Revision 3:deefd66fdc9e, committed 2015-03-04

Comitter:

joshwilkins2013

Date:

Wed Mar 04 00:32:29 2015 +0000

Parent:

2:41dd6f412728

Commit message:

Simple SD card test outputing floats in a loop

Changed in this revision

diff -r 41dd6f412728 -r deefd66fdc9e main.cpp
--- a/main.cpp	Mon Apr 07 19:36:26 2014 +0000
+++ b/main.cpp	Wed Mar 04 00:32:29 2015 +0000
@@ -2,37 +2,35 @@
 #include "SDFileSystem.h"
 
 SDFileSystem sd(PTE3, PTE1, PTE2, PTE4, "sd"); // MOSI, MISO, SCK, CS
+
 Serial pc(USBTX, USBRX);
-FILE *fp;
-char buffer[1024];
+
+FILE *Data;   // Creates name of file
+char buffer[1024];  // Buffer size (# of characters)
 
 int main() {
     pc.printf("Initializing \n");
-    wait(2);
-
-    fp = fopen("/sd/hello.txt", "r");
-    if (fp != NULL) {
-        fclose(fp);
-        remove("/sd/hello.txt");
-        pc.printf("Remove an existing file with the same name \n");
+    
+    float x = 214;
+    double y = 200;
+    
+    Data = fopen("/sd/Data.txt", "r");   // Opens file if it exists, r means read
+    if (Data != NULL) remove("/sd/Data.txt"); // If it does close it then remove it
+    fclose(Data); 
+    
+    Data = fopen("/sd/Data.txt", "w"); // w means write
+    for(int i=0; i<4; i++){
+        if (Data == NULL) pc.printf("Unable to write the file \n\r");  // This chunk for writing to file on SD card
+        else fprintf(Data, "%f\t%f\n",x,y);  // can read float or double not int (only checked these three types)
+        x++;
+        y--;
     }
-
-    printf("\nWriting data to the sd card \n");
-    fp = fopen("/sd/hello.txt", "w");
-    if (fp == NULL) {
-        pc.printf("Unable to write the file \n");
-    } else {
-        fprintf(fp, "mbed SDCard application!");
-        fclose(fp);
-        pc.printf("File successfully written! \n");
+    fclose(Data);
+    
+    Data = fopen("/sd/Data.txt", "r");
+    if (Data != NULL) {
+        int size = fread(buffer, sizeof(char), 1024, Data); // This chunk for reading the file on the SD card
+        printf("%s\n", buffer); // can read float or double not int (only checked these three types)
     }
-
-    printf("\nReading data from the SD card. \n");
-    fp = fopen("/sd/hello.txt", "r");
-    if (fp != NULL) {
-        int size = fread(buffer, sizeof(char), 1024, fp);
-        printf("Number of data read: %d, text from hello.txt file: %s \n", size, buffer);
-        fclose(fp);
-    }
-    printf("End of Lab 4. \n");
+    fclose(Data);
 }