File content as of revision 5:a85aa204463b:

/* Program demonstrating data logging to SD card Analog data is read in (from a potentiometer). The time since program start and the voltage are written to a tab-delimited data file.
*/
#include "mbed.h"
#include "SDFileSystem.h"
#include "SDSaveFunction.h"

//Create an SDFileSystem object

SDFileSystem fs(PTD2, PTD3, PTD1, , "fs");
FILE *fp;

extern Serial pc;

int mountSDCard() {
    //Mount the filesystem
    int mountFailure = fs.mount();
    if (mountFailure != 0) {
        pc.printf("Failed to mount the SD card.\n\r");
        return -1; // ends function with error status
    }
    else
        return 0;
}

int openDataFile() {
    fp = fopen("/fs/dataLog.txt", "w"); // Open file and prepare to write
    if (fp == NULL) {
        pc.printf("Failed to open file.\n\r");
        return -1;
    }
    // Write a header row
    fprintf(fp, "Time (s) \t Voltage (V)\n\r"); // Needs to be modified for your particular experiment
    return 0;
}

int closeDateFile() {  // Close the file and unmount the file system so the SD card is happy
    fclose(fp);
    fs.unmount();
    pc.printf("It is now safe to remove the memory card.\r\n");
    return 0;
}

void writeData(float firstThing, float secondThing) {  // Need to modify for your particular experiment 
    fprintf(fp, "%.2f \t %.2f\n\r", firstThing, secondThing);
}