

        // noise = gauss_noise(void); // Gives ther noise

        cm = dist_in_cm; // Enter value between 7 and 18 for accurate results

        IR = 15.4005 * cm; // 15.4005 is an experimental value

        /*  Rangefinder is good for values between 7 and 18.

        *        3 < cm < 7 AND 18 < cm < 22 are significantly more erroneous.

        *        cm < 3 and cm > 22, rangefinder reports -1

        */

        if ( cm < 3 || cm > 22 )

        {

                return -1;

        }

        else if( cm < 7 || cm > 18 )

        {

                gauss_init(2, 0);

                noise = gauss_noise();

                return IR + noise;

        }

        else 

        {

                gauss_init(1, 0);

                noise = gauss_noise();

                return IR + noise;

        }

}