gcode_parse.h

#ifndef	_GCODE_PARSE_H
#define	_GCODE_PARSE_H

#include	<stdint.h>

#include	"dda.h"
#include "sd.h"

// whether to insist on N line numbers
// if not defined, N's are completely ignored
//#define	REQUIRE_LINENUMBER

// whether to insist on a checksum
//#define	REQUIRE_CHECKSUM

/// this is a very crude decimal-based floating point structure.
/// a real floating point would at least have signed exponent.\n
/// resulting value is \f$ mantissa * 10^{-(exponent - 1)} * ((sign * 2) - 1)\f$
typedef struct {
	uint32_t	mantissa;		///< the actual digits of our floating point number
	uint8_t	exponent	:7;	///< scale mantissa by \f$10^{-exponent}\f$
	uint8_t	sign			:1; ///< positive or negative?
} decfloat;

/// this holds all the possible data from a received command
typedef struct {
	struct {
		uint8_t					seen_G	:1;
		uint8_t					seen_M	:1;
		uint8_t					seen_X	:1;
		uint8_t					seen_Y	:1;
		uint8_t					seen_Z	:1;
		uint8_t					seen_E	:1;
		uint8_t					seen_F	:1;
		uint8_t					seen_S	:1;
		uint8_t					seen_P	:1;
		uint8_t					seen_T	:1;
		uint8_t					seen_N	:1;
		uint8_t					seen_checksum				:1; ///< seen a checksum?
		uint8_t					seen_semi_comment		:1; ///< seen a semicolon?
		uint8_t					seen_parens_comment	:1; ///< seen an open parenthesis
    uint8_t         read_string         :1; ///< Currently reading a string.
		uint8_t					option_all_relative	:1; ///< relative or absolute coordinates?
		uint8_t					option_e_relative		:1; ///< same for e axis (M82/M83)
		uint8_t					option_inches				:1; ///< inches or millimeters?
	};

  uint32_t          N;          ///< line number
  uint32_t          N_expected; ///< expected line number

  int32_t           S;          ///< S word (various uses)
  uint16_t          P;          ///< P word (various uses)

	uint8_t						G;				///< G command number
	uint8_t						M;				///< M command number
	TARGET						target;		///< target position: X, Y, Z, E and F

	uint8_t						T;				///< T word (tool index)

	uint8_t						checksum_read;				///< checksum in gcode command
	uint8_t						checksum_calculated;	///< checksum we calculated
} GCODE_COMMAND;

enum gcode_source {
  GCODE_SOURCE_SERIAL  = 0b00000001,
  GCODE_SOURCE_SD      = 0b00000010,
};


extern enum gcode_source gcode_sources;
extern enum gcode_source gcode_active;

/// the command being processed
extern GCODE_COMMAND next_target;

#ifdef SD
  /// For storing incoming strings. Currently the only use is SD card filename.
  extern char gcode_str_buf[];
#endif

void gcode_init(void);

/// accept the next character and process it
uint8_t gcode_parse_char(uint8_t c);

// uses the global variable next_target.N
void request_resend(void);

#endif	/* _GCODE_PARSE_H */