mbed-os storage access example.

Dependencies:   SDBlockDevice_GR_PEACH USBHost_custom

This is a sample for using USB memory and SD card in mbed-os 5.4 or later version.

Import program

00001 #include "mbed.h"
00002 #include "FATFileSystem.h"
00003 #include "SDBlockDevice_GR_PEACH.h"
00004 #include "USBHostMSD.h"
00005 
00006 int main() {
00007     int i = 0;
00008     int storage_type = 0;
00009     char storage_str[16];
00010 
00011     FATFileSystem fs("storage");
00012     SDBlockDevice_GR_PEACH sd;
00013     USBHostMSD usb;
00014 
00015     while(1) {
00016         // try to connect a storage device
00017         while (1) {
00018             if (sd.connect()) {
00019                 storage_type = 0; // SD
00020                 strcpy(storage_str, "SD card");
00021                 fs.mount(&sd);
00022                 break;
00023             }
00024             if (usb.connect()) {
00025                 storage_type = 1; // USB
00026                 strcpy(storage_str, "USB memory");
00027                 fs.mount(&usb);
00028                 break;
00029             }
00030             Thread::wait(500);
00031         }
00032 
00033         // in a loop, append a file
00034         // if the device is disconnected, we try to connect it again
00035         while(1) {
00036             // append a file
00037             FILE * fp = fopen("/storage/test1.txt", "a");
00038 
00039             if (fp != NULL) {
00040                 fprintf(fp, "Hello %s World: %d!\r\n", storage_str, i++);
00041                 printf("Goodbye World!\r\n");
00042                 fclose(fp);
00043             } else {
00044                 printf("FILE == NULL\r\n");
00045             }
00046             Thread::wait(500);
00047 
00048             // if device disconnected, try to connect again
00049             if (storage_type == 0) {
00050                 if (!sd.connected())  break;
00051             } else {
00052                 if (!usb.connected()) break;
00053             }
00054         }
00055         fs.unmount();
00056     }
00057 }

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