diff --git a/test/Main_SdFat_format/Main_SdFat_format.ino b/test/Main_SdFat_format/Main_SdFat_format.ino
index cf39826..cd08709 100644
--- a/test/Main_SdFat_format/Main_SdFat_format.ino
+++ b/test/Main_SdFat_format/Main_SdFat_format.ino
@@ -28,7 +28,7 @@
 #include "diskio.h"
 
 // up to 11 characters
-#define DISK_LABEL    "EXT FLASH"
+#define DISK_LABEL "EXT FLASH"
 
 // for flashTransport definition
 //#include "flash_config.h"
@@ -39,55 +39,60 @@ Adafruit_FlashTransport_SPI flashTransport(EXTERNAL_FLASH_USE_CS, EXTERNAL_FLASH
 Adafruit_SPIFlash flash(&flashTransport);
 FatVolume fatfs;
 
-void format_fat12(void)
-{
-  // Working buffer for f_mkfs.
-  #ifdef __AVR__
-    uint8_t workbuf[512];
-  #else
-    uint8_t workbuf[4096];
-  #endif
+void format_fat12(void) {
+// Working buffer for f_mkfs.
+#ifdef __AVR__
+  uint8_t workbuf[512];
+#else
+  uint8_t workbuf[4096];
+#endif
 
   // Elm Cham's fatfs objects
   FATFS elmchamFatfs;
 
   // Make filesystem.
+  Serial.print(F("Make filesystem."));
   FRESULT r = f_mkfs("", FM_FAT, 0, workbuf, sizeof(workbuf));
   if (r != FR_OK) {
-    Serial.print(F("Error, f_mkfs failed with error code: ")); Serial.println(r, DEC);
-    while(1) yield();
+    Serial.print(F("Error, f_mkfs failed with error code: "));
+    Serial.println(r, DEC);
+    while (1) yield();
   }
 
   // mount to set disk label
+  Serial.print(F("mount to set disk label"));
   r = f_mount(&elmchamFatfs, "0:", 1);
   if (r != FR_OK) {
-    Serial.print(F("Error, f_mount failed with error code: ")); Serial.println(r, DEC);
-    while(1) yield();
+    Serial.print(F("Error, f_mount failed with error code: "));
+    Serial.println(r, DEC);
+    while (1) yield();
   }
 
   // Setting label
   Serial.println(F("Setting disk label to: " DISK_LABEL));
   r = f_setlabel(DISK_LABEL);
   if (r != FR_OK) {
-    Serial.print(F("Error, f_setlabel failed with error code: ")); Serial.println(r, DEC);
-    while(1) yield();
+    Serial.print(F("Error, f_setlabel failed with error code: "));
+    Serial.println(r, DEC);
+    while (1) yield();
   }
 
   // unmount
+  Serial.println(F("unmount"));
   f_unmount("0:");
 
   // sync to make sure all data is written to flash
+  Serial.println(F("sync to make sure all data is written to flash"));
   flash.syncBlocks();
 
   Serial.println(F("Formatted flash!"));
 }
 
-void check_fat12(void)
-{
+void check_fat12(void) {
   // Check new filesystem
   if (!fatfs.begin(&flash)) {
     Serial.println(F("Error, failed to mount newly formatted filesystem!"));
-    while(1) delay(1);
+    while (1) delay(1);
   }
 }
 
@@ -96,17 +101,20 @@ void setup() {
   // Initialize serial port and wait for it to open before continuing.
   Serial.begin(115200);
   while (!Serial) delay(100);
-  
+
   Serial.println(F("Adafruit SPI Flash FatFs Format Example"));
 
   // Initialize flash library and check its chip ID.
   if (!flash.begin()) {
     Serial.println(F("Error, failed to initialize flash chip!"));
-    while(1) yield();
+    while (1) yield();
   }
 
-  Serial.print(F("Flash chip JEDEC ID: 0x")); Serial.println(flash.getJEDECID(), HEX);
-  Serial.print(F("Flash size: ")); Serial.print(flash.size() / 1024); Serial.println(F(" KB"));
+  Serial.print(F("Flash chip JEDEC ID: 0x"));
+  Serial.println(flash.getJEDECID(), HEX);
+  Serial.print(F("Flash size: "));
+  Serial.print(flash.size() / 1024);
+  Serial.println(F(" KB"));
 
   // Uncomment to flash LED while writing to flash
   // flash.setIndicator(LED_BUILTIN, true);
@@ -118,7 +126,7 @@ void setup() {
     Serial.println(F("This sketch will ERASE ALL DATA on the flash chip and format it with a new filesystem!"));
     Serial.println(F("Type OK (all caps) and press enter to continue."));
     Serial.println(F("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"));
-  } while ( !Serial.find((char*) "OK"));
+  } while (!Serial.find((char *)"OK"));
 
   // Call fatfs begin and passed flash object to initialize file system
   Serial.println(F("Creating and formatting FAT filesystem (this takes ~60 seconds)..."));
@@ -139,72 +147,64 @@ void loop() {
 //--------------------------------------------------------------------+
 // fatfs diskio
 //--------------------------------------------------------------------+
-extern "C"
-{
-
-DSTATUS disk_status ( BYTE pdrv )
-{
-  (void) pdrv;
-	return 0;
-}
+extern "C" {
 
-DSTATUS disk_initialize ( BYTE pdrv )
-{
-  (void) pdrv;
-	return 0;
-}
+  DSTATUS disk_status(BYTE pdrv) {
+    (void)pdrv;
+    return 0;
+  }
 
-DRESULT disk_read (
-	BYTE pdrv,		/* Physical drive nmuber to identify the drive */
-	BYTE *buff,		/* Data buffer to store read data */
-	DWORD sector,	/* Start sector in LBA */
-	UINT count		/* Number of sectors to read */
-)
-{
-  (void) pdrv;
-	return flash.readBlocks(sector, buff, count) ? RES_OK : RES_ERROR;
-}
+  DSTATUS disk_initialize(BYTE pdrv) {
+    (void)pdrv;
+    return 0;
+  }
 
-DRESULT disk_write (
-	BYTE pdrv,			/* Physical drive nmuber to identify the drive */
-	const BYTE *buff,	/* Data to be written */
-	DWORD sector,		/* Start sector in LBA */
-	UINT count			/* Number of sectors to write */
-)
-{
-  (void) pdrv;
-  return flash.writeBlocks(sector, buff, count) ? RES_OK : RES_ERROR;
-}
+  DRESULT disk_read(
+    BYTE pdrv,    /* Physical drive nmuber to identify the drive */
+    BYTE *buff,   /* Data buffer to store read data */
+    DWORD sector, /* Start sector in LBA */
+    UINT count    /* Number of sectors to read */
+  ) {
+    (void)pdrv;
+    return flash.readBlocks(sector, buff, count) ? RES_OK : RES_ERROR;
+  }
 
-DRESULT disk_ioctl (
-	BYTE pdrv,		/* Physical drive nmuber (0..) */
-	BYTE cmd,		/* Control code */
-	void *buff		/* Buffer to send/receive control data */
-)
-{
-  (void) pdrv;
-
-  switch ( cmd )
-  {
-    case CTRL_SYNC:
-      flash.syncBlocks();
-      return RES_OK;
-
-    case GET_SECTOR_COUNT:
-      *((DWORD*) buff) = flash.size()/512;
-      return RES_OK;
-
-    case GET_SECTOR_SIZE:
-      *((WORD*) buff) = 512;
-      return RES_OK;
-
-    case GET_BLOCK_SIZE:
-      *((DWORD*) buff) = 8;    // erase block size in units of sector size
-      return RES_OK;
-
-    default:
-      return RES_PARERR;
+  DRESULT disk_write(
+    BYTE pdrv,        /* Physical drive nmuber to identify the drive */
+    const BYTE *buff, /* Data to be written */
+    DWORD sector,     /* Start sector in LBA */
+    UINT count        /* Number of sectors to write */
+  ) {
+    (void)pdrv;
+    return flash.writeBlocks(sector, buff, count) ? RES_OK : RES_ERROR;
   }
-}
 
+  DRESULT disk_ioctl(
+    BYTE pdrv, /* Physical drive nmuber (0..) */
+    BYTE cmd,  /* Control code */
+    void *buff /* Buffer to send/receive control data */
+  ) {
+    (void)pdrv;
+
+    switch (cmd) {
+      case CTRL_SYNC:
+        flash.syncBlocks();
+        return RES_OK;
+
+      case GET_SECTOR_COUNT:
+        *((DWORD *)buff) = flash.size() / 512;
+        return RES_OK;
+
+      case GET_SECTOR_SIZE:
+        *((WORD *)buff) = 512;
+        return RES_OK;
+
+      case GET_BLOCK_SIZE:
+        *((DWORD *)buff) = 8;  // erase block size in units of sector size
+        return RES_OK;
+
+      default:
+        return RES_PARERR;
+    }
+  }
 }