ATmega88 @ 1MHz SPI-Master - Datenübertragung zweier 8-Bit Daten (11010010 und 10000001)

spi-master-datenuebertragung.c

/*
* spi_send_01.c
* SPI-Master - Datenübertragung
* Übertragung zweier 8-Bit Daten (11010010 und 10000001)
* Controller: ATmega88 @ 1MHz
*/
#include <avr/io.h>
#include <util/delay.h>
 
void SPI_Master_Init(void)
{
    SPCR &= ~(1<<DORD);       // Send MSB first
    SPCR |= (1<<MSTR);        // Controller = Master
    SPCR &= ~(1<<CPOL);       // CLK positiv phase
    SPCR |= (1<<CPHA);        // Sampling data @ rising edge
    SPCR |= (1<<SPR1);        // CLK / 64 = 125kHz
    DDRB |= (1<<PB3);     // Set MOSI output
    DDRB &= ~(1<<PB4);        // Set MISO input
    DDRB |= (1<<PB5);     // Set SCK output
    DDRB |= (1<<PB2);     // Set SS output
    SPCR |= (1<<SPE);     // SPI enable
}
 
void SPI_Master_Transmit(char cData)
{
    PORTB &= ~(1<<PB2);               // SS = low (Slave = enabled)
    SPDR = cData;                   // Start transmission
    while (!(SPSR & (1<<SPIF)));  // Wait for transmission complete
    PORTB |= (1<<PB2);                // SS = high (Slave = disabled)
}
 
int main(void)
{
    SPI_Master_Init();
     
    while(1)
    {
        SPI_Master_Transmit(0b11010010);
        _delay_ms(500);     // delaytime between next transmission
        SPI_Master_Transmit(0b10000001);
        _delay_ms(500);     // delaytime between next transmission
    }
}