Huseyin Buyukesmeli / Mbed 2 deprecated DISCO-F746NG_uSD

F746NG fatfs and micro sd example

Dependencies:   BSP_DISCO_F746NG FatFS mbed

This is a quick and dirty example about how to use micro sd card module with FatFs on STM32746G Discovery board. I simply use the FatFs library downloaded with DFP for STM32F7. The project shows how to read PPM image file from sd card, display on LCD and writing image to sd card.

Files at this revision

API Documentation at this revision

Revision 2:19c2835ce409, committed 2018-02-04

Comitter:
buyukesmeli
Date:
Sun Feb 04 10:12:09 2018 +0000
Parent:
1:28e2f24b11b3
Commit message:
Color and output image bugs are fixed

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file 
--- a/main.cpp	Sat Feb 03 14:43:35 2018 +0000
+++ b/main.cpp	Sun Feb 04 10:12:09 2018 +0000
@@ -12,11 +12,11 @@
 #define SD_IN_BUFFER    0xC0140000
 #define SD_OUT_BUFFER   0xC0280000
 
-FATFS SDFatFs;  
-FIL MyFile;  
+FATFS SDFatFs;
+FIL MyFile;
 
 
- 
+
 
 static void LCD_LL_ConvertFrameToARGB8888(void *pSrc, void *pDst);
 static void LCD_LL_ConvertFrameToRGB888(void *pSrc, void *pDst);
@@ -25,12 +25,11 @@
 
 Serial pc(USBTX, USBRX);
 uint32_t i = 0, image_width = 0, image_height = 0;
-const char image_header[] = "P6\n# Generated by STM32\n272 480\n255\n";
+const char image_header[] = "P6\n# Generated by STM32\n480 272\n255\n";
 
 char SDPath[4];
 char text [40];
 char c;
-
 int main(void)
 {
     FRESULT res;
@@ -45,17 +44,17 @@
     BSP_LCD_DisplayOn();
 
     FATFS_LinkDriver(&SD_Driver, SDPath);
-    
+
     res = f_mount(&SDFatFs, (TCHAR const*)SDPath, 0);
     if(res!= FR_OK)
         pc.printf("Failed to mount SD\n");
-        
+
     res = f_open(&MyFile, "image.ppm",  FA_READ);
     if(res!= FR_OK)
         pc.printf("Failed to open file\n");
-        
-    while(1) {
-        
+    
+    // Read image header and get image size
+    while(res==FR_OK) {
         res = f_read(&MyFile, &c, 1, (UINT*)&bytesread);
         if (c!='#')
             line_cnt++;
@@ -87,35 +86,53 @@
             break;
 
     }
-    
+
     if(image_width != 480 || image_height != 272)
-        pc.printf("Image size should be 272x480");
+        pc.printf("Image size should be 480x272");
+        
+    // Read image as 512 byte blocks
+    for(i = 0; i < image_width*image_width*3; i = i + 512) {
+        res = f_read(&MyFile, (uint8_t *)(SD_IN_BUFFER+i) , 512, (UINT*)&bytesread);
+    }
     
-    for(i = 0; i < image_width*image_width*3; i = i + 512) {
-        res = f_read(&MyFile, (void *)(SD_IN_BUFFER+i) , 512, (UINT*)&bytesread);
+    // Correct color order
+    for(i = 0; i < image_width*image_width*3; i = i + 3) {
+        c = *(char *)(SD_IN_BUFFER+i+2);
+        *(char *)(SD_IN_BUFFER+i+2)= *(char *)(SD_IN_BUFFER+i);
+        *(char *)(SD_IN_BUFFER+i) = c;
     }
     f_close(&MyFile);
     
+    // Print image on LCD
     LCD_LL_ConvertFrameToARGB8888((uint32_t *)(SD_IN_BUFFER), (uint32_t *)(FRAME_BUFFER));
+
+    
+    // Transfer image to a buffer
+    LCD_LL_ConvertFrameToRGB888((uint32_t *)(FRAME_BUFFER), (uint32_t *)(SD_OUT_BUFFER));
     
-
-    LCD_LL_ConvertFrameToRGB888((uint32_t *)(FRAME_BUFFER), (uint32_t *)(SD_OUT_BUFFER));
+    // Correct color order
+    for(i = 0; i < image_width*image_width*3; i = i + 3) {
+        c = *(char *)(SD_OUT_BUFFER+i+2);
+        *(char *)(SD_OUT_BUFFER+i+2)= *(char *)(SD_OUT_BUFFER+i);
+        *(char *)(SD_OUT_BUFFER+i) = c;
+    }
     
     res = f_open(&MyFile, "image_ou.ppm",   FA_CREATE_ALWAYS | FA_WRITE);
     if(res!= FR_OK)
         pc.printf("Failed to open file\n");
 
-
-    res = f_write(&MyFile, image_header, 15, &bytesread);
+    // Write image header
+    res = f_write(&MyFile, image_header, sizeof(image_header), &bytesread);
     if(res!= FR_OK)
         pc.printf("Failed to write file 1\n");
         
+    // Write image as 512 byte blocks
     for(i = 0; i < 480*272*3; i = i + 512) {
         res = f_write(&MyFile, (uint8_t *)(SD_OUT_BUFFER+i), 512, &bytesread);
         if(res!= FR_OK)
             pc.printf("Failed to write file\n");
     }
-    
+
     pc.printf("Done!\n");
     f_close(&MyFile);
     FATFS_UnLinkDriver(SDPath);