File content as of revision 3:6085916c9d74:

#include "mbed.h"
#include "SDFileSystem.h"
#include "debug.h"
//#include "main.h"

int sd_append(char*);

DigitalIn sdDetect(PTE6,PullDown);      // SD Detect Pin


SDFileSystem sd(PTE3, PTE1, PTE2, PTE4, "sd"); // MOSI, MISO, SCK, CS
FILE *fp;
//Serial pc(USBTX, USBRX);
char buffer[1024];

double utc = 123456.34;
double mg = 123.4;
double la = 12345.67;

int sd_append(char* CSVOutput) {
    
    D(printf("Booting... SD Preset?=%d\r\n",sdDetect.read()));
    
    // Test to see if SD card is present, if not return.
    if (sdDetect == NULL){
        D(printf("No SD card present\r\n"));
        return -1;
    }
    
    
    D(printf("Initializing \r\n"));

/*
    fp = fopen("/sd/metaData.csv", "r");
    if (fp != NULL) {
        fclose(fp);
        //remove("/sd/hello.txt");
        D(printf("Could not open file\n"));
        return -1;
    }
*/

    D(printf("Appending data to the sd card \r\n"));
    fp = fopen("/sd/metaData.csv", "a");
    if (fp == NULL) {
        D(printf("Unable to write the file \r\n"));
    } else {
        fprintf(fp, "%s", CSVOutput);
        fclose(fp);
        D(printf("File successfully written! \r\n"));
        return -1;
    }

/*
    printf("\nReading data from the SD card. \r\n");
    fp = fopen("/sd/metaData.csv", "r");
    if (fp != NULL) {
        int size = fread(buffer, sizeof(char), 1024, fp);
        printf("Number of data read: %d, text from hello.txt file: %s \r\n", size, buffer);
        fclose(fp);
    }
    //printf("End of Lab 4. \n");
*/    
    return 0;        
}