Initializes the device SPI peripheral in master or slave mode.
Note: MISO, MOSI and SCK idle in high-impedance state when SPI peripheral is configured in slave mode and the device is not selected.
ss_pin: slave-select pin to initialize. The default SS pin varies by port and device, see above.
// Example using SPI in master mode, with the default SS pin: SPI.begin(SPI_MODE_MASTER); // Example using SPI1 in slave mode, with D5 as the SS pin SPI1.begin(SPI_MODE_SLAVE, D5); // Example using SPI2 in slave mode, with C0 as the SS pin // (Electron and E Series only) SPI2.begin(SPI_MODE_SLAVE, C0);
On Gen 3 devices (Argon, Boron, and Xenon), SPI slave can only be used on SPI1. It is not supported on SPI. The maximum speed is 8 MHz on SPI1.