#define SPI_BAUDRATE 1000000
#define SPI_MASTER 1
#define SPI_READBUF_LEN 32
#define SPI_SS_PORT D
#define SPI_SS_PIN 7



// copied/adapted from usbdrv.h
#define SPI_CONCAT(a, b)            a ## b

#define SPI_OUTPORT(name)           SPI_CONCAT(PORT, name)
#define SPI_INPORT(name)            SPI_CONCAT(PIN, name)
#define SPI_DDRPORT(name)           SPI_CONCAT(DDR, name)

#define SPI_SSOUT SPI_OUTPORT(SPI_SS_PORT)
#define SPI_SSIN SPI_INPORT(SPI_SS_PORT)
#define SPI_SSDDR SPI_DDRPORT(SPI_SS_PORT)

uint8_t spi_write(uint8_t *data, uint8_t len);
void spi_init();