File content as of revision 3:717de74f6ebd:

// Eurobot13 Colour.h


#include "mbed.h"
#include "Led.h"
#include "Phototransistor.h"

enum ColourEnum {BLUE, RED, WHITE, INCONCLUSIVE, BUG};

class Colour{
private:
    Led blue;   float bavg, bstdev;
    Led red;    float ravg, rstdev; 
    Phototransistor pt;
    
public:
    Colour(PinName bluePin, PinName redPin, PinName phototransistorPin)
        : blue(bluePin)
        , red (redPin)
        , pt (phototransistorPin)
        {
        LedsOff();
    }

    void Calibrate(){
        ReadLed(blue, bavg, bstdev);
        ReadLed( red, ravg, rstdev);
    }
        
    ColourEnum getColour(){
        bool blueb = isColour(blue, bavg, bstdev)
            , redb = isColour( red, ravg, rstdev);
                  
        if      ( blueb &&  redb)
                    {return WHITE;}
        else if ( blueb && !redb)
                    {return BLUE;}
        else if (!blueb &&  redb)
                    {return RED;}
        else if (!blueb && !redb)
                    {return INCONCLUSIVE;} 
        return BUG;            
    }

private:
    void LedsOff(){blue.off(); red.off();}
    void ReadLed (Led &led, float &avg, float &stdev, const int measureNum = 25){
        LedsOff(); led.on();
        double x = 0, x2 = 0;
        for (int i = measureNum; i != 0; i--){
            float v = pt.read();
            x += v;
            x2+= v*v;
        }
        avg = x / measureNum;
        stdev = sqrt(x2 / measureNum - avg*avg);
        LedsOff();
        
        pc.printf("Phototransistor Analog is: %f\t%f\n\r", avg, stdev);
    }
    
    bool isColour(Led &led, const float &avg, const float &stdev, const float numstddev = 2 ){
        float avg2, stdev2;
        ReadLed(led, avg2, stdev2);
        
        if (avg + numstddev*stdev < avg2 - numstddev*stdev2){
            return true;
        } else {
            return false;
        }
    }
    


};