Nucleo-L476RG using SD-CARD library. The program is functioning but might get problem if you update the mbed. In two different times I got problem with mbed library as no SPI clock was generated. At the time I publish this library the mbed is broken.

Dependencies:   SDFileSystem

Revision:
0:fdd58267bc13
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Apr 07 10:33:54 2017 +0000
@@ -0,0 +1,34 @@
+#include "mbed.h"
+#include "SDFileSystem.h"
+//Nucleo L476RG_SDCARD test
+
+
+
+/*              SD:                Description             nucleo           PINNR (from top to down of the right-connector-left pins):
+                1                   CS                     PB_6              9  
+                2                   MOSI                   PA_7              8
+                3                   GND                    GND
+                4                   3.3V                   3.3V
+                5                   SCLK                   PA_5              6                  
+                6                   -
+                7                   MISO                   PA_6              7
+                8
+                
+*/
+//              MOSI, MISO, SCLK, CS, name
+SDFileSystem sd(PA_7, PA_6, PA_5, PB_6, "sd");
+
+
+int main() {
+    printf("\nWait for new connection...\n");
+    
+    mkdir("/sd/mydir", 0777);
+    printf("\nDirectory created\n");
+    FILE *fp = fopen("/sd/mydir/sdtest.txt", "w");
+    if(fp == NULL) {
+        printf("Could not open file for write\n");
+    }
+    fprintf(fp, "Hello fun SD Card World!");
+    fclose(fp); 
+    printf("Text written to the SD-CARD\n");
+}