File content as of revision 1:4bd14d5374c3:

//////////////////////////////////////
// basen on PwmIn Library
// Basis is to disable the interrupts
// of the other PwmIn inputs
///////////////////////////////////////
#include "mbed.h"
#include "InterruptIn.h"
#define NR 20

class PwmIn
{
public:
    PwmIn(PinName p);
    float period();
    float pulsewidth();
    float dutycycle();
    void disable();  

protected:
    void rise();
    void fall();

    InterruptIn _p;
    Timer _t;
    volatile float _pulsewidth, _period;
};

PwmIn::PwmIn(PinName p) : _p(p)
{
    _p.rise(this, &PwmIn::rise);
    _p.fall(this, &PwmIn::fall);
    _period = 0.0;
    _pulsewidth = 0.0;
    _t.start();
}

PwmIn a(PTD2);  // Sensor 1 X direction
PwmIn b(PTA17); // Sensor 1 Y direction
Serial pc(USBTX, USBRX); // tx, rx

float PwmIn::period()
{
    return _period;
}

float PwmIn::pulsewidth()
{
    return _pulsewidth;
}

float PwmIn::dutycycle()
{
    return _pulsewidth / _period;
}

void PwmIn::disable()
{
   // _p.enable_irq();
}

void PwmIn::rise()
{
    _period = _t.read();
    _t.reset();
}

void PwmIn::fall()
{
    _pulsewidth = _t.read();
}

struct product {
    float pulse;
    float width;
    float duty;
} acc_a[NR], acc_b[NR], acc_c[NR],acc_d[NR];


int main()
{
    char pbuffer[60]="---";
    int i;

    while(1) {
     //   a.disable();                            // Stop interrupts for sensor B
        for (i=0; i<NR; i++) {
            acc_a[i].duty= a.dutycycle();       // Sensor A
            acc_b[i].duty= b.dutycycle();
        }

        for (i=0; i<NR; i++) {
            sprintf(pbuffer, " a= %f, b= %f \n\r", acc_a[i].duty, acc_b[i].duty);
            pc.puts(pbuffer);
        }
    }
}