File content as of revision 3:01b5e80d842d:

class Wheel 
{
    private:
    
    float distance; //distance traversed by wheel
    float angularVelocity;
    
        float const static gain = 1.2f; //closed loop gain, (amount to amplify the difference) you have to tune this value
    //but make sure its less than 1.5 otherwise you'll have a really sensitive motor
    
    PwmOut Mtr; //connect this pin to the motor driveboard pwm
    DigitalOut direction; //connected to the direction pin of motor drive board
    DigitalOut polarity; //connected to the bipolar of motor drive board. 0 = unipolar 1 = bipolar
    
    Ticker updater;

    Encoder* enc;
    
    P controller;
    
    public:
    
    float  maxAngularVel;
    
    float static const wheelDiameter = 0.18; //used in calculation of Linear velocity i.e never
    
    Wheel (Encoder* E, PinName M, PinName D, PinName Mode) : Mtr(M), direction(D), polarity(Mode), controller(gain)
        {
        maxAngularVel = 0.0f;
        enc = E;
        polarity = 0;   
        direction = 0;
        distance = 0;
        Mtr.period_us(100); //frequency of 5KHz determine this constant value based on switching losses+frequency losses
        //higher freq -> more switching losses lower freq -> more "capacitive losses" need to find a balance
        Mtr.write(1); //start off on the turned off state
        
        updater.detach();
        
        controller.setOutputLimits(-1.0f, 1.0f);
        }
    
    void calculateAngularVelocity() //returns a float value which is the angular velocity of the WHEEL
    {
        float eTR = enc->encoderTickRate();
        angularVelocity = (eTR/256.0f)*2.0f*(float)PI;
    }
    
    void setFrequency(int freq) //if you want to adjust the frequency
    {
        Mtr.period(1/freq);
    }
    
    float returnAngularVelocity() //as it says
    {
        return angularVelocity;
    }
    
    //only called once during initialization to calculate max angular velocity 
    //dir = direction, do opposite for each wheel just so your buggy doesn't move FORWARD but rather rotates
    void init(int dir) 
    {
      enc->startTimer();
      Mtr.write(0); //max speed
      angularVelocity = 10.0f;
      direction = dir;
      updater.detach();
      updater.attach(callback(this, &Wheel::init2),2.0f); //used as a wait preferably put this wait just long enough that the buggy will do a full 360 degree turn so that it hasn't moved
    }
    
    void init2(void) //used as a temporarily wait command for the wheel to spin to max
    {
        calculateAngularVelocity();
        maxAngularVel = abs(angularVelocity);
        controller.setInputLimits(-1.0f*abs(angularVelocity),abs(angularVelocity));
        controller.setControl(0.0f);
        updater.detach();
        updater.attach(callback(this, &Wheel::wheelUpdates),0.2f);  //attached the actual update function from now ON    
    }
    
    void wheelUpdates(void) //sampling rate the ticker is attached I.E the wheel speed is updated everytiem this function is called
        {
            calculateAngularVelocity();
            float temp2 = controller.compute(angularVelocity); //another temporary value to store the computed angular velocity
            if (temp2 < 0) {direction = 1;} else {direction = 0;} //change direction according to the computed value
            temp2 = abs(temp2);
            Mtr.write(1.0f - temp2); //write the value as a pwm
        }
        
    void adjustAngularVelocity(float W) // W = angular velocity you want, obviously putting a |w| value that is > max angular velocity will set dutcy cycle to max
        {
        controller.setControl(W);
        if (W < 0.0f) {direction = 1;} else {direction = 0;} //obvs if you put a negative value -> will get a negative direction i.e 0;
        };
        
    float getDistance(void)
    {
    return distance; //distance traversed by wheel
    }
    
    float returnMaxAngularVel(void)
    {
        return  maxAngularVel;
    }
    
    
};