#ifndef	_INTERCOM_H
#define	_INTERCOM_H

#include	<stdint.h>
#include	"config.h"

#ifdef HOST
	#define enable_transmit()			do { WRITE(TX_ENABLE_PIN,1);  UCSR1B &=~MASK(RXEN1); } while(0)
	#define disable_transmit()			do { WRITE(TX_ENABLE_PIN,0);  UCSR1B &= ~(MASK(TXCIE1) | MASK(UDRIE1)); UCSR1B |= MASK(RXEN1); } while(0)
#else
	#define enable_transmit()			do { WRITE(TX_ENABLE_PIN,1);  UCSR0B &= ~MASK(RXEN0); } while(0)
	#define disable_transmit()			do { WRITE(TX_ENABLE_PIN,0);  UCSR0B &= ~(MASK(TXCIE0) | MASK(UDRIE0)); UCSR0B |= MASK(RXEN0); } while(0)
#endif

enum {
	ERROR_BAD_CRC
} err_codes;

typedef struct {
	uint8_t		start;
	uint8_t		dio;
	uint8_t		controller_num;
	uint8_t		control_word;
	uint8_t		control_index;
	union {
		int32_t		control_data_int32;
		uint32_t	control_data_uint32;
		float			control_data_float;
		uint16_t	temp[2];
	};
	uint8_t		err;
	uint8_t		crc;
} intercom_packet_t;

typedef union {
	intercom_packet_t packet;
	uint8_t						data[sizeof(intercom_packet_t)];
} intercom_packet;

extern intercom_packet tx;
extern intercom_packet rx;

// initialise serial subsystem
void intercom_init(void);

// if host, send target temperature to extruder
// if extruder, send actual temperature to host
void send_temperature(uint8_t index, uint16_t temperature);

// if host, read actual temperature from extruder
// if extruder, read target temperature from host
uint16_t read_temperature(uint8_t index);

// if host, set DIOs on extruder controller
// if extruder, report DIO state
void set_dio(uint8_t index, uint8_t value);

// if host, read extruder DIO inputs
// if extruder, set DIO outputs
uint8_t	get_dio(uint8_t index);

// set error code to send to other end
void set_err(uint8_t err);

// get error code sent from other end
uint8_t get_err(void);

// if host, send packet to extruder
// if extruder, return packet to host
void start_send(void);

#define	FLAG_RX_IN_PROGRESS	1
#define	FLAG_TX_IN_PROGRESS	2
#define FLAG_NEW_RX					4
#define	FLAG_TX_FINISHED		8
extern volatile uint8_t	intercom_flags;



#endif	/* _INTERCOM_H */