# SdFat: ArduinoSdFat/libraries/SdFat/src/SdFatConfig.h File Reference

SdFatConfig.h File Reference

configuration definitions More...

`#include <stdint.h>`
`#include "Arduino.h"`
Include dependency graph for SdFatConfig.h:
This graph shows which files directly or indirectly include this file:

## Macros

#define | CHECK_FLASH_PROGRAMMING 1
#define | DESTRUCTOR_CLOSES_FILE 0
#define | ENABLE_ARDUINO_FEATURES 1
#define | ENABLE_ARDUINO_SERIAL 1
#define | ENABLE_ARDUINO_STRING 1
#define | ENABLE_DEDICATED_SPI 1
#define | ENDL_CALLS_FLUSH 0
#define | FAT12_SUPPORT 0
#define | HAS_SDIO_CLASS 0
#define | INCLUDE_SDIOS 0
#define | MAINTAIN_FREE_CLUSTER_COUNT 0
#define | SD_CHIP_SELECT_MODE 0
#define | SD_HAS_CUSTOM_SPI 0
#define | SD_MAX_INIT_RATE_KHZ 400
#define | SDFAT_FILE_TYPE 1
#define | SPI_DRIVER_SELECT 0
#define | USE_BLOCK_DEVICE_INTERFACE 0
#define | USE_EXFAT_BITMAP_CACHE 0
#define | USE_FAT_FILE_FLAG_CONTIGUOUS 1
#define | USE_FCNTL_H 0
#define | USE_LONG_FILE_NAMES 1
#define | USE_MULTI_SECTOR_IO 1
#define | USE_SD_CRC 0
#define | USE_SEPARATE_FAT_CACHE 0
#define | USE_SIMPLE_LITTLE_ENDIAN 1
#define | WDT_YIELD_TIME_MILLIS 0

## Typedefs

typedef uint8_t | SdCsPin_t

## Detailed Description

configuration definitions

Copyright (c) 2011-2019 Bill Greiman This file is part of the SdFat library for SD memory cards.

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

## Macro Definition Documentation

## CHECK_FLASH_PROGRAMMING

#define CHECK_FLASH_PROGRAMMING 1

If CHECK_FLASH_PROGRAMMING is zero, overlap of single sector flash programming and other operations will be allowed for faster write performance.

Some cards will not sleep in low power mode unless CHECK_FLASH_PROGRAMMING is non-zero.

## DESTRUCTOR_CLOSES_FILE

#define DESTRUCTOR_CLOSES_FILE 0

Set DESTRUCTOR_CLOSES_FILE nonzero to close a file in its destructor.

Causes use of lots of heap in ARM.

## ENABLE_ARDUINO_FEATURES

#define ENABLE_ARDUINO_FEATURES 1

For Debug - must be one

## ENABLE_ARDUINO_SERIAL

#define ENABLE_ARDUINO_SERIAL 1

For Debug - must be one

## ENABLE_ARDUINO_STRING

#define ENABLE_ARDUINO_STRING 1

For Debug - must be one

## ENABLE_DEDICATED_SPI

#define ENABLE_DEDICATED_SPI 1

Set ENABLE_DEDICATED_SPI to enable dedicated use of the SPI bus. Selecting dedicated SPI in SdSpiConfig() will produce better performance by using very large multi-block transfers to and from the SD card.

Enabling dedicated SPI will cost some extra flash and RAM.

## ENDL_CALLS_FLUSH

#define ENDL_CALLS_FLUSH 0

Call flush for endl if ENDL_CALLS_FLUSH is nonzero

The standard for iostreams is to call flush. This is very costly for SdFat. Each call to flush causes 2048 bytes of I/O to the SD.

SdFat has a single 512 byte buffer for SD I/O so it must write the current data sector to the SD, read the directory sector from the SD, update the directory entry, write the directory sector to the SD and read the data sector back into the buffer.

The SD flash memory controller is not designed for this many rewrites so performance may be reduced by more than a factor of 100.

If ENDL_CALLS_FLUSH is zero, you must call flush and/or close to force all data to be written to the SD.

## FAT12_SUPPORT

#define FAT12_SUPPORT 0

Set FAT12_SUPPORT nonzero to enable use if FAT12 volumes. FAT12 has not been well tested and requires additional flash.

## HAS_SDIO_CLASS

#define HAS_SDIO_CLASS 0

Default is no SDIO.

## INCLUDE_SDIOS

#define INCLUDE_SDIOS 0

Set INCLUDE_SDIOS nonzero to include sdios.h in SdFat.h. sdios.h provides C++ style IO Streams.

## MAINTAIN_FREE_CLUSTER_COUNT

#define MAINTAIN_FREE_CLUSTER_COUNT 0

Set MAINTAIN_FREE_CLUSTER_COUNT nonzero to keep the count of free clusters updated. This will increase the speed of the freeClusterCount() call after the first call. Extra flash will be required.

## SD_CHIP_SELECT_MODE

#define SD_CHIP_SELECT_MODE 0

SD_CHIP_SELECT_MODE defines how the functions void sdCsInit(SdCsPin_t pin) {pinMode(pin, OUTPUT);} and void sdCsWrite(SdCsPin_t pin, bool level) {digitalWrite(pin, level);} are defined.

0 - Internal definition is a strong symbol and can't be replaced.

1 - Internal definition is a weak symbol and can be replaced.

2 - No internal definition and must be defined in the application.

## SD_HAS_CUSTOM_SPI

#define SD_HAS_CUSTOM_SPI 0

Enable SDIO driver if available. Determine the default SPI configuration.

## SD_MAX_INIT_RATE_KHZ

#define SD_MAX_INIT_RATE_KHZ 400

SD maximum initialization clock rate.

## SDFAT_FILE_TYPE

#define SDFAT_FILE_TYPE 1

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.

## SPI_DRIVER_SELECT

#define SPI_DRIVER_SELECT 0

If the symbol SPI_DRIVER_SELECT is:

0 - An optimized custom SPI driver is used if it exists else the standard library driver is used.

1 - The standard library driver is always used.

2 - The software SPI driver is always used.

3 - Experimental external SPI driver hook.

## USE_BLOCK_DEVICE_INTERFACE

#define USE_BLOCK_DEVICE_INTERFACE 0

Set USE_BLOCK_DEVICE_INTERFACE nonzero to use generic of block device

## USE_EXFAT_BITMAP_CACHE

#define USE_EXFAT_BITMAP_CACHE 0

Set USE_EXFAT_BITMAP_CACHE nonzero to use a second 512 byte cache for exFAT bitmap entries. This improves performance for large writes that are not a multiple of 512 bytes.

## USE_FAT_FILE_FLAG_CONTIGUOUS

#define USE_FAT_FILE_FLAG_CONTIGUOUS 1

Optimize access to contiguous files. Experimental - set nonzero to enable.

## USE_FCNTL_H

#define USE_FCNTL_H 0

If the symbol USE_FCNTL_H is nonzero, open flags for access modes O_RDONLY, O_WRONLY, O_RDWR and the open modifiers O_APPEND, O_CREAT, O_EXCL, O_SYNC will be defined by including the system file fcntl.h.

## USE_LONG_FILE_NAMES

#define USE_LONG_FILE_NAMES 1

Set USE_LONG_FILE_NAMES nonzero to use long file names (LFN) in FAT16/FAT32. exFAT always uses long file names.

Long File Name are limited to a maximum length of 255 characters.

This implementation allows 7-bit characters in the range 0X20 to 0X7E except the following characters are not allowed:

< (less than)

> (greater than)

: (colon) " (double quote) / (forward slash) \ (backslash) | (vertical bar or pipe) ? (question mark)

- (asterisk)

## USE_MULTI_SECTOR_IO

#define USE_MULTI_SECTOR_IO 1

Set USE_MULTI_SECTOR_IO nonzero to use multi-sector SD read/write.

Don't use mult-sector read/write on small AVR boards.

## USE_SD_CRC

#define USE_SD_CRC 0

To enable SD card CRC checking for SPI, set USE_SD_CRC nonzero.

Set USE_SD_CRC to 1 to use a smaller CRC-CCITT function. This function is slower for AVR but may be fast for ARM and other processors.

Set USE_SD_CRC to 2 to used a larger table driven CRC-CCITT function. This function is faster for AVR but may be slower for ARM and other processors.

## USE_SEPARATE_FAT_CACHE

#define USE_SEPARATE_FAT_CACHE 0

Set USE_SEPARATE_FAT_CACHE nonzero to use a second 512 byte cache for FAT16/FAT32 table entries. This improves performance for large writes that are not a multiple of 512 bytes.

## USE_SIMPLE_LITTLE_ENDIAN

#define USE_SIMPLE_LITTLE_ENDIAN 1

Set USE_SIMPLE_LITTLE_ENDIAN nonzero for little endian processors with no memory alignment restrictions.

## WDT_YIELD_TIME_MILLIS

#define WDT_YIELD_TIME_MILLIS 0

Handle Watchdog Timer for WiFi modules.

Yield will be called before accessing the SPI bus if it has been more than WDT_YIELD_TIME_MILLIS milliseconds since the last yield call by SdFat.

## Typedef Documentation

## SdCsPin_t

typedef uint8_t SdCsPin_t

Type for card chip select pin.