Wardriving with the M5 a.k.a. who needs the Garmin SDK

[AKlopper]

WiFiFoFum is an 802.11 scanner that works with the Ambicom SD Wifi card that I use with my M5.

http://www.aspecto-software.com/WiFiFoFum/

The interesting thing about it is that it also works with the M5's built in GPS, as long as you configure it to point to COM2 as the GPS connection. This leads me to believe that Garmin have included NMEA support by default on the M5 (at least for applications running locally on the M5) which means that a great deal can probably be done without an official Garmin SDK.

[JMckie]

Interesting. How does Wififofum use the GPS?

[AKlopper]

It just records the current location for each access point that it discovers. Nothing fancy. I was more impressed with the fact that it worked at all with the GPS, and that Garmin seems to have provided a standard mechanism for accessing the GPS on the PPC that doesn't involve callbacks and custom SDKs.

[JMckie]

Interesting. I should try Wififofum with a GPS.

So it appears that the M5 outputs NMEA in addition as Garmin protocol for the Que apps. Do they run simultaneously, i.e. does Wififofum use the GPS while QueMap is navigating in the background?

If so, this is a clear advantage over the GPS10 which works in Garmin mode or NMEA mode but not at the same time.

[AKlopper]

I was wondering this myself, but I didn't get around to trying it (I forgot my stylus when I went out last night). I'll give it a try this evening. I need an external antenna to do this, as the Wifi antenna severely degrades GPS reception using the internal antenna.

[AKlopper]

It appears to be possible to use the Garmin apps at the same time that WiFiFoFum is reading NMEA data from COM2.

The lat/lon coordinates logged against APs that WiFiFoFum discovers seem to discover from a distinct time lag, however, as they are all spread out along a small section near the beginning of the track that I drove, rather than along the entire track (they definitely follow the correct track, though).

Also, the timestamp of the last known GPS position in WiFiFoFum starts out correct, but seems to increment a lot slower than the actual time, which indicates that it seems to be having trouble streaming NMEA data from the COM port for whatever reason.

At the moment I am assuming that the problem is with WiFiFoFum, so I'll have to find another PPC GPS app to play with in order to do some more testing.

And yes, I did try different COM port settings (4800 and 9600 baud, the NMEA and Garmin default respectively).

[AKlopper]

I forgot to mention that it is possible to use both the internal antenna and the Wifi card at the same time, as long as you let the GPS acquire a fair number of satellites before plugging in the Wifi card.

Once the M5 has a fix it seems to be able to hang onto it very well, despite very poor signal strengths.

[JMckie]

Might I suggest trying GPSTuner, which in the last beta that I tried had an option to log NMEA output. This would be invaluable in tracing back what happens if there is any lag.

One thing I would like to know is if DOP data is included in the NMEA output.

Regarding keeping a fix with very low signals, I was once able to drive around with the iQue's external antenna placed in the middle of and directly under the drivers seat. I couldn't believe it myself.

[AKlopper]

NMEA log file attached. This was done indoors with my Gilsson antenna in the window (it's raining outside).

[JMckie]

Yes, there they are! PDOP, HDOP, and VDOP just before the checksum "*39"

$GPGSA,A,3,01,05,06,11,14,18,20,22,25,30,37,,2.4,1 .7,1.6*39

In this aspect, this is a definite improvement over the iQue and the GPS10.

Good job Garmin.