Software SPI is now supported on AVR, Due, and Teensy 3.x boards. Edit these variables in SdFatConfig.h to enable Software SPI. //------------------------------------------------------------------------------ /** * Define AVR_SOF_SPI nonzero to use software SPI on all AVR Arduinos. */ #define AVR_SOFT_SPI 0 //------------------------------------------------------------------------------ /** * Define DUE_SOFT_SPI nonzero to use software SPI on Due Arduinos. */ #define DUE_SOFT_SPI 0 //------------------------------------------------------------------------------ /** * Define LEONARDO_SOFT_SPI nonzero to use software SPI on Leonardo Arduinos. * LEONARDO_SOFT_SPI allows an unmodified 328 Shield to be used * on Leonardo Arduinos. */ #define LEONARDO_SOFT_SPI 0 //------------------------------------------------------------------------------ /** * Define MEGA_SOFT_SPI nonzero to use software SPI on Mega Arduinos. * MEGA_SOFT_SPI allows an unmodified 328 Shield to be used * on Mega Arduinos. */ #define MEGA_SOFT_SPI 0 //------------------------------------------------------------------------------ /** * Set TEENSY3_SOFT_SPI nonzero to use software SPI on Teensy 3.x boards. */ #define TEENSY3_SOFT_SPI 0 //------------------------------------------------------------------------------ /** * Define software SPI pins. Default allows Uno shields to be used on other * boards. */ // define software SPI pins /** Default Software SPI chip select pin */ uint8_t const SOFT_SPI_CS_PIN = 10; /** Software SPI Master Out Slave In pin */ uint8_t const SOFT_SPI_MOSI_PIN = 11; /** Software SPI Master In Slave Out pin */ uint8_t const SOFT_SPI_MISO_PIN = 12; /** Software SPI Clock pin */ uint8_t const SOFT_SPI_SCK_PIN = 13;