wireless coding for 18F4520 using nrf24l01

2011年3月21日 6:02
i have use this code but it doesnt work .
how do i change the crystal value to external christal.
/*
 ** test.c
 ** SPI test program for PIC18F4520 and nRF24L01 or nRF24L01+
 ** Checks SPI comms between PIC and wireless chip
 ** 
 ** RA0  LED (output)
 ** RA1  PB (input)
 */
 
 #include <p18f4520.h>
 #include <spi.h>
 
 //function prototypes
 unsigned char spi_Send_Read(unsigned char);
 
 // Defines
 #define SPI_SCK    LATCbits.LATC3    // Clock pin, PORTC pin 3 
 #define SPI_SO    LATCbits.LATC5    // Serial output pin, PORTC pin 5 
 #define SPI_SI    PORTCbits.RC4    // Serial input pin, PORTC pin 4 
 #define SPI_CSN    LATCbits.LATC2    // CSN output pin, PORTC pin 2
 #define SPI_CE    LATCbits.LATC1    // CE output pin, PORTC pin 1
 #define SPI_IRQ    PORTBbits.RB0    // IRQ input pin, PORTB pin 0
 #define SPI_SCALE  4           // postscaling of signal 
 #define LED      LATAbits.LATA0
 #define PB      PORTAbits.RA1
 
 
 // Macros
 #define nop() _asm nop _endasm
 
 void main(void)
 {
  unsigned char status = 0;
  unsigned char data[5];
  int i;
 
  // run internal oscillator at 8 MHz
  OSCCON = OSCCON | 0x34;
  while (OSCCONbits.IOFS == 0)
    ;
 
  OpenSPI(SPI_FOSC_16, MODE_00, SMPMID); //open SPI1
  PORTA = 0x00;
  ADCON1 = 0x0F;    // set up PORTA to be digital I/Os
  TRISA = 0x02;    // PORTA<7.2,0> outputs PORTA<1> input
  TRISCbits.TRISC3 = 0;  // SDO output
  TRISCbits.TRISC5 = 0;  // SCK output
  TRISCbits.TRISC2 = 0;  // CSN output
  TRISCbits.TRISC1 = 0;  // CE output
  SPI_CSN = 1;    // CSN high
  SPI_SCK = 0;    // SCK low
  SPI_CE  = 0;    // CE low
  nop();
 
  //write TX_ADDRESS register
  SPI_CSN = 0;      //CSN low
  spi_Send_Read(0x30);
  spi_Send_Read(0x11);
  spi_Send_Read(0x22);
  spi_Send_Read(0x33);
  spi_Send_Read(0x44);
  spi_Send_Read(0x55);
  SPI_CSN = 1;      //CSN high
 
 
  //read TX_ADDRESS register
  //Check that values are correct using the MPLAB debugger
  SPI_CSN = 0;      //CSN low
  status = spi_Send_Read(0x10);
  data[0] = spi_Send_Read(0x00);  // 0x11
  data[1] = spi_Send_Read(0x00);  // 0x22
  data[2] = spi_Send_Read(0x00);  // 0x33
  data[3] = spi_Send_Read(0x00);  // 0x44
  data[4] = spi_Send_Read(0x00);  // 0x55
  SPI_CSN = 1;      //CSN high
 
  // test PB and LED
  while(1)
  {
    if (!PB)
      LED = 1;
    else
      LED = 0;
  }
 }
 
 
 unsigned char spi_Send_Read(unsigned char byte)
 {
  SSPBUF = byte;  
  while(!DataRdySPI())
    ;  
  return SSPBUF;
 }