nmea.c

//
//    This file is part of Dire Wolf, an amateur radio packet TNC.
//
//    Copyright (C) 2014, 2015  John Langner, WB2OSZ
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 2 of the License, or
//    (at your option) any later version.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with this program.  If not, see <http://www.gnu.org/licenses/>.
//


//#define DEBUG 1


// TODO: rename this to waypoint & integrate.

/*------------------------------------------------------------------
 *
 * Module:      nmea.c
 *
 * Purpose:   	Receive NMEA sentences from a GPS receiver.
 *		Send NMEA waypoint sentences to GPS display or mapping application.
 *		
 *---------------------------------------------------------------*/

#include <stdio.h>
#include <unistd.h>

#if __WIN32__
#include <stdlib.h>
#include <windows.h>
#else
#define __USE_XOPEN2KXSI 1
#define __USE_XOPEN 1
//#define __USE_POSIX 1
#include <stdlib.h>
#include <ctype.h>
#include <fcntl.h>
#include <termios.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#endif

#include <assert.h>
#include <string.h>

#if __WIN32__
char *strsep(char **stringp, const char *delim);
#endif

#include "direwolf.h"
#include "config.h"
#include "ax25_pad.h"
#include "textcolor.h"
//#include "xmit.h"
#include "latlong.h"
#include "nmea.h"
#include "grm_sym.h"		/* Garmin symbols */
#include "mgn_icon.h"		/* Magellan icons */
#include "serial_port.h"


// TODO: receive buffer... static kiss_frame_t kf;	/* Accumulated KISS frame and state of decoder. */

static MYFDTYPE nmea_port_fd = MYFDERROR;

static void nmea_send_sentence (char *sent);



//static void nmea_parse_gps (char *sentence);


static int nmea_debug = 0;		/* Print information flowing from and to attached device. */

void nmea_set_debug (int n) 
{	
	nmea_debug = n;
}


/*-------------------------------------------------------------------
 *
 * Name:	nmea_init
 *
 * Purpose:	Initialization for NMEA communication port.
 *
 * Inputs:	mc->nmea_port	- name of serial port.
 *
 * Global output: nmea_port_fd
 *	
 *
 * Description:	(1) Open serial port device.
 *
 *---------------------------------------------------------------*/


void nmea_init (struct misc_config_s *mc)
{
	
/*
 * Open serial port connection.
 * 4800 baud is standard for GPS.
 * Should add an option to allow changing someday.
 */
	if (strlen(mc->nmea_port) > 0) {

	  nmea_port_fd = serial_port_open (mc->nmea_port, 4800);


	}


#if DEBUG
	text_color_set (DW_COLOR_DEBUG);

	dw_printf ("end of nmea_init: nmea_port_fd = %d\n", nmea_port_fd);
#endif
}



/*-------------------------------------------------------------------
 *
 * Name:        append_checksum
 *
 * Purpose:     Append checksum to the sentence.
 *		
 * In/out:	sentence	- NMEA sentence beginning with '$'.
 *
 * Description:	Checksum is exclusive of characters except leading '$'.
 *		We append '*' and an upper case two hexadecimal value.
 *
 *--------------------------------------------------------------------*/

static void append_checksum (char *sentence)
{
	char *p;
	int cs;

	assert (sentence[0] == '$');

	cs = 0;
	for (p = sentence+1; *p != '\0'; p++) {
	  cs ^= *p;
	}

	sprintf (p, "*%02X", cs & 0xff);

// Add crlf too?

} /* end append_checksum */



/*-------------------------------------------------------------------
 *
 * Name:        nema_send_waypoint
 *
 * Purpose:     Convert APRS position or object into NMEA waypoint sentence
 *		for use by a GPS display or other mapping application.
 *		
 * Inputs:	wname_in	- Name of waypoint.
 *		dlat		- Latitude.
 *		dlong		- Longitude.
 *		symtab		- Symbol table or overlay character.
 *		symbol		- Symbol code.
 *		alt		- Altitude in meters or G_UNKOWN.
 *		course		- Course in degrees or ??? for unknown.
 *		speed		- Speed in knots ?? or ??
 *		comment		- Description or message.
 *		
 *
 * Description:	Currently we send multiple styles.  Maybe someday there might
 * 		be an option to send a selected subset.
 *
 *			$GPWPL		- Generic with only location and name.
 *			$PGRMW		- Garmin, adds altitude, symbol, and comment
 *					  to previously named waypoint.
 *			$PMGNWPL	- Magellan, more complete for stationary objects.
 *			$PKWDWPL	- Kenwood with APRS style symbol but missing comment.
 * 
 *--------------------------------------------------------------------*/


void nmea_send_waypoint (char *wname_in, double dlat, double dlong, char symtab, char symbol, 
			float alt, float course, float speed, char *comment)
{
	char wname[12];		/* Waypoint name.  Any , or * removed. */
	char slat[12];		/* DDMM.mmmm */
	char slat_ns[2];	/* N or S */
	char slong[12];		/* DDDMM.mmmm */
	char slong_ew[2];	/* E or W */	
	char sentence[500];
	char salt[12];		/* altitude as string, empty if unknown */
	char sspeed[12];	/* speed as string, empty if unknown */
	char scourse[12];	/* course as string, empty if unknown */
	int grm_sym;		/* Garmin symbol code. */
	char sicon[5];		/* Magellan icon string */
	char stime[8];
	char sdate[8];
	char *p;



// Remove any comma from name.

// TODO: remove any , or * from comment.

	strcpy (wname, wname_in);
	for (p=wname; *p != '\0'; p++) {
	  if (*p == ',') *p = ' ';
	  if (*p == '*') *p = ' ';
	}

// Convert position to character form.

	latitude_to_nmea (dlat, slat, slat_ns);
	longitude_to_nmea (dlong, slong, slong_ew);

/*
 *	Generic.
 *
 *	$GPWPL,ddmm.mmmm,ns,dddmm.mmmm,ew,wname*99
 *
 *	Where,
 *	 	ddmm.mmmm,ns	is latitude
 *		dddmm.mmmm,ew	is longitude
 *		wname		is the waypoint name
 *		*99		is checksum
 */

	snprintf (sentence, sizeof(sentence), "$GPWPL,%s,%s,%s,%s,%s", slat, slat_ns, slong, slong_ew, wname);
	append_checksum (sentence);
	nmea_send_sentence (sentence);



/*
 *	Garmin - https://www8.garmin.com/support/pdf/NMEA_0183.pdf
 *		 http://gpsinformation.net/mag-proto.htm
 *
 *	$PGRMW,wname,alt,symbol,comment*99
 *
 *	Where,
 *
 *		wname		is waypoint name.  Must match existing waypoint.
 *		alt		is altitude in meters.
 *		symbol		is symbol code.  Hexadecimal up to FFFF.
 *				    See Garmin Device Interface Specification 001-0063-00.
 *		comment		is comment for the waypoint.  
 *		*99		is checksum
 */

	if (alt == G_UNKNOWN) {
	  strcpy (salt, "");
	} 
	else {
	  snprintf (salt, sizeof(salt), "%.1f", alt);
	}
	grm_sym = 0x1234; 	// TODO

	snprintf (sentence, sizeof(sentence), "$PGRMW,%s,%s,%04X,%s", wname, salt, grm_sym, comment);
	append_checksum (sentence);
	nmea_send_sentence (sentence);

/*
 *	Magellan - http://www.gpsinformation.org/mag-proto-2-11.pdf
 *
 *	$PMGNWPL,ddmm.mmmm,ns,dddmm.mmmm,ew,alt,unit,wname,comment,icon,xx*99
 *
 *	Where,
 *	 	ddmm.mmmm,ns	is latitude
 *		dddmm.mmmm,ew	is longitude
 *		alt		is altitude
 *		unit		is M for meters or F for feet
 *		wname		is the waypoint name
 *		comment		is message or comment
 *		icon		is one or two letters for icon code
 *		xx		is waypoint type which is optional, not well 
 *					defined, and not used in their example.					
 *		*99		is checksum
 */

// TODO: icon

	snprintf (sicon, sizeof(sicon), "??");
	snprintf (sentence, sizeof(sentence), "$PMGNWPL,%s,%s,%s,%s,%s,M,%s,%s,%s",
			slat, slat_ns, slong, slong_ew, salt, wname, comment, sicon);
	append_checksum (sentence);
	nmea_send_sentence (sentence);

/*
 *	Kenwood - Speculation due to no official spec found so far.
 *
 *	$PKWDWPL,hhmmss,v,ddmm.mmmm,ns,dddmm.mmmm,ew,speed,course,ddmmyy,alt,wname,ts*99
 *
 *	Where,
 *		hhmmss		is time in UTC.  Should we supply current
 *					time or only pass along time from
 *					received signal?
 *		v		indicates valid data ?????????????????
 *					Why would we send if not valid?
 *	 	ddmm.mmmm,ns	is latitude
 *		dddmm.mmmm,ew	is longitude
 *		speed		is speed in UNITS ???  knots ?????
 *		course		is course in degrees
 *		ddmmyy		is date.  Same question as time.
 *		alt		is altitude.  in UNITS ??? meters ???
 *		wname		is the waypoint name
 *		ts		are the table and symbol.
 *					Non-standard parsing would be required
 *					to deal with these for symbol:
 *						, Boy Scouts / Girl Scouts
 *						* SnowMobile / Snow				
 *		*99		is checksum
 *
 *	Oddly, there is not place for comment.
 */
 
	if (speed == G_UNKNOWN) {
	  strcpy (sspeed, "");
	} 
	else {
	  snprintf (sspeed, sizeof(sspeed), "%.1f", speed);
	}
	if (course == G_UNKNOWN) {
	  strcpy (scourse, "");
	} 
	else {
	  snprintf (scourse, sizeof(scourse), "%.1f", course);
	}

// TODO:  how to handle time & date ???

	strcpy (stime, "123456");
	strcpy (sdate, "123456");

	snprintf (sentence, sizeof(sentence), "$PKWDWPL,%s,V,%s,%s,%s,%s,%s,%s,%s,%s,%s,%c%c",
			stime, slat, slat_ns, slong, slong_ew, 
			sspeed, scourse, sdate, salt, wname, symtab, symbol);
	append_checksum (sentence);
	nmea_send_sentence (sentence);

/*
 *	One application recognizes these.  Not implemented at this time.
 *
 *	$GPTLL,01,ddmm.mmmm,ns,dddmm.mmmm,ew,tname,000000.00,T,R*99
 * 
 *	Where,
 *		ddmm.mmmm,ns	is latitude
 *		dddmm.mmmm,ew	is longitude
 *		tname		is the target name
 *		000000.00	is timestamp ???
 *		T		is target status (S for need help)
 *		R		is reference target ???
 *		*99		is checksum
 * 
 * 
 *	$GPTXT,01,01,tname,message*99
 *
 *	Where,
 *
 *		01		is total number of messages in transmission
 *		01		is message number in this transmission
 *		tname		is target name.  Should match name in WPL or TTL.
 *		message		is the message.  
 *		*99		is checksum
 * 
 */

} /* end nmea_send_waypoint */


#if 0

*  d710a menu 603   $GPWPL  $PMGNWPL  $PKWDWPL

symbol mapping

https://freepository.com:444/50lItuLQ7fW6s-web/browser/Tracker2/trunk/sources/waypoint.c?rev=108



Data Transmission Protocol For Magellan Products - version 2.11






$PMGNWPL,4651.529,N,07111.425,W,0000000,M,GC5A5F, GC. The straight line,a*13
 $PMGNWPL,3549.499,N,08650.827,W,0000257,M,HOME,HOME,c*4D

http://gpsbabel.sourcearchive.com/documentation/1.3.7~cvs1/magproto_8c-source.html

      sscanf(trkmsg,"$PMGNWPL,%lf,%c,%lf,%c,%d,%c,%[^,],%[^,]", 
            &latdeg,&latdir,
            &lngdeg,&lngdir,
            &alt,&altunits,shortname,descr);  then icon

   snprintf(obuf, sizeof(), "PMGNWPL,%4.3f,%c,%09.3f,%c,%07.0f,M,%-.*s,%-.46s,%s",
            lat, ilat < 0 ? 'S' : 'N',
            lon, ilon < 0 ? 'W' : 'E',
            waypointp->altitude == unknown_alt ?
                  0 : waypointp->altitude,
            wpt_len,
            owpt,
            odesc,
            icon_token);

https://freepository.com:444/50lItuLQ7fW6s-web/changeset/108/Tracker2/trunk/sources/waypoint.c

$PMGNWPL,4106.003,S,14640.214,E,0000069,M,KISSING SPOT,,a*3C





 *
https://freepository.com:444/50lItuLQ7fW6s-web/changeset/325


#endif


static void nmea_send_sentence (char *sent)
{

	int err;
	int len = strlen(sent);


	if (nmea_port_fd == MYFDERROR) {
	  return;
	}

	text_color_set(DW_COLOR_XMIT);
	dw_printf ("%s\n", sent);

	if (nmea_debug) {
	  // TODO: debugg out... nmea_debug_print (TO_CLIENT, NULL, nmea_buff+1, nmea_len-2);
	}

// TODO:  need to append CR LF.

	serial_port_write (nmea_port_fd, sent, len);

} /* nmea_send_sentence */





/* end nmea.c */