void SPI_init_master(void)			// Initialisieren als Master
	{	
	DDRB = (1<<DDB3)|(1<<DDB5);  		// ...
	SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR1);	// Master, SCK=fosc/64 = 250 kHz
	}			

void SPI_transmit_master (int transmit_data)
	{
	PORTB &= ~(1<<PB1);
	SPDR = transmit_data;
	while (!(SPSR & (1<<SPIF)));
	PORTB |= (1<<PB1);
	}

int main(void)

{
wait(10000);

sei();	
USART_init(2400);
DDRB=0b01111111; 			//Pin B0 als Eingang
PORTB=0x7f;


SPI_init_master();
SPI_transmit_master(0x20);  	// Channel Ain1+ Ain1- ; Enter Clock Register
SPI_transmit_master(0x0e);  	// Master Clock Enabled; 4,43 MHz clock,CLKDIV = 1 -> intern mit 4,43 / 2 MHz ; Output Rate 250 Hz; 
SPI_transmit_master(0x10);	// Setup Register + Same Channel wie oben
SPI_transmit_master(0x00);	// gain = 1, bipolar mode, buffer off, clear FSYNC und normal mode

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}