Major update to version 2.0.0

Author: greiman

LICENSE.md

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2011..2017 Bill Greiman
+Copyright (c) 2011..2020 Bill Greiman
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,42 +1,98 @@
-The Arduino SdFat library provides read/write access to FAT16/FAT32
-file systems on SD/SDHC flash cards.
+### Warning: This is SdFat Version 2.
 
-SdFat requires Arduino 1.6x or greater.
+Earlier releases of Version 1 are here:
 
-Key changes:
+https://github.com/greiman/SdFat/releases
 
-Support for multiple SPI ports now uses a pointer to a SPIClass object.
+SdFat Version 2 supports FAT16/FAT32 and exFAT SD cards. It is mostly
+backward compatible with SdFat Version 1 for FAT16/FAT32 cards.
 
-See the STM32Test example.
+exFAT supports files larger than 4GB so files sizes and positions are
+type uint64_t for classes that support exFAT.
+
+exFAT has many features not available in FAT16/FAT32.  exFAT has excellent
+support for contiguous files on flash devices and supports preallocation.
+
+If the SD card is the only SPI device, use dedicated SPI mode. This can
+greatly improve performance. See the bench example.
+
+Here is write performance for an old, 2011, card on a Due board.
+```
+Shared SPI:
+write speed and latency
+speed,max,min,avg
+KB/Sec,usec,usec,usec
+294.45,24944,1398,1737
+
+Dedicated SPI:
+write speed and latency
+speed,max,min,avg
+KB/Sec,usec,usec,usec
+3965.11,16733,110,127
+```
+The default version of SdFatConfig.h enables support for dedicated SPI and
+optimized access to contiguous files.  This makes SdFat Version 2 slightly
+larger than Version 1.  If these features are disabled, Version 2 is smaller
+than Version 1.
+
+The types for the classes SdFat and File are defined in SdFatConfig.h.
+The default version of SdFatConfig.h defines SdFat to only support FAT16/FAT32.
+SdFat and File are defined in terms of more basic classes by typedefs.  You
+can use these basic classes in applications.
+
+Support for exFAT requires a substantial amount of flash.  Here are sizes on
+an UNO for a simple program that opens a file, prints one line, and closes
+the file.
+```
+FAT16/FAT32 only: 9780 bytes flash, 875 bytes SRAM.
+
+exFAT only: 13830 bytes flash, 938 bytes SRAM.
+
+FAT16/FAT32/exFAT: 19326 bytes flash, 928 bytes SRAM.
 ```
-explicit SdFat(SPIClass* spiPort);
-\\ or
-explicit SdFatEX(SPIClass* spiPort);
+The section below of SdFatConfig.h has been edited to uses FAT16/FAT32 for
+small AVR boards and FAT16/FAT32/exFAT for all other boards.
 ```
+/**
+ * File types for SdFat, File, SdFile, SdBaseFile, fstream,
+ * ifstream, and ofstream.
+ *
+ * Set SDFAT_FILE_TYPE to:
+ *
+ * 1 for FAT16/FAT32, 2 for exFAT, 3 for FAT16/FAT32 and exFAT.
+ */
+#if defined(__AVR__) && FLASHEND < 0X8000
+// FAT16/FAT32 for 32K AVR boards.
+#define SDFAT_FILE_TYPE 1
+#else  // defined(__AVR__) && FLASHEND < 0X8000
+// FAT16/FAT32 and exFAT for all other boards.
+#define SDFAT_FILE_TYPE 3
+#endif  // defined(__AVR__) && FLASHEND < 0X8000
+```
+The SdBaseFile class has no Arduino Stream or Print support.
+
+The File class is derived from Stream and SdBaseFile.
 
-Open flags now follow POSIX conventions.  O_RDONLY is the same as O_READ and O_WRONLY is the
-same as O_WRITE. One and only one of of the mode flags, O_RDONLY, O_RDWR, or
-O_WRONLY is required.
- 
-Open flags for Particle Gen3 and ARM boards are now defined by fcntl.h.
-See SdFatConfig.h for options.
+The SdFile class is derived from SdBaseFile and Print.
 
-Support for particle Gen3 devices.
+Please try the examples.  Start with SdInfo, bench, and ExFatLogger.
 
-New cluster allocation algorithm.
+To use SdFat Version 2, unzip the download file, rename the library folder
+SdFat and place the SdFat folder into the libraries sub-folder in your main
+sketch folder.
 
-Please read changes.txt and the html documentation in the extras folder for more information.
+For more information see the Manual installation section of this guide:
 
-Please report problems as issues.
+http://arduino.cc/en/Guide/Libraries
 
 A number of configuration options can be set by editing SdFatConfig.h
-define macros.  See the html documentation for details
+define macros.  See the html documentation File tab for details.
+
+Please read the html documentation for this library in SdFat/doc/SdFat.html.
+Start with the  Main Page.  Next go to the Classes tab and read the
+documentation for the classes SdFat32, SdExFat, SdFs, File32, ExFile, FsFile.
 
-Please read the html documentation for this library.  Start with
-html/index.html and read the Main Page.  Next go to the Classes tab and
-read the documentation for the classes SdFat, SdFatEX, SdBaseFile,
-SdFile, File, StdioStream, ifstream, ofstream, and others.
- 
-Please continue by reading the html documentation in SdFat/extras/html
+The SdFat and File classes are defined in terms of the above classes by
+typedefs. Edit SdFatConfig.h to select class options.
 
-Updated 28 Dec 2018
+Please continue by reading the html documentation in the SdFat/doc folder.