File content as of revision 8:45797dcd8b66:

#include "PID.h"

//led controlled
const double Kp =.00001;
const double Ki = 0;
const double Kd = 0.1;
const double decay=1;

double total_error=0;
double prev_error=0;

//error based on encoders
double PID()
{
    double error = 0;
    error= signed( counterM1- counterM2);
    double P = Kp * error;
    total_error = (total_error+error);
    double I = Ki * total_error;
    total_error /= decay;

    double D = Kd * (error - prev_error);
    prev_error = error;
    return P + I+ D;
}

//error for led
const double Kp_e =.00001;
const double Ki_e = 0;
const double Kd_e = 0;
const double decay_e=1;

double total_error_e=0;
double prev_error_e=0;


double PID_e()
{
    double error = 0;
    error= signed ( LL_t.read_u16()-RR_t.read_u16());

    double P = Kp_e * error;
    total_error = (total_error+error);
    double I = Ki_e * total_error;
    total_error /= decay_e;
    double D = Kd_e * (error - prev_error);
    prev_error = error;
    return (P + I+ D);
}

//opening on right side
bool opening_r(double threshold_p, double threshold_d)
{
    return threshold_p < LL_t.read_u16() && prev_error > threshold_d;
}

bool opening_l(double threshold_p, double threshold_d)
{
    return threshold_p < LL_t.read_u16() && prev_error > threshold_d;
}

//wall in fron the car
bool wall_front(double threshold_r, double threshold_l)
{
    return threshold_r < R_t.read_u16() && threshold_l < L_t.read_u16();
}