teensy-sdfat/examples/SoftwareSpi/SoftwareSpi.ino

// An example of the SoftSpiDriver template class.
// This example is for an old Adafruit Data Logging Shield on a Mega.
// Software SPI is required on Mega since this shield connects to pins 10-13.
// This example will also run on an Uno and other boards using software SPI.
//
#include <SPI.h>
#include "SdFat.h"
#if SPI_DRIVER_SELECT == 2  // Must be set in SdFat/SdFatConfig.h

// SD_FAT_TYPE = 0 for SdFat/File as defined in SdFatConfig.h,
// 1 for FAT16/FAT32, 2 for exFAT, 3 for FAT16/FAT32 and exFAT.
#define SD_FAT_TYPE 0
//
// Chip select may be constant or RAM variable.
const uint8_t SD_CS_PIN = 10;
//
// Pin numbers in templates must be constants.
const uint8_t SOFT_MISO_PIN = 12;
const uint8_t SOFT_MOSI_PIN = 11;
const uint8_t SOFT_SCK_PIN  = 13;

// SdFat software SPI template
SoftSpiDriver<SOFT_MISO_PIN, SOFT_MOSI_PIN, SOFT_SCK_PIN> softSpi;
// Speed argument is ignored for software SPI.
#define SD_CONFIG SdSpiConfig(SD_CS_PIN, DEDICATED_SPI, SD_SCK_MHZ(0), &softSpi)

#if SD_FAT_TYPE == 0
SdFat sd;
File file;
#elif SD_FAT_TYPE == 1
SdFat32 sd;
File32 file;
#elif SD_FAT_TYPE == 2
SdExFat sd;
ExFile file;
#elif SD_FAT_TYPE == 3
SdFs sd;
FsFile file;
#else  // SD_FAT_TYPE
#error Invalid SD_FAT_TYPE
#endif  // SD_FAT_TYPE

void setup() {
  Serial.begin(9600);
  // Wait for USB Serial 
  while (!Serial) {
    SysCall::yield();
  }
  Serial.println("Type any character to start");
  while (!Serial.available()) {
    SysCall::yield();
  }

  if (!sd.begin(SD_CONFIG)) {
    sd.initErrorHalt();
  }

  if (!file.open("SoftSPI.txt", O_RDWR | O_CREAT)) {
    sd.errorHalt(F("open failed"));
  }
  file.println(F("This line was printed using software SPI."));

  file.rewind();
  
  while (file.available()) {
    Serial.write(file.read());
  }

  file.close();

  Serial.println(F("Done."));
}
//------------------------------------------------------------------------------
void loop() {}
#else  // SPI_DRIVER_SELECT
#error SPI_DRIVER_SELECT must be two in SdFat/SdFatConfig.h
#endif  //SPI_DRIVER_SELECT