RFM12B per SPI Schnittstelle - Problem mit dem Empfänger

[H. G. (ledi)]

Hallo!

Ich möchte ein Testbyte vom RFM12-Sender an den RFM12-Empfänger senden 
und das gesendete Byte am PORTC (8x LEDs) anzeigen.
Der Sender dürfte auch senden (mit dem Oszi an der Antenne lässt sich 
ein rythmisches Signal messen).
Am Empfänger habe ich einen AT90PWM316 mit dem RFM12B per 
SPI-Schnittstelle verbunden.
Und hier habe ich offensichtlich irgendwo einen Fehler.

Anbei der C-Code:

/************************************************************
* 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
    }
}