#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <stdio.h>
//#include "uart.h"

//FILE uart_str = FDEV_SETUP_STREAM(uart_putchar, uart_getchar, _FDEV_SETUP_RW);

char transmit_flag;
char local_status;
char remote_status;

void SPIInit();
char txSPI(char data);
char rxSPI();

#define switches()	~PINA
#define setLEDs(x)	PORTD = x

int main()
{
	SPIInit();

	while(1){
		// Read in the local switches, for transmission.
		local_status = switches();
		remote_status = txSPI(0x00);
		setLEDs(~remote_status);

	//	fprintf(stdout,"Remote: 0x%0X \n\r", remote_status);
		_delay_ms(10);		
	}
}

   
void SPIInit()  
{  
	// Initialize the UART
// 	uart_init(); stdout = &uart_str;
//	_delay_us(100);
//	fprintf(stdout,"Starting SPI test: MASTER");
	
	// make the MOS20I, SCK, and SS pins outputs  
    DDRB |= (1<<PB5) | (1<<PB7) | (1<<PB4);  
  
    // make sure the MISO pin is input  
    DDRB &= ~(1<<PB6);

	// Set up switches as input, LEDs as output
	DDRA = 0x00; DDRD = 0xFF; //PORTC = 0xFF;
  
    // set up the SPI module: SPI enabled, MSB first, master mode,  
    //  clock polarity and phase = 0, F_osc/8  
    SPCR = (1<<SPE) | (1<<MSTR) | (1<<SPR0);  
    SPSR = 1;
  
    transmit_flag = 0;  
}

char txSPI(char data)
{
	PORTB &= 0xEF;   
	if (transmit_flag)
    	while (!(SPSR & (1<<SPIF)));            
    SPDR = data;
	while (!(SPSR & (1<<SPIF)));       
	PORTB |= 0x10;
	return SPDR;
}

char rxSPI()
{
	if(transmit_flag)
		while(!(SPSR & (1<<SPIF)));
	_delay_us(3);
	SPDR = 0x00;
	while(!(SPSR & (1<<SPIF)));
	transmit_flag = 0;
	return SPDR;
}