コード例 #1
0
ファイル: monitor_nmea0183.c プロジェクト: fhgwright/gpsd
static void monitor_nmea_send(const char *fmt, ...)
{
    char buf[BUFSIZ];
    va_list ap;

    va_start(ap, fmt);
    (void)vsnprintf(buf, sizeof(buf) - 5, fmt, ap);
    va_end(ap);
    (void)monitor_control_send((unsigned char *)buf, strlen(buf));
}
コード例 #2
0
ファイル: monitor_sirf.c プロジェクト: elfchief/gpsd
static bool sirf_initialize(void)
{
    unsigned int i;

    mid2win = subwin(devicewin, 6, 80, 1, 0);
    mid4win = subwin(devicewin, SIRF_CHANNELS + 3, 30, 7, 0);
    mid6win = subwin(devicewin, 3, 50, 7, 30);
    mid7win = subwin(devicewin, 4, 50, 13, 30);
    mid9win = subwin(devicewin, 3, 50, 10, 30);
    mid13win = subwin(devicewin, 3, 50, 17, 30);
    mid19win = newwin(16, 50, 7, 30);
    mid27win = subwin(devicewin, 3, 50, 20, 30);
    if (mid2win == NULL || mid4win == NULL || mid6win == NULL
	|| mid9win == NULL || mid13win == NULL || mid19win == NULL
	|| mid27win == NULL)
	return false;

    (void)syncok(mid2win, true);
    (void)syncok(mid4win, true);
    (void)syncok(mid6win, true);
    (void)syncok(mid7win, true);
    (void)syncok(mid9win, true);
    (void)syncok(mid13win, true);
    (void)syncok(mid27win, true);

    (void)wborder(mid2win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid2win, A_BOLD);
    (void)wmove(mid2win, 0, 1);
    display(mid2win, 0, 12, " X ");
    display(mid2win, 0, 21, " Y ");
    display(mid2win, 0, 30, " Z ");
    display(mid2win, 0, 43, " North ");
    display(mid2win, 0, 54, " East ");
    display(mid2win, 0, 65, " Alt ");

    (void)wmove(mid2win, 1, 1);
    (void)wprintw(mid2win,
		  "Pos:                            m                                    m");
    (void)wmove(mid2win, 2, 1);
    (void)wprintw(mid2win,
		  "Vel:                            m/s                                  climb m/s");
    (void)wmove(mid2win, 3, 1);
    (void)wprintw(mid2win,
		  "Time:                          Leap:        Heading:                 speed m/s");
    (void)wmove(mid2win, 4, 1);
    (void)wprintw(mid2win,
		  "Fix:                                                 HDOP:      M1:     M2:   ");
    display(mid2win, 5, 24, " Packet type 2 (0x02) ");
    (void)wattrset(mid2win, A_NORMAL);

    (void)wborder(mid4win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid4win, A_BOLD);
    display(mid4win, 1, 1, "Ch PRN  Az El Stat  C/N ? SF");
    for (i = 0; i < SIRF_CHANNELS; i++) {
	display(mid4win, (int)(i + 2), 1, "%2d", i);
    }
    display(mid4win, 0, 1, " Measured Tracker ");
    display(mid4win, 14, 4, " Packet Type 4 (0x04) ");
    (void)wattrset(mid4win, A_NORMAL);

    (void)wborder(mid19win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid19win, A_BOLD);
    display(mid19win, 1, 1, "Alt. hold mode:");
    display(mid19win, 2, 1, "Alt. hold source:");
    display(mid19win, 3, 1, "Alt. source input:");
    display(mid19win, 4, 1, "Degraded timeout:");
    display(mid19win, 5, 1, "DR timeout:");
    display(mid19win, 6, 1, "Track smooth mode:");
    display(mid19win, 7, 1, "Static Navigation:");
    display(mid19win, 8, 1, "3SV Least Squares:");
    display(mid19win, 9, 1, "DOP Mask mode:");
    display(mid19win, 10, 1, "Nav. Elev. mask:");
    display(mid19win, 11, 1, "Nav. Power mask:");
    display(mid19win, 12, 1, "DGPS Source:");
    display(mid19win, 13, 1, "DGPS Mode:");
    display(mid19win, 14, 1, "DGPS Timeout:");
    display(mid19win, 1, 26, "LP Push-to-Fix:");
    display(mid19win, 2, 26, "LP On Time:");
    display(mid19win, 3, 26, "LP Interval:");
    display(mid19win, 4, 26, "U. Tasks Enab.:");
    display(mid19win, 5, 26, "U. Task Inter.:");
    display(mid19win, 6, 26, "LP Pwr Cyc En:");
    display(mid19win, 7, 26, "LP Max Acq Srch:");
    display(mid19win, 8, 26, "LP Max Off Time:");
    display(mid19win, 9, 26, "APM enabled:");
    display(mid19win, 10, 26, "# of Fixes:");
    display(mid19win, 11, 26, "Time btw Fixes:");
    display(mid19win, 12, 26, "H/V Error Max:");
    display(mid19win, 13, 26, "Rsp Time Max:");
    display(mid19win, 14, 26, "Time/Accu:");

    display(mid19win, 15, 8, " Packet type 19 (0x13) ");
    (void)wattrset(mid19win, A_NORMAL);

    (void)wborder(mid6win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid6win, A_BOLD);
    display(mid6win, 0, 1, " Firmware Version ");
    display(mid6win, 2, 8, " Packet Type 6 (0x06) ");
    (void)wattrset(mid6win, A_NORMAL);

    (void)wborder(mid7win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid7win, A_BOLD);
    display(mid7win, 0, 1, " Clock Status ");
    display(mid7win, 1, 1, "SVs: ");
    display(mid7win, 1, 9, "Drift: ");
    display(mid7win, 1, 23, "Bias: ");
    display(mid7win, 2, 1, "GPS Time: ");
    display(mid7win, 2, 23, "PPS: ");
    (void)syncok(mid7win, true);
#ifndef PPS_ENABLE
    (void)mvwaddstr(mid7win, 2, 40, "N/A");
#endif /* PPS_ENABLE */
    display(mid7win, 3, 8, " Packet type 7 (0x07) ");
    (void)wattrset(mid7win, A_NORMAL);

    (void)wborder(mid9win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid9win, A_BOLD);
    display(mid9win, 0, 1, " CPU Throughput ");
    display(mid9win, 1, 1, "Max: ");
    display(mid9win, 1, 13, "Lat: ");
    display(mid9win, 1, 25, "Time: ");
    display(mid9win, 1, 39, "MS: ");
    display(mid9win, 2, 8, " Packet type 9 (0x09) ");
    (void)wattrset(mid9win, A_NORMAL);

    (void)wborder(mid13win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid13win, A_BOLD);
    display(mid13win, 0, 1, " Visible List ");
    display(mid13win, 2, 8, " Packet type 13 (0x0D) ");
    (void)wattrset(mid13win, A_NORMAL);

    (void)wborder(mid27win, 0, 0, 0, 0, 0, 0, 0, 0),
	(void)wattrset(mid27win, A_BOLD);
    display(mid27win, 0, 1, " DGPS Status ");
    display(mid27win, 2, 8, " Packet type 27 (0x1B) ");
    (void)wattrset(mid27win, A_NORMAL);

#ifdef CONTROLSEND_ENABLE
    /* probe for version */
    (void)monitor_control_send((unsigned char *)"\x84\x00", 2);
#endif /* CONTROLSEND_ENABLE */

    /* initialize the GPS context's time fields */
    gpsd_time_init(session.context, time(NULL));

    return true;
}
コード例 #3
0
ファイル: monitor_sirf.c プロジェクト: elfchief/gpsd
static void sirf_update(void)
{
    int i, j, ch, sv;
    unsigned char *buf;
    size_t len;
    uint8_t dgps;
    char tbuf[JSON_DATE_MAX+1];

    buf = session.lexer.outbuffer + 4;
    len = session.lexer.outbuflen - 8;
    switch (buf[0]) {
    case 0x02:			/* Measured Navigation Data */
	(void)wmove(mid2win, 1, 6);	/* ECEF position */
	(void)wprintw(mid2win, "%8d %8d %8d", getbes32(buf, 1),
		      getbes32(buf, 5), getbes32(buf, 9));
	(void)wmove(mid2win, 2, 6);	/* ECEF velocity */
	(void)wprintw(mid2win, "%8.1f %8.1f %8.1f",
		      (double)getbes16(buf, 13) / 8, (double)getbes16(buf,
								    15) / 8,
		      (double)getbes16(buf, 17) / 8);
	decode_ecef((double)getbes32(buf, 1), (double)getbes32(buf, 5),
		    (double)getbes32(buf, 9), (double)getbes16(buf, 13) / 8,
		    (double)getbes16(buf, 15) / 8, (double)getbes16(buf,
								  17) / 8);
	/* line 3 */
	(void)wmove(mid2win, 3, 7);
	(void)wprintw(mid2win, "%-24s",
			unix_to_iso8601(session.gpsdata.fix.time, tbuf, sizeof(tbuf))
			);
	(void)wmove(mid2win, 3, 38);
	(void)wattrset(mid2win, A_UNDERLINE);
	if (ppstime_enabled)
	   (void)wprintw(mid2win, "%02d", leapseconds);
	else
	   (void)wprintw(mid2win, "??");
	(void)wattrset(mid2win, A_NORMAL);
	/* line 4 */
	/* HDOP */
	(void)wmove(mid2win, 4, 59);
	(void)wprintw(mid2win, "%4.1f", (double)getub(buf, 20) / 5);
	/* Mode 1 */
	(void)wmove(mid2win, 4, 69);
	(void)wprintw(mid2win, "%02x", getub(buf, 19));
	/* Mode 2 */
	(void)wmove(mid2win, 4, 77);
	(void)wprintw(mid2win, "%02x", getub(buf, 21));
	/* SVs in fix */
	(void)wmove(mid2win, 4, 6);
	(void)wprintw(mid2win, "%2d =                                     ",
		      (int)getub(buf, 28));
	/* SV list */
	(void)wmove(mid2win, 4, 10);
	/* coverity_submit[tainted_data] */
	for (i = 0; i < (int)getub(buf, 28); i++)
	   (void)wprintw(mid2win, " %2d", (int)getub(buf, 29 + i));
	monitor_log("MND 0x02=");
	break;

    case 0x04:			/* Measured Tracking Data */
	ch = (int)getub(buf, 7);
	for (i = 0; i < ch; i++) {
	    int az, el, state, off;
	    double cn;

	    off = 8 + 15 * i;
	    (void)wmove(mid4win, i + 2, 3);

	    sv = (int)getub(buf, off);
	    az = (int)getub(buf, off + 1) * 3 / 2;
	    el = (int)getub(buf, off + 2) / 2;
	    state = (int)getbeu16(buf, off + 3);
	    cn = 0;
	    for (j = 0; j < 10; j++)
		cn += (int)getub(buf, off + 5 + j);
	    cn /= 10;

	    (void)wprintw(mid4win, " %3d %3d %2d %04x %4.1f %c",
			   sv, az, el, state, cn, state == 0xbf ? 'T' : ' ');
	}
	monitor_log("MTD 0x04=");
	break;

#ifdef __UNUSED__
    case 0x05:			/* raw track data */
	for (off = 1; off < len; off += 51) {
	    ch = getbeu32(buf, off);
	    (void)wmove(mid4win, ch + 2, 19);
	    cn = 0;

	    for (j = 0; j < 10; j++)
		cn += getub(buf, off + 34 + j);

	    printw("%5.1f", (double)cn / 10);

	    printw("%9d%3d%5d", getbeu32(buf, off + 8),
		   (int)getbeu16(buf, off + 12), (int)getbeu16(buf, off + 14));
	    printw("%8.5f %10.5f", (double)getbeu32(buf, off + 16) / 65536,
		   (double)getbeu32(buf, off + 20) / 1024);
	}
	monitor_log("RTD 0x05=");
	break;
#endif /* __UNUSED */

    case 0x06:			/* firmware version */
	display(mid6win, 1, 1, "%s", buf + 1);
	monitor_log("FV  0x06=");
	break;

    case 0x07:			/* Response - Clock Status Data */
	display(mid7win, 1, 5, "%2d", getub(buf, 7));	/* SVs */
	display(mid7win, 1, 16, "%lu", getbeu32(buf, 8));	/* Clock ppstimes */
	display(mid7win, 1, 29, "%lu", getbeu32(buf, 12));	/* Clock Bias */
	display(mid7win, 2, 11, "%lu", getbeu32(buf, 16));	/* Estimated Time */
	monitor_log("CSD 0x07=");
	break;

    case 0x08:			/* 50 BPS data */
	ch = (int)getub(buf, 1);
	sv = (int)getub(buf, 2);
	display(mid4win, ch + 2, 27, "%2d", sv);
	subframe_enabled = true;
	monitor_log("50B 0x08=");
	break;

    case 0x09:			/* Throughput */
	display(mid9win, 1, 6, "%.3f", (double)getbeu16(buf, 1) / 186);	/*SegStatMax */
	display(mid9win, 1, 18, "%.3f", (double)getbeu16(buf, 3) / 186);	/*SegStatLat */
	display(mid9win, 1, 31, "%.3f", (double)getbeu16(buf, 5) / 186);	/*SegStatTime */
	display(mid9win, 1, 42, "%3d", (int)getbeu16(buf, 7));	/* Last Millisecond */
	monitor_log("THR 0x09=");
	break;

    case 0x0b:			/* Command Acknowledgement */
	monitor_log("ACK 0x0b=");
	break;

    case 0x0c:			/* Command NAcknowledgement */
	monitor_log("NAK 0x0c=");
	break;

    case 0x0d:			/* Visible List */
	display(mid13win, 1, 1, "%02d =                                            ",
				 getub(buf, 1));
	(void)wmove(mid13win, 1, 5);
	for (i = 0; i < (int)getub(buf, 1); i++)
	    (void)wprintw(mid13win, " %d", getub(buf, 2 + 5 * i));
	monitor_log("VL  0x0d=");
	break;

    case 0x13:
#define YESNO(n)	(((int)getub(buf, n) != 0)?'Y':'N')
	display(mid19win, 1, 20, "%d", getub(buf, 5));	/* Alt. hold mode */
	display(mid19win, 2, 20, "%d", getub(buf, 6));	/* Alt. hold source */
	display(mid19win, 3, 20, "%dm", (int)getbeu16(buf, 7));	/* Alt. source input */
	if (getub(buf, 9) != (uint8_t) '\0')
	    display(mid19win, 4, 20, "%dsec", getub(buf, 10));	/* Degraded timeout */
	else
	    display(mid19win, 4, 20, "N/A   ");
	display(mid19win, 5, 20, "%dsec", getub(buf, 11));	/* DR timeout */
	display(mid19win, 6, 20, "%c", YESNO(12));	/* Track smooth mode */
	display(mid19win, 7, 20, "%c", YESNO(13));	/* Static Nav. */
	display(mid19win, 8, 20, "0x%x", getub(buf, 14));	/* 3SV Least Squares */
	display(mid19win, 9, 20, "0x%x", getub(buf, 19));	/* DOP Mask mode */
	display(mid19win, 10, 20, "0x%x", (int)getbeu16(buf, 20));	/* Nav. Elev. mask */
	display(mid19win, 11, 20, "0x%x", getub(buf, 22));	/* Nav. Power mask */
	display(mid19win, 12, 20, "0x%x", getub(buf, 27));	/* DGPS Source */
	display(mid19win, 13, 20, "0x%x", getub(buf, 28));	/* DGPS Mode */
	display(mid19win, 14, 20, "%dsec", getub(buf, 29));	/* DGPS Timeout */
	display(mid19win, 1, 42, "%c", YESNO(34));	/* LP Push-to-Fix */
	display(mid19win, 2, 42, "%dms", getbeu32(buf, 35));	/* LP On Time */
	display(mid19win, 3, 42, "%d", getbeu32(buf, 39));	/* LP Interval */
	display(mid19win, 4, 42, "%c", YESNO(43));	/* User Tasks enabled */
	display(mid19win, 5, 42, "%d", getbeu32(buf, 44));	/* User Task Interval */
	display(mid19win, 6, 42, "%c", YESNO(48));	/* LP Power Cycling Enabled */
	display(mid19win, 7, 42, "%d", getbeu32(buf, 49));	/* LP Max Acq Search Time */
	display(mid19win, 8, 42, "%d", getbeu32(buf, 53));	/* LP Max Off Time */
	display(mid19win, 9, 42, "%c", YESNO(57));	/* APM Enabled */
	display(mid19win, 10, 42, "%d", (int)getbeu16(buf, 58));	/* # of fixes */
	display(mid19win, 11, 42, "%d", (int)getbeu16(buf, 60));	/* Time Between fixes */
	display(mid19win, 12, 42, "%d", getub(buf, 62));	/* H/V Error Max */
	display(mid19win, 13, 42, "%d", getub(buf, 63));	/* Response Time Max */
	display(mid19win, 14, 42, "%d", getub(buf, 64));	/* Time/Accu & Duty Cycle Priority */
#undef YESNO
	monitor_log("NP  0x13=");
	break;

    case 0x1b:
	/******************************************************************
	 Not actually documented in any published materials before the
	 1.6 version of the SiRF binary protocol manual.
	 Here is what Chris Kuethe got from the SiRF folks,
	 (plus some corrections from the GpsPaSsion forums):

	Start of message
	----------------
	Message ID          1 byte    27
	Correction Source   1 byte    0=None, 1=SBAS, 2=Serial, 3=Beacon,
	4=Software

	total:              2 bytes

	Middle part of message varies if using beacon or other:
	-------------------------------------------------------
	If Beacon:
	Receiver Freq Hz    4 bytes
	Bit rate BPS        1 byte
	Status bit map      1 byte    01=Signal Valid,
				      02=Auto frequency detect
				      04=Auto bit rate detect
	Signal Magnitude    4 bytes   Note: in internal units
	Signal Strength dB  2 bytes   derived from Signal Magnitude
	SNR  dB             2 bytes

	total:             14 bytes

	If Not Beacon:
	Correction Age[12]  1 byte x 12  Age in seconds in same order as follows
	Reserved            2 bytes

	total:             14 bytes

	End of Message
	--------------
	Repeated 12 times (pad with 0 if less than 12 SV corrections):
	SVID                1 byte
	Correction (cm)     2 bytes (signed short)

	total               3 x 12 = 36 bytes
	******************************************************************/
	dgps = getub(buf, 1);
	display(mid27win, 1, 1, "%8s =                                      ",
		(CHECK_RANGE(dgpsvec, dgps) ? dgpsvec[dgps] : "???"));
	(void)wmove(mid27win, 1, 11);
	for (ch = 0; ch < SIRF_CHANNELS; ch++)
	    if (getub(buf, 16 + 3 * ch) != '\0')
		(void)wprintw(mid27win, " %d", getub(buf, 16 + 3 * ch));
	monitor_log("DST 0x1b=");
	break;

    case 0x1c:			/* NL Measurement Data */
    case 0x1d:			/* NL DGPS Data */
    case 0x1e:			/* NL SV State Data */
    case 0x1f:			/* NL Initialized Data */
	subframe_enabled = true;
	monitor_log("NL  0x%02x=", buf[0]);
	break;

    case 0x29:			/* Geodetic Navigation Data */
	monitor_log("GND 0x29=");
	break;

    case 0x32:			/* SBAS Parameters */
	monitor_log("SBP 0x32=");
	break;

    case 0x34:			/* PPS Time */
	ppstime_enabled = true;
	leapseconds = (int)getbeu16(buf, 8);
	monitor_log("PPS 0x34=");
	break;

    case 0xff:			/* Development Data */
	while (len > 0 && buf[len - 1] == '\n')
	    len--;
	while (len > 0 && buf[len - 1] == ' ')
	    len--;
	buf[len] = '\0';
	j = 1;
	for (i = 0; verbpat[i] != NULL; i++)
	    if (str_starts_with((char *)(buf + 1), verbpat[i])) {
		j = 0;
		break;
	    }
	if (j != 0)
	    monitor_log("%s\n", buf + 1);
	monitor_log("DD  0xff=");
	break;

    default:
	monitor_log("UNK 0x%02x=", buf[0]);
	break;
    }

#ifdef CONTROLSEND_ENABLE
    /* elicit navigation parameters */
    if (dispmode && (time(NULL) % 10 == 0)) {
	(void)monitor_control_send((unsigned char *)"\x98\x00", 2);
    }
#endif /* CONTROLSEND_ENABLE */

    /* clear the 50bps data field every 6 seconds */
    if (subframe_enabled && (time(NULL) % 6 == 0)) {
	for (ch = 0; ch < SIRF_CHANNELS; ch++)
	   display(mid4win, ch + 2, 27, "  ");
    }

    if (dispmode) {
	(void)touchwin(mid19win);
	(void)wnoutrefresh(mid19win);
    }

#ifdef PPS_ENABLE
    pps_update(mid7win, 2, 32);
#endif /* PPS_ENABLE */
}
コード例 #4
0
ファイル: monitor_sirf.c プロジェクト: elfchief/gpsd
static int sirf_command(char line[])
{
    unsigned char buf[BUFSIZ];
    int v;

    switch (line[0]) {
    case 'A':			/* toggle 50bps subframe data */
	(void)memset(buf, '\0', sizeof(buf));
	putbyte(buf, 0, 0x80);
	putbyte(buf, 23, 0x0c);
	putbyte(buf, 24, subframe_enabled ? 0x00 : 0x10);
	(void)monitor_control_send(buf, 25);
	/*
	 * The subframe_enabled off because we're counting on receipt of
	 * a subframe packet to turn it on if the command succeeds.
	 */
	subframe_enabled = false;
	return COMMAND_MATCH;

    case 'M':			/* static navigation */
	putbyte(buf, 0, 0x8f);	/* id */
	putbyte(buf, 1, atoi(line + 1));
	(void)monitor_control_send(buf, 2);
	return COMMAND_MATCH;

    case 'D':			/* MID 4 rate change (undocumented) */
	v = atoi(line + 1);
	if (v > 30)
	    return COMMAND_MATCH;
	putbyte(buf, 0, 0xa6);
	putbyte(buf, 1, 0);
	putbyte(buf, 2, 4);	/* satellite picture */
	putbyte(buf, 3, v);
	putbyte(buf, 4, 0);
	putbyte(buf, 5, 0);
	putbyte(buf, 6, 0);
	putbyte(buf, 7, 0);
	(void)monitor_control_send(buf, 8);
	return COMMAND_MATCH;

    case 'P':			/* poll navigation params */
	dispmode = !dispmode;
	if (dispmode) {
	    (void)syncok(mid6win, false);
	    (void)syncok(mid7win, false);
	    (void)syncok(mid9win, false);
	    (void)syncok(mid13win, false);
	    (void)syncok(mid27win, false);
	} else {
	    (void)syncok(mid6win, true);
	    (void)wsyncup(mid6win);
	    (void)syncok(mid7win, true);
	    (void)wsyncup(mid7win);
	    (void)syncok(mid9win, true);
	    (void)wsyncup(mid9win);
	    (void)syncok(mid13win, true);
	    (void)wsyncup(mid13win);
	    (void)syncok(mid27win, true);
	    (void)wsyncup(mid27win);
	}
	return COMMAND_MATCH;
    }

    return COMMAND_UNKNOWN;	/* no match */
}
コード例 #5
0
static void garmin_bin_ser_update(void)
{
   unsigned char *buf;
   size_t len;
   uint16_t pkt_id;
   uint32_t pkt_size;
   unsigned char pkt_data[255];
   int i, j;
   unsigned char c;
   unsigned char chksum;
   bool pkt_good = false, got_dle = false;

   buf = session.lexer.outbuffer;
   len = session.lexer.outbuflen;

   if (!(buf[0] == (unsigned char)0x10 &&		/* DLE */
		buf[len-2] == (unsigned char)0x10 &&	/* DLE */
		buf[len-1] == (unsigned char)0x03))	/* ETX */
	goto end;	/* bad pkt */

   if (buf[1] == (unsigned char)0x10 && buf[2] != (unsigned char)0x10)
	goto end;	/* bad pkt */
   pkt_id = (uint16_t)buf[1];

   if (buf[2] == (unsigned char)0x10 && buf[3] != (unsigned char)0x10)
	goto end;	/* bad pkt */
   pkt_size = (uint32_t)buf[2];

   chksum = buf[1] + buf[2];	/* pkt_id + pkt_size */

   j = 0;
   for (i = 0; i <= 255; i++) {
	if (pkt_size == (uint32_t)j)
	   break;
	c = buf[i+3];
	if (got_dle) {
	   got_dle = false;
	   if (c != (unsigned char)0x10)
		goto end;	/* bad pkt */
	} else {
	   pkt_data[j++] = c;
	   chksum += c;
	   if (c == (unsigned char)0x10)
		got_dle = true;
	}
   }

   /* check pkt chksum */
   if ((unsigned char)(-chksum) == buf[len-3])
	pkt_good = true;

   end:
   if (pkt_good) {
#ifdef CONTROLSEND_ENABLE
	if(serial)
	   /* good packet, send ACK */
	   (void)monitor_control_send((unsigned char *)"\x10\x06\x00\xfa\x10\x03", 6);
#endif
	garmin_bin_update(pkt_id, pkt_size, pkt_data);
   } else {
#ifdef CONTROLSEND_ENABLE
	if(serial)
	   /* bad packet, send NAK */
	   (void)monitor_control_send((unsigned char *)"\x10\x15\x00\xeb\x10\x03", 6);
#endif
	monitor_log("BAD 0x%02x=", buf[1]);
   }
}