File content as of revision 2:a17f7da1ca7c:

#include "mbed.h"
#include <iostream>
#define TI  .001f       //1kHz sample time
#define KP  5.1491f     //Proportional Gain
#define KI  119.3089f   //Integral Gain
#define FPWM .00004f    //PWM Frequency

//Pins
DigitalOut myRled(LED1);
DigitalOut myBled(LED2);
AnalogIn _Reference(PTB0);
AnalogIn _Tacho(PTB2);
PwmOut _MotorControl(PTB1);

Ticker Update;

//Integral Value 
float _errorArea;
float _error;
float _controllerOutput;
float _ref;

//Methods
void Init();
void Loop();
void UpdateMethod();
void UpdateControllerOutput();
void SetMotor(float);

int main() {
    Init();
    while(1) {Loop();}
}

void Init() //Initializer
{
    _MotorControl.period(FPWM);
    SetMotor(0.0f); //Turns off the motor
    _error = 0.0f;
    _errorArea = 0.0f;
    _ref = 0.0f;
    Update.attach(&UpdateMethod, TI);
    //SetMotor(_ref);
}

void Loop() //Repeated Loop
{
    
    wait(5);
    cout<< _ref << endl;
    
}

void UpdateMethod() //
{
    UpdateControllerOutput();
} 
    
void UpdateControllerOutput()
{
    _ref = _Reference.read();
    _error = _ref - _Tacho.read();
    _errorArea += TI*_error;
    _controllerOutput = KP*_error+ KI*_errorArea;
    SetMotor(_controllerOutput);
}

void SetMotor(float speed)
{
    float invD = 0.0f;
    if(speed<0.0f)
    invD =0.0f;
    else if(speed> .75f)
    invD = .75f;
    else
    invD = speed;   
 
    _MotorControl.write(/*1.0f-*/invD);
}