The program will open a file called test.txt in the root of the SD card, and will create one if it does not exist. It will then write "one two three four five" in the .txt file. It will then read the text and output the result. You will need a terminal application (I recommend PuTTy) in order to see the outputs. The current program overwrites anything that was previous on the SD card. To prevent this, change the "w" to "a" during the writing process. This changes the instruction from a 'write' to an 'append'.
Dependencies: SDFileSystem mbed
Fork of
SDFileSystem_HelloWorld
by 
mbed official
Diff: main.cpp
- Revision:
- 1:2cf8f0893afd
- Parent:
- 0:bdbd3d6fc5d5
--- a/main.cpp Fri Dec 07 11:25:01 2012 +0000
+++ b/main.cpp Thu Jul 24 12:55:11 2014 +0000
@@ -1,19 +1,42 @@
#include "mbed.h"
#include "SDFileSystem.h"
-SDFileSystem sd(p5, p6, p7, p8, "sd"); // the pinout on the mbed Cool Components workshop board
-
+SDFileSystem sd(PTE3, PTE1, PTE2, PTE4, "sd"); //mosi, miso, sclk, cs
+
+
+#define charlimit 100
+char words[charlimit];
+int n=0,c;
+
int main() {
- printf("Hello World!\n");
-
- mkdir("/sd/mydir", 0777);
+
+ //writing to SD card
+ printf("Opening SD card...\r\n");
+
+ FILE *fp = fopen("/sd/test.txt", "w");
+ if(fp == NULL) {
+ error("Could not open file for write!\r\n");
+ }
- FILE *fp = fopen("/sd/mydir/sdtest.txt", "w");
- if(fp == NULL) {
- error("Could not open file for write\n");
- }
- fprintf(fp, "Hello fun SD Card World!");
+ printf("Writing to SD card...\r\n");
+ fprintf(fp, "one two three four five\r\n");
fclose(fp);
+
+ //reading from SD card
+ FILE *fp1 =fopen("/sd/test.txt.", "r");
+ if(fp1==NULL){
+ error("Could not open file for read!\r\n");
+ }
+
+ printf("Reading from SD card...\r\n");
+
+ while((c=fgetc(fp1)) && c!=EOF){
+ words[n]=c;
+ n++;
+ }
+
+ printf("Read from SD card: %s",words);
+
+ fclose(fp1);
- printf("Goodbye World!\n");
}