File content as of revision 8:aff2a7d5861a:

#include "mbed.h"
#include "MODSERIAL.h"
#include "encoder.h"
// this program can turn the motor clockwise or counterclockwise depending on the value p or n typed into the terminal. with 's' you can stop the motor

MODSERIAL pc(USBTX,USBRX);
PwmOut motorspeed(D6);
PwmOut motorspeed2(D5);
DigitalOut motorposition2(D4);
DigitalOut motorposition(D7);
DigitalOut led1(D8);
DigitalOut led2(D11);
AnalogIn pot(A1);
AnalogIn pot2(A2);
DigitalIn button1(D13);
DigitalIn button2(D12);
Ticker potmeterreadout;
Ticker encoderreadout;
Encoder motor1(PTD0,PTC4); // motor 1 is from encoder, otherwise it would be a pain in the ass to change all that code to motorencoder


float PwmPeriod = 0.0001f;

const double M1_TS = 0.01f;                                                             // timestep
const double M1_KP = 0.216, M1_KI = 1.8, M1_KD = 0.0;                                     // controller gains for motor 1
double m1_err_int = 0, m1_prev_err = 0;                                                 // initiallize errors

// PID controller function
double PI(double e, const double Kp, const double Ki, const double Kd, double Ts, double&e_int){
  //double e_der = (e - e_prev)/Ts;       // derivative
  //e_der = biquad(e_der, f_v1, f_v2, f_a1, f_a2, f_b0, f_b1, f_b2);
  //e_prev = e;
  e_int = e_int + Ts*e;                 // integral   
  return Kp*e + Ki*e_int;    //PI controller
  }


volatile float position = 0.0;
void readpot(){
    position = motor1.getPosition()/4200.00*6.28;
    float motorpi = PI(reference - position, M1_KP, M1_KI, M1_KD, M1_TS, m1_err_int);
    pc.printf("PI output = %f, reference = %i\n\r", motorpi, reference);
    //motorspeed = motorpi;
    }


int main()
{  
    float reference = 0.0;
    pc.baud(9600);
    potmeterreadout.attach(readpot,0.2f);
    motorspeed2.period(PwmPeriod);
    //float motorspeed = 0.0f;
    while (true) {
        reference = 0.0;
        wait(2.0f);
        reference = 1.0;
        wait(5.0f);
       
    }
}