xyFC/include/avr/spi.h

/*
 * Bit-Banged SPI routines
 */

#ifndef _AVR_SPI_H
#define _AVR_SPI_H

#include <avr/io.h>

#ifdef DEBUG

// Arduino D3 = PD3
#define SCK_on PORTD |= (1 << PD3)
#define SCK_off PORTD &= ~(1 << PD3)
#define SCK_dir DDRD |= (1 << PD3)

// Arduino D7 = PD7
#define MO_on PORTD |= (1 << PD7)
#define MO_off PORTD &= ~(1 << PD7)
#define MO_dir DDRD |= (1 << PD7)

// Arduino D8 = PB0
#define CS_on PORTB |= (1 << PB0)
#define CS_off PORTB &= ~(1 << PB0)
#define CS_dir DDRB |= (1 << PB0)

// Arduino D2 = PD2
#define MI_1 (PIND & (1 << PD2)) != 0
#define MI_0 (PIND & (1 << PD2)) == 0
#define MI_dir DDRD &= ~(1 << PD2); PORTD |= (1 << PD2)

// Arduino D9 = PB1
#define GDO_1 (PINB & (1 << PB1)) != 0
#define GDO_0 (PINB & (1 << PB1)) == 0
#define GDO_dir DDRB &= ~(1 << PB1); PORTB |= (1 << PB1)

#else

#define SCK_on PORTB |= (1 << PB4)
#define SCK_off PORTB &= ~(1 << PB4)
#define SCK_dir DDRB |= (1 << PB4)

#define MO_on PORTB |= (1 << PB2)
#define MO_off PORTB &= ~(1 << PB2)
#define MO_dir DDRB |= (1 << PB2)

#define CS_on PORTB |= (1 << PB1)
#define CS_off PORTB &= ~(1 << PB1)
#define CS_dir DDRB |= (1 << PB1)

#define MI_1 (PINB & (1 << PB3)) != 0
#define MI_0 (PINB & (1 << PB3)) == 0
#define MI_dir DDRB &= ~(1 << PB3); PORTB |= (1 << PB3)

#define GDO_1 (PINB & (1 << PB0)) != 0
#define GDO_0 (PINB & (1 << PB0)) == 0
#define GDO_dir DDRB &= ~(1 << PB0); PORTB |= (1 << PB0)

#endif

#define NOP() __asm__ __volatile__("nop")

#endif