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- Support has been added for the Arduino Due.
-
- You must connect your SD socket to the 6-pin "ISP connector". You must have short
- wires or a custom shield to run at full speed, 42 MHz.
-
- If you have problems use a lower SPI speed. You can also check for SPI
- errors by editing SdFatCobfig.h to enable CRC checking.
-
- You should be be able to use any digital pin for SD chip select. The default
- pin is SS which is pin 10 for Due.
-
- The default SPI rate is 42 MHz. You can set SD chip select and the SPI rate
- by calling:
-
- bool SdFat::begin(uint8_t chipSelectPin, uint8_t spiRateID);
-
- The second argument, spiRateID, sets the SCK rate and can be these symbols:
-
- SPI_FULL_SPEED - 42 MHz
-
- SPI_DIV3_SPEED - 28 MHz
-
- SPI_HALF_SPEED - 21 MHz
-
- SPI_DIV6_SPEED - 14 MHz
-
- SPI_QUARTER_SPEED 10.5 MHz
-
- SPI_EIGHTH_SPEED 5.25 MHz
-
- Large reads and writes use fast multi-block SD read/write commands. For optimal
- speed, use records that are a multiple of 512 bytes.
-
- Run the bench.ino example to explore large read/write speed.
-
- Replace this line:
-
- #define BUF_SIZE 100
-
- With a large size like this:
-
- #define BUF_SIZE 8192
-
- For best results the record size should be a power of two (512, 1024, 2048,
- 4096, 8192). In this case records will be aligned with FAT cluster boundaries.
-
- Since Due is fast, increase the test file size by editing this line:
-
- #define FILE_SIZE_MB 5
-
- Run the PrintBenchmark.ino example to compare text formatting speed of Due
- with AVR boards.
-
- A number of options are available to configure SPI for the Due board.
-
- You can use the standard SPI.h library by editing SdFatConfig.h and set
- USE_ARDUINO_SPI_LIBRARY nonzero. You must include SPI.h in your sketch.
-
- Several options can be set in Sd2Card.cpp in the USE_NATIVE_SAM3X_SPI
- section. These include USE_SAM3X_DMAC to control use of DMA and
- USE_SAM3X_BUS_MATRIX_FIX to change Bus Matrix operation. Most people
- will not need to change these.
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