File content as of revision 0:57a88d862c8b:

#include "mbed.h"
#define buffsize 1500
Serial pc(USBTX, USBRX); // tx, rx

InterruptIn event(p16);
AnalogOut speed(p18);
Timer timer;
PwmOut pwm1(p23);

int start=0;
int stop=0;
int tim=0;
int i=0;
int s=0;
int send=0;

/*
int bufferstart[buffsize];
int bufferstop[buffsize];
*/

void trigger1(void)
{
    if (s==0)
    {
        timer.reset();
        s=1;
    }
    if (send==0)
    {
        start=timer.read_us();
        send=1;
    }
}

void trigger2(void)
{
    if (send==1)
    {
    stop=timer.read_us();
    pc.printf("%i %i ", start, stop);
    send=0;
    }
}

int main() 
{
    pc.baud(921600);
    pwm1.period_us(20); //p=1/f
    pwm1.pulsewidth_us(10); //
    event.rise(&trigger1);
    event.fall(&trigger2);
    timer.start();

    //pc.printf("Init_time %i\n", init_t);
    
    while(1)
    {
    /*    if (i>=(2*buffsize-2))
        {
            __disable_irq();
            int k=0;
            while (k<buffsize-1)
            {
                pc.printf("%i %i ", bufferstart[k], bufferstop[k]);
                k++;
            }
            while(k<=(2*buffsize)-2)
            {
                pc.printf("%i %i ", bufferstart2[k-buffsize-1], bufferstop2[k-buffsize-1]);
                k++;
            }
            while (k>=(2*buffsize)-2)
            {
                
            }
            
        }
        */
    }
}

/*
void trigger1(void)
{
    if (s==0)
    {
        timer.reset();
        s=1;
    }
    if (i<buffsize-1)
    {
    bufferstart[i] = timer.read_us();
    }
    if (i>=buffsize-1)
    {
    bufferstart2[i-buffsize-1] = timer.read_us();
    }
}

void trigger2(void)
{
    if (i<buffsize-1)
    {
    bufferstop[i] = timer.read_us();
    }
    if (i>=buffsize-1)
    {
    bufferstop2[i-buffsize-1] = timer.read_us();
    }
    i++;
}
*/