Revision 2:02f003d025a7, committed 2022-07-19

Comitter:

ffxx68

Date:

Tue Jul 19 13:49:28 2022 +0000

Parent:

1:3488faedd0d1

Commit message:

SD Card handling added

Changed in this revision

--- a/SDFileSystem.cpp	Fri Jul 15 09:04:31 2022 +0000
+++ b/SDFileSystem.cpp	Tue Jul 19 13:49:28 2022 +0000
@@ -151,10 +151,10 @@
 #include "SDFileSystem.h"
 #include "mbed_debug.h"
 
-#define SD_COMMAND_TIMEOUT                      0x10/*5000*/
+#define SD_COMMAND_TIMEOUT                      15/*5000*/
 #define SD_CMD0_GO_IDLE_STATE_RETRIES           3
 #define SD_CMD0_GO_IDLE_STATE                   0x00
-#define SD_DBG                                  1
+#define SD_DBG                                  0
 
 SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
     FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs), _is_initialized(0) {
@@ -200,8 +200,6 @@
 int SDFileSystem::_go_idle_state() {
     _spi.lock();
     
-
-    
     int cmd_arg = 0;    /* CMD0 argument is just "stuff bits"*/
 
     /* Resetting the MCU SPI master may not reset the on-board SDCard, in which
@@ -211,7 +209,7 @@
      * the command overcomes this situation. */
     for (int num_retries = 0; num_retries < SD_CMD0_GO_IDLE_STATE_RETRIES; num_retries++) {
         
-        // Set to SCK for initialisation, and clock card with cs = 1
+        // Set to SCK for initialisation, and clock card with CS high
         _cs = 1;
         // Initial delay 
         wait_us (1000);
@@ -220,8 +218,9 @@
             _spi.write(0xFF);
         }
         
-        /* send a CMD0, with /CS asserted */
+        /* send a CMD0, with /CS asserted low */
         _cs = 0;
+        wait_us (1000);
         _spi.write(0x40 | SD_CMD0_GO_IDLE_STATE);
         _spi.write(cmd_arg >> 24);
         _spi.write(cmd_arg >> 16);
@@ -242,7 +241,7 @@
                 _spi.unlock();
                 return response;
             }
-                
+            wait_us(1000);    
         }
     }
     _cs = 1;