The SPI (SCK, MOSI, MISO) pins on e.g. an 328P (Uno, Nano, ProMini) / 2560 (Mega) are fixed by the processor's hardware; there is no need to define them.
Other processors have options to route the internal SPI hardware to different pins.
The SPI (SCK, MOSI, MISO) pins on e.g. an 328P (Uno, Nano, ProMini) / 2560 (Mega) are fixed by the processor's hardware; there is no need to define them.
Other processors have options to route the internal SPI hardware to different pins.