File content as of revision 0:9f0027e4c618:

#include "mbed.h"
#include "LocalFileSystem.h"
#include "Barometer.h"
#include "math.h"

Serial pc(USBTX, USBRX);
Barometer barometer(p9, p10);
Serial AHRS(p13, p14);

LocalFileSystem local("local");
int i=0;
float p = 0.0f, t = 0.0f, alt = 0.0f;
float roll,pitch,yaw,accx,accy,accz;

int file_no=0;
char filename[256];

int main() {
    AHRS.baud(9600);
    sprintf(filename, "/local/out%d.txt", file_no);    // Open "tem%d.txt" on the local file system for writing
    FILE *fp;
    fp = fopen(filename, "r");
    while(fp){ ////File!!!
        fclose(fp);
        file_no ++;
        sprintf(filename, "/local/out%d.txt", file_no);    // Open "tem%d.txt" on the local file system for writing
        fp = fopen(filename, "r");
        pc.printf("File Yes !! \r\n");
    }
    fp = fopen(filename, "w");    
    for(i=0;i<=50;i++) {
        while(AHRS.getc() != '\n')
        AHRS.scanf("*%f,%f,%f,%f,%f,%f\n", &roll, &pitch, &yaw, &accx,&accy,&accz);
        fprintf(fp, "roll:%f yaw:%f\r\n",roll, yaw);
        pc.printf("%.2f,%.2f,%.2f,%f,%f,%f \r\n", roll, pitch, yaw,accx,accy, accz);
    }
    fclose(fp);
}