PIC und 22 Bit AD Wandler ueber SPI, kriege es nicht gebacken

#include <pic.h>

__CONFIG(INTIO & WDTDIS & PWRTEN & MCLRDIS & UNPROTECT \

  & UNPROTECT & BORDIS & IESODIS & FCMDIS);

// Variables

long int whatIwant;

#define FOSC 8000000L      // Internal Oscillator to 8Mhz

#define CS RA4          // AD Converter Pin

#define SDI RB4          // AD Converter Pin

#define SCK RB6          // AD Converter Pin

// Read AD Converter Function

long int Read3551(void)

{ 

  short i;

  long int result=0;

  char byte[3], TrashByte;      // Temp Bytes for reading

  CS=0;                         // AD Chip Select low to read

  while (SDI==1);                // Wait for SDO/RDY to become low (AD internal conversion complete)

  for (i=0; i<3; i++)          // Loop for reading Byte 1, 2 and 3

  {

    SSPBUF=0b00001111;          // Garbage send to start clocking in AD Data Byte 3

    while (BF==0);            // Wait for Buffer Full Status Bit to be set 

    byte[i]=SSPBUF;              // get byte

  }

  if (byte[2] < 32)            // Last 3 Bits must be zero (no overflow and no negative sign)

   result = ((byte[0] * 65536) + (byte[1] * 256) + (byte[2] * 1));    //Add the Bytes to get the whole Value

  CS=1;                    // AD Chip select high to stop AD sending

  return result;              // return the Value

}  

main()                // ------- MAIN -------

{

// declaration

  OSCCON = 0x75;        // Oscillator to 8 Mhz

  ANSEL = 0;                  // Turn off ADC

  TRISB6= 0;          // SCK (AD) is Output (Master Mode)

  TRISA4= 0;          // RA4 (CS from AD) is Output

  CS=1;            // CS high (AD stops sending)

  SSPCON= 0b00110000;      // 00, Enable SPI (SSPEN) , Idle State for SDI clock is high level (CKP), Fosc:4 

  SMP= 0;            // SPI Input Data sampled at middle of data output time

  CKE= 0;            // SDI Data transmitted on rising Edge of SCK

// Infinite loop with main program

for (;;)                     

 whatIwant=Read3551();

}                      //  End of MAIN