File content as of revision 1:eace997e9a93:

/*

Sensor measurement header file. 
Contains the pin declarations and variables for all sensors-related work
Also contains the measurement function - should it???


TODO 
-decide whether pins should be Interrupts INs or is it going to be polling - polling atm
- how to distingisuh between different sensor on/off frequency - maybe create a new class??
- 

NEED TESTING!
LAST REVISED 13/02
*/

#ifndef _SENSOR_MEASURE_H
#define _SENSOR_MEASURE_H

#define NUMBER_SAMPLES 40 // NUMBER OF SAMPLES FOR SENSOR TESTING

//define pinout for all the sensors
DigitalIn pin_right_right(PTD0);
InterruptIn pin_right_centre(PTD1);
InterruptIn pin_right_left(PTD2);
InterruptIn pin_left_right(PTD3);
InterruptIn pin_left_centre(PTD4);
InterruptIn pin_left_left(PTD5);
//InterruptIn in(PTD0); maybe more~?

//timer used by the sensor
Timer sensorTimer;

//structure for sensors
typedef struct sensor_data {
    DigitalIn* pin; //TODO can;t seem to be able to declara this
    int  black_value;
    int  white_value;    
}sensor_data;

/*
All sensors should be declared in the MAIN PROGRAM????
sensor_data right_right;
sensor_data.pin = &pin_right_right;
right_right.black_value = 2013;
sensor_data.white_value = 10000;
*/
sensor_data right_right;
sensor_data right_centre;
// and so on....

//Initialise values of all sensors
void sensor_initialise () {
    //right_right
    right_right.pin = &pin_right_right;
    right_right.black_value = 2013;
    right_right.white_value = 10000;
    //and contiune so on..
}


//measuring function - returning whether it is black or white line 
//"1" - black, "0" - white
int measure (sensor_data sensor){


    
    sensorTimer.reset();
    int freq,period = 0;
    int n =0; //number of samples
    int sensor_old  = 0;//variable to remember old sensor state
    
    while (n < NUMBER_SAMPLES){
        
        if (*sensor.pin == 1 && sensor_old == 0){ // detect on rising edge
            n++;
        }
        sensor_old = *sensor.pin;
    }
    
    period = sensorTimer.read_us()/(float)n; // Get time
    freq = (1/period)*1000000;   // Convert period (in us) to frequency (Hz). Works up to 100kHz. 
    
    
    return (freq < sensor.black_value*2)? 1 : 0;
}
#endif