[NTLK] Newton GPS prob: "GPS: 0" -----

From: DJ Vollkasko (DJ_Vollkasko_at_gmx.net)
Date: Fri Apr 29 2005 - 14:06:58 PDT


Okay, additional observations. Come on, please, grab your drink and =20
follow me outside the Vollkasko-Mansion into our spacious estate... =20
Mind the step... Nice evening, no? Lots of sky, too, so...

There, let's put everything on that table and start. Following good =20
advice that I have been given bc, we will let the setup sit undisturbed =20=

for a few minutes -- let's say ten, shall we? -- after the application =20=

starts and the receiver is powered up.

GPS Map:

Settings as previously reported:

        "GPS Driver: NMEA 183
                Interface Settings
                        Port: Serial Port
                        Speed: 4800
                        Parity: None
                        Handshake: None
                        Data Bits: 8
                        Stop Bits: 1
                        UTC Offset: -01:00
                        Init String: (blank)."

Changed serial speed from 4800 to first 9600 and then 2400:

1. When I first used 4800, I got "Waiting for GPS Data!", then "GPS: =20
n/a" and finally "GPS: 0".
2.-3. With the other two settings, the Nav window didn't change from =20
"Waiting for...", just stayed there, no matter how long it I let it =20
stand.

In each of these three tests, the GPS receiver (plugged in to =20
InterConnect port via dongle and Adriano's NewtNav) started when GPS =20
Map was started (steady LED) and then acquired a position (blinking =20
LED). It's really nice how the mouse is powered from the Newton -- =20
doesn't pull any power when no GPS application is running, starts with =20=

application, and transfers data nicely via the same cable connection, =20=

as the following TeleType GPS test shows.

TeleType GPS:

1. Started TT GPS. Green light on at GPS receiver.
2. The little GPS data bar shows only "???"s.
3. Change to "Position" screen, a popup opens informing me kindly

        "(i) TeleType GPS
        An unexpected error has occured.
        Error code =3D 2082399280
                                                        [X]"

4. The position window in the background shows data... Close popup, =20
read data:

        "Latitude ##,#######=B0
        Longitude -##,#######=B0
        (...)
        Satellites: 0"
        Time: 000000"

####etc. are decent looking numberstrings, of course, and the cute =20
little satellite dish icon shows (between (i) and [X]).

Back to start and now trying TT GPS's Monitor modus:

1. Start TT GPS. Green LED. Switch to Monitor mode.
2. In monitor mode some conversation comes in from the receiver. After =20=

one or two screens, error strikes again, but this time Error code =3D =20=

208230056.
3. Close error popup, read the last Monitor screen:

"$GPGGA,191757.402,####.####,N,####.####,E,1,04,2.0,172.6,M,,,,0000
$GPVTG,,T,,M,0.00,N0.0,K,A
$GPRMC,191757.402,A,####.####,N,####.####,E,0.00,,290405,,,A"

4. Following a pointer by Dr. M. Briley, resident astrophysicist at =20
NTLK, above translates like this:

$GPGGA is telling us the Global Positioning System Fix Data
                        191757.402 is the time of fix (UTC)
                        ####.####,N is the latitude (only the GPS gives =20=

out real numbers, but the Superior Secrecy Enhancer here in the Bat =20
Cave, errh, Vollkasko-Mansion automatically overwrites this with #...)
                        ####.####,W is the longitude
                        Next datum is the fix quality (0 =3D invalid, 1 =
=3D =20
gps fix, 2 =3D dgps fix), we get "1", which is good.
                        Next datum is the number of sats being tracked, =20=

in our case 04 =3D 4 sats. Sweet.
                        and other stuff.

$GPRMC is telling us the minimum specific GPS/Transit data
                        191757.402 is the time of position fix again
                        ####.####, N is the latitutde
                        ####.####,W is the longitude
                        Next datum is a nav. receiver warning. V =3D =20
warning, and A here means "OK"
                        0.00 is our speed over ground (knots), between =20=

",," should Course Heading (no course, no heading ;=3D} )
                        290405 is date of fix
                        and other stuff, incl. a checksum, which we =20
don't see transmitted. Could that be the problem?

$GPVTG gives us "Track made good and ground speed", but as we don't =20
move, there's only zeros and blanks, which is perfectly fine.

So we have established the following points:

        1. There *is* a signal being transmitted from the receiver. The =20=

NewtNav works just the way Adriano, Ron and I wanted it -- it pulls =20
power off the Newt and feeds it back sweet and delicious GPS data.
        2. The receiver works and is able to get a fix. It is able to =
let the =20
Newton know about what it has.
        3. TT GPS plays with the receiver, but somehow breaks off their =
date. =20
An allergic reaction? Any therapy?
        4. GPS Map plays shy with the receiver data. Speed settings of =
2400 =20
and 9600 are not popular with GPS Map, 4800 at least gets GPS Map to =20
acknowledge that, yes, there is a GPS receiver it can disown and ignore =20=

(though I wonder what such a pretty software would gain by such awful =20=

and impolite behaviour towards an obviously non-brand receiver kid...).

                        *** So how can I get GPS Map to play nice? ***

>There is an NMEA $PGRMO command you can send to your receiver
>enabling/disabling output sentences.

How to do it? Via Init-string window? What string, what settings?

DJV.

P.S.: Following Johannes and much bc advice, I would like to connect =20
the AQ-300 to my PowerBook to see what happens with the software sold =20=

along by the manufacturer. Unfortunately, I don't have the PS/2-to-USB =20=

cable necessary for this (maybe next week). But I've put the AQ-300 =20
manual up at the Temporary Library, as there is NOTHING on the =20
manufacturer's website http://www.aqmax.com in either English, German, =20=

French, Italian or Spanish, and the download page doesn't load at all. =20=

For the time being: =20
http://www.stillnewt.org/library/_Software/_GPS%20Software/=20
AQ%20max%20AQ-300%20Manual%20(GPS%20Mouse)/ .=

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