File content as of revision 1:813f4b17ae65:

class Wheel 
{
    private:
    
    float distance; //distance traversed by wheel
    float angularVelocity;
    
        float const static gain = 0.6f; //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(0.6f)
        {
        enc = E;
        polarity = 0;   
        direction = 0;
        distance = 0;
        
        Mtr.period_us(200); //frequency of 1KHz 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
        updater.detach();
        
        controller.setControl(10.0f);
        controller.setOutputLimits(-1.0f, 1.0f);
        }
    
    float calculateAngularVelocity() //returns a float value which is the angular velocity of the WHEEL
    {
        float eTR;
        eTR = enc->encoderTickRate();
        angularVelocity = (eTR/256.0f)*2.0f*(float)PI;
        return eTR;
    }
    
    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) 
    {
      Mtr.write(0); //max speed
      direction = dir;
      updater.attach(callback(this, &Wheel::init2),1); //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
    {
        float temp = enc->encoderTickRate();
        angularVelocity = (temp/256.0f)*2.0f*(float)PI;
        maxAngularVel = angularVelocity;
        controller.setInputLimits(-1.0f*angularVelocity,angularVelocity);
        updater.attach(callback(this, &Wheel::wheelUpdates),0.1);  //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
        {
            if (angularVelocity >= (controller.returnControl()+1.0f) || angularVelocity <= (controller.returnControl()-1.0f)) //only compute if their is a difference between wanted and current val
            {
            float temp = enc->encoderTickRate(); //get the encoder tick rate and store in a value called temp
            angularVelocity = (temp/256.0f)*2.0f*(float)PI; //use it to calculate the angular velocity of the wheel
            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
            Mtr.write(temp2); //write the value as a pwm
            distance += angularVelocity * wheelDiameter;
            }
        }
    void adjustAngularVelocity(float W) // W = angular velocity you want, obviously putting a |w| value that is > max angular velocity will set dutcy cycle to 1
        {
        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
    }
    
};