#include "spi.h"
#include <avr/io.h>

uint8_t spi_init(uint8_t spcr) {
  PORTB |= (1 << 5); // set SCK hi
  DDRB |= (1 << 5); // set SCK as output
  DDRB &= ~(1 << 4); // set MISO as input
  DDRB |= (1 << 3); // set MOSI as output
  DDRB |= (1 << 2); // SS must be output for Master mode to work

  SPCR = spcr | SPE;
  return(SPSR);
}

uint8_t spi_transfer(uint8_t in) {
  uint8_t v;
  SPDR = in;
  // wait for transfer to complete
  while(! (SPSR & (1<<SPIF)) ) {};
  v = SPDR;
  return(v);
}