// code for SPI Master device
// Jurgen Strydom 2007 09 04
// www.flatspike.com

#include <p18f1220.h>
#include <delays.h>

#pragma config WDT = OFF, OSC = INTIO2, LVP = OFF, MCLRE = OFF

#define SW_DIN_PIN PORTAbits.RA0     // Data in
#define TRIS_SW_DIN_PIN TRISAbits.TRISA0
#define SW_DOUT_PIN PORTAbits.RA1    // Data out
#define TRIS_SW_DOUT_PIN TRISAbits.TRISA1
#define SW_SCK_PIN PORTBbits.RB2     // Clock
#define TRIS_SW_SCK_PIN TRISAbits.TRISA2
#define SW_CS_PIN PORTBbits.RB3 // Chip Select
#define TRIS_SW_CS_PIN TRISAbits.TRISA3

unsigned char b, Din, Dout;

void main (void);
void SPI_master_char (void);

//----------------------------------------------------------------------------
void main (void)
{
// OSC settings
  OSCCONbits.IRCF2 = 1; //Set osc to be 8 MHZ
  OSCCONbits.IRCF1 = 1;	//OSCCON<2:0> = 111;
  OSCCONbits.IRCF0 = 1;	//
// other stuff
  ADCON1 = 0b11111111;
// SPI settings
  TRISA = 0;
  PORTA = 0;
  TRISB = 0;
  PORTB = 0;
  TRIS_SW_DIN_PIN = 1; // Data in   
  TRIS_SW_DOUT_PIN = 0;// Data out
  TRIS_SW_SCK_PIN = 0;// Clock
  TRIS_SW_CS_PIN = 0;// Chip Select	
  
  PORTBbits.RB1 = 1;
  Delay10KTCYx(200);
  PORTBbits.RB1 = 0;
  while(1) {
	Delay10KTCYx(50);
	Dout = 170;
	SPI_master_char();
  }
}

//----------------------------------------------------------------------------
// SPI stuff
/* SW_DIN_PIN    // Data in
   SW_DOUT_PIN   // Data out
   SW_SCK_PIN    // Clock
   SW_CS_PIN     // Chip Select */
void SPI_master_char(void)
{
	SW_SCK_PIN = 0;
    SW_CS_PIN = 1;
    Delay10TCYx(10);
	b = 8;
	for (b = 8; b >0 ; b--) {
	    Rlcf(Dout,1,1);
	    SW_DOUT_PIN = STATUSbits.C;
		SW_SCK_PIN = 1;
		Delay10TCYx(10);
	    STATUSbits.C = SW_DIN_PIN;
	    Rlcf(Din,1,1);
		SW_SCK_PIN = 0;
		Delay10TCYx(10);
 	}
    SW_CS_PIN = 0;
}