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38 lines
758 B
C

#include "spi.h"
void spi_select(void)
{
CS_PORT&=~(1<<CS_BIT);
}
void spi_deselect(void)
{
CS_PORT|=(1<<CS_BIT);
}
unsigned char spi_xchg(unsigned char val)
{
SPDR = val;
while (!(SPSR & (1 << SPIF))) ;
return SPDR;
}
uint8_t spi_read(){
return spi_xchg(0x00);
}
void spi_write(uint8_t d){
spi_xchg(d);
}
void spi_init(){
CS_PORT |= (1 << CS_BIT); // pull CS pin high
CS_DDR |= (1 << CS_BIT); // now make it an output
SPI_PORT |= (1 << 0); // make sure SS is high
SPI_DDR = (1 << PORTB2) | (1 << PORTB1) | (1 << PORTB0); // set MOSI, SCK and SS as output, others as input
SPCR = (1 << SPE) | (1 << MSTR); // enable SPI, master mode 0
SPCR |= (1 << SPR0) | (0<<SPR1); // div 128
SPSR |= (0 << SPI2X); // set the clock rate fck/2
}