b15f/firmware/spi.h

#ifndef SPI_H
#define SPI_H

#include <util/delay.h>
#include <avr/io.h>
#include <stdint.h>

#define SLSL PB4
#define MOSI PB5
#define MISO PB6
#define SCLK PB7

#define DMUX1 PD2
#define DMUX2 PD3
#define DMUX3 PD4

enum SPIADR {
	AA0    = 0,
	AA1    = 1,
	BEBA0  = 2,
	BEBA1  = 3,
	EXT    = 4,
	SWITCH = 5,
	NONE   = 7,
};

class SPI
{
public:
	SPI(void);
	void init(void) const volatile;
	void handleTransfer() volatile;	
	void transfer(uint8_t adr) volatile;
	void addByte(uint8_t b) volatile;
	void wait(void) volatile;
	
	constexpr static uint8_t BUFFER_SIZE = 8;
	volatile uint8_t buffer[BUFFER_SIZE];

private:
	void setAdr(uint8_t) const volatile;
	
	volatile uint8_t index = 0;
	volatile uint8_t length = 0;
	volatile bool active = false;
};

#endif // SPI_H