RFM12B per SPI Schnittstelle - Problem mit dem Empfänger

/************************************************************

* RFM12B - Receiver                      *

* Controller:   AT90PWM316, 1MHz               *

************************************************************/

#include <avr/io.h>

#include <stdlib.h>

#include <util/delay.h>

#include "SPI.h"

#define write   0xB8

#define read   0xB0

void SPI_Master_Init(void)  // SPI Initialisierung

{  

  DDRB |=    (1<<PB1);  // Set MOSI output

  DDRB &=    ~(1<<PB0);  // Set MISO input

  DDRB |=    (1<<PB7);  // Set SCK output

  DDRD |=    (1<<PD3);  // Set CS output

  PORTD |=  (1<<PD3);  // Set CS = high

  DDRC |=   0xFF;    // PORTC = output

  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

  SPCR |=    (1<<SPE);  // SPI enable

  _delay_ms(500);      // Power-on-delay 500ms

}

void SPI_transfer(char data)

{

    SPDR = data;            // write to FIFO

  while (!(SPSR & (1<<SPIF)));

}

void Receive (char command, char data)

{

  PORTD  &=  ~(1<<PD3);            // CS = Low  

  SPDR = command;            // Command read FIFO

  while (!(SPSR & (1<<SPIF)));

  SPDR = data;            // Write dummybyte

  while (!(SPSR & (1<<SPIF)));

  PORTC = SPDR;            // Ausgabe 8 LEDs am PORTC

  PORTD  |=  (1<<PD3);            // CS = High

}

void rfm12_init(void)

{

  _delay_ms(100);          // wait until Power On Reset (POR) done

  PORTD  &=  ~(1<<PD3);          // CS = Low

  SPI_transfer(0x80);        // Configuration Setting Command

  SPI_transfer(0xE7);        // 868 MHz, 12pF, enable Tx + Rx

  SPI_transfer(0x82);        // Power Management Command

  SPI_transfer(0xD9);        // Enable: receiver, base band block, synthesizer, crystall oszillator. Disable: clock output of CLK pin   

  SPI_transfer(0xA6);        // Frequency Setting Command

  SPI_transfer(0x7C);        // Set Frequency to 868,3 MHz

  SPI_transfer(0xC6);        // Data Rate Command

  SPI_transfer(0x47);        // 2400 kBaud

  SPI_transfer(0x94);        // Receiver Control Commmand

  SPI_transfer(0xA4);

  SPI_transfer(0xC2);        // Data Filter Command

  SPI_transfer(0xAC);        

  SPI_transfer(0xCA);        // FIFO & Reset Mode Command

  SPI_transfer(0x81); 

  SPI_transfer(0xC4);        // AFC Command

  SPI_transfer(0x83);        

  SPI_transfer(0x98);        // Tx Configuration Control Command

  SPI_transfer(0x50);

  SPI_transfer(0xE0);        // Wake-up timer Command

  SPI_transfer(0x00);

  SPI_transfer(0xC8);        // Low Duty-Cycle Command

  SPI_transfer(0x00);

  SPI_transfer(0xC0);        // Low Battery Detector & Microcontroller Clock Divider Command

  SPI_transfer(0x00);

  PORTD  |=  (1<<PD3);          // CS = High

}

void receiver_init(void)

{

  PORTD  &=  ~(1<<PD3);          // CS = Low

  SPI_transfer(0x82);

  SPI_transfer(0xC8);        // Rx ON

  SPI_transfer(0xCA);

  SPI_transfer(0x83);        // enable FIFO

  PORTD  |=  (1<<PD3);          // CS = High

}

int main (void)

{

    SPI_Master_Init();

  rfm12_init();

  receiver_init();

    while(1)

    {

        Receive (read, 0x00);    // 0xB000

    }

}