hacking the sony/etak gps1 pcmcia module/antenna

• lobster and magnet included. also has an IR transciever under the little "lump" on the outside of the pc card. between this lump and the card is a toggle to switch between NMEA and ETAK data modes (see below) and with them 4800baud/9600baud (respectively). The "hump" is secured by the body sticker for the top of the card, and two bolts located to either side of the hump (look underneath the card for the corresponding nuts). information to follow.

• NMEA emulation: doesn't work the way you think it would. It reports coordinates in the $GPGGA, $GPGLL, and $GPRMC lines, but has a number of key deviations. First of all, it uses neither degree.decimal NOR sexigesimal notation: instead it reports degreesminutes.deciminutes: this means that you need to do some tricks to convert this data regardless of which format you want to use the data in. NMEA appears to expect degree.decimal format (shifted by 100s power), so this means that this WON'T be compatible with most NMEA software. Also, note that while the "lock" field is consistently empty (at least on mine), the number of satellites works correctly; inconveniently, even when it has NO satellites, this little pain keeps sending the last known coordinates with 00 satellites, unlike garmins that don't appear to say anything if they don't know where they are.
• etak mode:
works like the sony pyxis protocol, as documented here. (thanks!). But the gps coordinates are still different. Note that while this protocol's nonstandard, it is EASIER to parse than NMEA, and that it provides elevation information NOT included in the NMEA emulation mode.

• Basically, the pcmcia card asks to be a serial port. It was detected like a charm with the pccom driver under openbsd 2.9 and 3.0. This mounts it as a read-only character device; likely /dev/cua03 under Open, unless you have other devices fighting for serial ids. You can run minicom against these ports with a command-line argument. remember to set your tty speed correctly, or it'll just look like garbage under minicom/through any serial FD open.(in ETAK mode, this is 9600 baud, in NMEA, use 4800 baud.)
• using in h1kari's dstumbler: it's possible. with certain modifications to gps.c (see the protocol differences in NMEA mode above. this should also be possible using the ETAK protocol if you're brave). perhaps the pseudo-NMEA or etak will be rolled into future dstumblers.

• It comes with a windows driver for Windows 9x only. Don't use it. if you coerce the device to install as a serial port, it'll work (with the skymap software, even) under any windows 9x/NT variant (including 2k), as well as allow you to view the device's output with your favorite terminal program. This means that with app-side driver modifications for the GPS, this could work with Marius Milner's netstumbler software, but isn't supported at the time of this writing (translation: i haven't asked him yet). The reasons for current incompatibilities are detailed in the protocol section above.

• coming soon!