begin()
Initializes the SPI bus by setting SCK, MOSI, and SS to outputs, pulling SCK and MOSI low, and SS high.
SPI.begin()
None
None
SPI.begin(sck, miso, mosi, ss)
sck:
custom SCK pin
miso:
custom MISO pin
mosi:
custom MOSI pin
ss:
custom SS pin
Error code
