File content as of revision 0:9c49bdc7e402:

#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 for sharp turns or forward movement
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;
}

//encoder controlled
const double Kp_e =1;
const double Ki_e = 0;
const double Kd_e = 0.1;
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;
    }