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#include "spi.h"
void spi_init()
{
// setup SPI-Port
DDR_SPI = (1<<DD_MOSI) | (1<<DD_SS) | (1<<DD_SCK);
PORT_SPI |= (1<<DD_SS);
// SPI Control Register (SPCR)
// SPI Enable=1 | Data Order=LSB | SPI_Master=1 (!make SS stay HIGH!)
// SPCR |= (1<<SPE) | (1<<DORD) | (1<<MSTR) | (1<<CPOL) | (1<<CPHA) | (1<<SPR1) | (1<<SPR0);
// (1<<DORD) - would be LSB-mode (, but we need MSB-mode!)
SPCR = (1<<SPE) | (1<<MSTR); // (1<<SPR1) | (1<<SPR0)
spi_setspeed(SPICLK_DEFAULT);
// setup SPI options
/// SPSR &= ~(1<<SPI2X); // do not use SPI speed-doubler
}
void spi_setspeed(SPICLK speed)
{
if(speed < 4) // nominal clock speeds
{
SPSR &= ~(1<<SPI2X); // do not use SPI speed-doubler
SPCR |= speed;
}
else // use SPI2X
{
SPSR |= (1<<SPI2X); // use SPI speed-doubler
SPCR |= (speed - 0x4);
}
_delay_ms(2);
}
void spi_putc(unsigned char c)
{
/// uart_putc('>');
/// uart_putc(c);
/// uart_putc('\n');
SPDR = c;
loop_until_bit_is_set(SPSR, SPIF);
/// stdout_put_string(uart_putc, "- [done]\n");
}
unsigned char spi_getc()
{
SPDR = 0xFF; // init receive register with value
/* Wait for reception complete */
while(!(SPSR & (1<<SPIF)));
/* Return data register */
return SPDR;
/// unsigned char c = SPDR;
/// uart_putc('<');
/// uart_putc(c);
/// uart_putc('\n');
/// return c;
}
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