evermore.c

gpsd, a popular GPS daemon.

	session->gpsdata.hdop = (double)getub(buf2, 10)*0.1;
	session->gpsdata.vdop = (double)getub(buf2, 11)*0.1;
	session->gpsdata.tdop = (double)getub(buf2, 12)*0.1;
	switch (getub(buf2, 13)) {
	case 0:	/* no position fix */
	case 1:	/* manual calls this "1D navigation" */
	    session->gpsdata.status = STATUS_NO_FIX;
	    session->gpsdata.fix.mode = MODE_NO_FIX;
	    break;
	case 2:	/* 2D navigation */
	    session->gpsdata.status = STATUS_FIX;
	    session->gpsdata.fix.mode = MODE_2D;
	    break;
	case 3:	/* 3D navigation */
	    session->gpsdata.status = STATUS_FIX;
	    session->gpsdata.fix.mode = MODE_3D;
	    break;
	case 4:	/* 3D navigation with DGPS */
	    session->gpsdata.status = STATUS_DGPS_FIX;
	    session->gpsdata.fix.mode = MODE_3D;
	    break;
	}
	/* that's all the information in this packet */
	gpsd_report(LOG_PROG, "DDO 0x04: mode=%d, status=%d\n", 
		    session->gpsdata.fix.mode,
		    session->gpsdata.status);
	return TIME_SET | DOP_SET | MODE_SET | STATUS_SET;

    case 0x06:	/* Channel Status Output */
	session->gpsdata.fix.time = session->gpsdata.sentence_time
	    = gpstime_to_unix((int)getuw(buf2, 2), getul(buf2, 4)*0.01) - session->context->leap_seconds;
	session->gpsdata.satellites = (int)getub(buf2, 8);
	session->gpsdata.satellites_used = 0;
	memset(session->gpsdata.used, 0, sizeof(session->gpsdata.used));
	if (session->gpsdata.satellites > 12) {
		gpsd_report(LOG_WARN, "Warning: EverMore packet has information about %d satellites!\n",
				session->gpsdata.satellites);
	}
	if (session->gpsdata.satellites > EVERMORE_CHANNELS) session->gpsdata.satellites = EVERMORE_CHANNELS;
	satcnt = 0;
	for (i = 0; i < (size_t)session->gpsdata.satellites; i++) {
	    int prn;
	    // channel = getub(buf2, 7*i+7+2)
            prn = (int)getub(buf2, 7*i+7+3);
	    if (prn == 0) continue;  /* satellite record is not valid */
	    session->gpsdata.PRN[satcnt] = prn;
	    session->gpsdata.azimuth[satcnt] = (int)getuw(buf2, 7*i+7+4);
	    session->gpsdata.elevation[satcnt] = (int)getub(buf2, 7*i+7+6);
	    session->gpsdata.ss[satcnt] = (int)getub(buf2, 7*i+7+7);
	    /*
	     * Status bits at offset 8:
	     * bit0 = 1 satellite acquired
	     * bit1 = 1 code-tracking loop locked
	     * bit2 = 1 carrier-tracking loop locked
	     * bit3 = 1 data-bit synchronization done
	     * bit4 = 1 frame synchronization done
	     * bit5 = 1 ephemeris data collected
	     * bit6 = 1 used for position fix
	     */
	    if (getub(buf2, 7*i+7+8) & 0x40) {
		session->gpsdata.used[session->gpsdata.satellites_used++]=prn;
	    }

	    satcnt++;
		
	}
	session->gpsdata.satellites = (int)satcnt;
	/* that's all the information in this packet */
	gpsd_report(LOG_PROG, "CSO 0x04: %d satellites used\n", 
		    session->gpsdata.satellites_used);
	return TIME_SET | SATELLITE_SET | USED_SET;

    case 0x08:	/* Measurement Data Output */
	/* clock offset is a manufacturer diagnostic */
	/* (int)getuw(buf2, 8);  clock offset, 29000..29850 ?? */
	session->gpsdata.fix.time = session->gpsdata.sentence_time
	    = gpstime_to_unix((int)getuw(buf2, 2), getul(buf2, 4)*0.01) - session->context->leap_seconds;
	visible = getub(buf2, 10);
	/* FIXME: read full statellite status for each channel */
	/* we can get pseudo range (m), delta-range (m/s), doppler (Hz) and status for each channel */
	/* gpsd_report(LOG_PROG, "MDO 0x04: visible=%d\n", visible); */
	gpsd_report(LOG_PROG, "MDO 0x04:\n");
	return TIME_SET;
    
    case 0x20:	/* LogConfig Info, could be used as a probe for EverMore GPS */
	gpsd_report(LOG_IO, "LogConfig EverMore packet, length %d: %s\n", datalen, gpsd_hexdump(buf2, datalen));
	return ONLINE_SET;

    case 0x22:	/* LogData */
	gpsd_report(LOG_IO, "LogData EverMore packet, length %d: %s\n", datalen, gpsd_hexdump(buf2, datalen));
	return ONLINE_SET;

    case 0x38:	/* ACK */
	gpsd_report(LOG_PROG, "EverMore command %02X ACK\n", getub(buf2, 2));
	return ONLINE_SET;
    
    default:
	gpsd_report(LOG_WARN, "unknown EverMore packet id 0x%02x, length %d: %s\n", buf2[0], datalen, gpsd_hexdump(buf2, datalen));
	return 0;
    }
}
/*@ -charint @*/

static gps_mask_t evermore_parse_input(struct gps_device_t *session)
{
    gps_mask_t st;

    if (session->packet.type == EVERMORE_PACKET){
	st = evermore_parse(session, session->packet.outbuffer, session->packet.outbuflen);
	return st;
#ifdef NMEA_ENABLE
    } else if (session->packet.type == NMEA_PACKET) {
	st = nmea_parse((char *)session->packet.outbuffer, session);
	return st;
#endif /* NMEA_ENABLE */
    } else
	return 0;
}

static bool evermore_speed(struct gps_device_t *session, speed_t speed)
{
    /*@ -type @*/
    unsigned char tmp8;
    unsigned char msg[] = {
	    0x89,          /*  0: msg ID, Serial Port Configuration */
	    0x01,          /*  1: bit 0 cfg for main serial, bit 1 cfg for DGPS port */
	    0x00,          /*  2: baud rate for main serial; 4800(0), 9600(1), 19200(2), 38400(3) */
	    0x00,          /*  3: baud rate for DGPS serial port; 4800(0), 9600(1), etc */
    };
    gpsd_report(LOG_PROG, "evermore_speed(%d)\n", speed);
    switch (speed) {
	    case 4800:  tmp8 = 0; break;
	    case 9600:  tmp8 = 1; break;
	    case 19200: tmp8 = 2; break;
	    case 38400: tmp8 = 3; break;
	    default: return false;
    }
    msg[2] = tmp8;
    return evermore_write(session, msg, sizeof(msg));
    /*@ +type @*/
}

static bool evermore_protocol(struct gps_device_t *session, int protocol)
{
    /*@ +charint */
    unsigned char tmp8;
    unsigned char evrm_protocol_config[] = {
	    0x84,    /* 0: msg ID, Protocol Configuration */
	    0x00,    /* 1: mode; EverMore binary(0), NMEA(1) */
	    0x00,    /* 2: reserved */
	    0x00,    /* 3: reserved */
    };
    /*@ -charint */
    gpsd_report(LOG_PROG, "evermore_protocol(%d)\n", protocol);
    /*@i1@*/tmp8 = (protocol != 0) ? 1 : 0;   /* NMEA : binary */
    evrm_protocol_config[1] = tmp8;
    return evermore_write(session, evrm_protocol_config, sizeof(evrm_protocol_config));
}

static bool evermore_nmea_config(struct gps_device_t *session, int mode)
/* mode = 0 : EverMore default */
/* mode = 1 : gpsd best */
/* mode = 2 : EverMore search, activate PEMT101 message */
{
    unsigned char tmp8;
    /*@ +charint */
    unsigned char evrm_nmeaout_config[] = {
	    0x8e,	/*  0: msg ID, NMEA Message Control */
	    0xff,       /*  1: NMEA sentence bitmask, GGA(0), GLL(1), GSA(2), GSV(3), ... */
	    0x01,       /*  2: nmea checksum no(0), yes(1) */
	    1,          /*  3: GPGGA, interval 0-255s */
	    0,          /*  4: GPGLL, interval 0-255s */
	    1,          /*  5: GPGSA, interval 0-255s */
	    1,          /*  6: GPGSV, interval 0-255s */
	    1,          /*  7: GPRMC, interval 0-255s */
	    0,          /*  8: GPVTG, interval 0-255s */
	    0,          /*  9: PEMT,101, interval 0-255s */
	    0, 0, 0, 0, 0, 0, /* 10-15: reserved */
    };
    /*@ -charint */
    gpsd_report(LOG_PROG, "evermore_nmea_config(%d)\n", mode);
    /*@i1@*/tmp8 = (mode == 1) ? 5 : 1;   /* NMEA GPGSV, gpsd  */
    evrm_nmeaout_config[6] = tmp8;           /* GPGSV, 1s or 5s */
    /*@i1@*/tmp8 = (mode == 2) ? 1 : 0;   /* NMEA PEMT101 */
    evrm_nmeaout_config[9] = tmp8;           /* PEMT101, 1s or 0s */
    return evermore_write(session, evrm_nmeaout_config, sizeof(evrm_nmeaout_config));
}

static void evermore_mode(struct gps_device_t *session, int mode)
{
    gpsd_report(LOG_PROG, "evermore_mode(%d), %d\n", mode, session->back_to_nmea ? 1 : 0);
    if (mode == 0) {
        /* NMEA */
        (void) evermore_protocol(session, 1);
        session->gpsdata.driver_mode = 0;
        (void) evermore_nmea_config(session, 1); /* configure NMEA messages for gpsd */
    } else {
        /* binary */
        (void) evermore_protocol(session, 0);
        session->back_to_nmea = false;
        session->gpsdata.driver_mode = 1;
    }
}

#ifdef ALLOW_RECONFIGURE
static void evermore_configurator(struct gps_device_t *session, unsigned int seq)
{
    gpsd_report(LOG_PROG, "evermore_configurator(%d)\n", seq);
    (void) evermore_nmea_config(session, 1); /* configure NMEA messages for gpsd (GPGSV every 5s) */
    if (seq == 0) {
        if (session->packet.type == NMEA_PACKET) {
	    gpsd_report(LOG_WARN, "NMEA_PACKET packet\n");
        }
        (void) evermore_mode(session, 1); /* switch GPS to binary mode */
        session->back_to_nmea = true;
    }
}
#endif /* ALLOW_RECONFIGURE */


static void evermore_wrap(struct gps_device_t *session)
{
    gpsd_report(LOG_PROG, "evermore_wrap\n");
    (void) evermore_nmea_config(session, 0); /* configure NMEA messages to default */
}


/* this is everything we export */
struct gps_type_t evermore_binary =
{
    .type_name      = "EverMore binary",	/* full name of type */
    .trigger        = "$PEMT,", 		/* recognize the type */
    .channels       = EVERMORE_CHANNELS,	/* consumer-grade GPS */
    .probe_wakeup   = NULL,			/* no wakeup to be done before hunt */
    .probe_detect   = NULL,			/* no probe */
    .probe_subtype  = NULL,			/* no subtype probing */
#ifdef ALLOW_RECONFIGURE
    .configurator   = evermore_configurator,	/* switch to binary */
#endif /* ALLOW_RECONFIGURE */
    .get_packet     = generic_get,		/* use generic one */
    .parse_packet   = evermore_parse_input,	/* parse message packets */
    .rtcm_writer    = pass_rtcm,		/* send RTCM data straight */
    .speed_switcher = evermore_speed,		/* we can change baud rates */
    .mode_switcher  = evermore_mode,		/* there is a mode switcher */
    .rate_switcher  = NULL,			/* no sample-rate switcher */
    .cycle_chars    = -1,			/* ignore, no rate switch */
#ifdef ALLOW_RECONFIGURE
    .revert         = NULL,			/* reversion code */
#endif /* ALLOW_RECONFIGURE */
    .wrapup         = evermore_wrap,		/* wrapup method */
    .cycle          = 1,			/* updates every second */
};
#endif /* defined(EVERMORE_ENABLE) && defined(BINARY_ENABLE) */