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Solving program crashes caused by bluetooth GPS connection

Posted: Fri Mar 31, 2006 12:52 am
by Michael_Boelling
The Problem:
I had terrible problems when I used my O2 Xda mini (Windows Mobile 2003 SE) and the bluetooth SIRF III GPS receiver Navilock BT-338.
The program crashed several times and I had to do a soft reset every time. Usually it worked about 7 minutes sometimes more, sometimes less and then the device freezes so that I had to do a soft reset. Afterwards I had to remove the bluetooth device and reconnect it to get it work and even that doesn't help always. So how did I solve the problem.

How I got it work
Scott gave me the right hint. I had used 38.400 baud for the gps receiver as my GPS manual adviced me to do so and that is causing all the trouble. It did not help to set the transfer rate to 4.800 baud, I don't know why, but I renamed the file \My Device\My Documents\PathAway\PathawayDBV, so when I started Pathway next time a new Database was created. Then I set transfer rate to 4.800 baud and all worked well. O.k. sometimes when I open other programms at the same time, I get a little trouble, but when I close the bluetooth connection before I go to the other programs, there is no problem.

How I got into trouble again
O.k. So far so good (we say so in German).
I wanted to find out if it was really that transferrate that causes the trouble because I was thinking maybe my database was to big or missed up. So I renamed the databases and made shure the transfer rate was set correctly. And, it worked fine, no problem. So I tested the high transferrate of 38.400 baud and it worked . I was suprised and thought maybe there is something else. So I went for a testrun, 15 min no problems, through the forrest, and dammed. The f***ing prgrams crashed. Soft reset, set to 4.800 baud and dammed, crashed again. It does so many times and I was nearly going to crash it physically. But, o.k. last chance, I renamed the database made sure to work at 4.800 baud and everything works fine.
I am not going to test a different transferrate any more as it is really painfull to get it working again. So my suggestion: whatever happens: Stay at 4.800 baud.

Now I also found a program the speaks SIRF with my device. It is called SirfDemo and available at: ...
I found it at this page: ... C_ID=25575
It is quite interesting and you can for example set the transferrate for NMEA, but guess what, I am not going to change it.

Is the Power Safe Mode causing the problem?

Posted: Sat May 27, 2006 3:01 pm
by Michael_Boelling
The O2 device also has an additional power safe mode switched on by default. I switched it off and I was able do a complete balloon ride (1:30 h) with no disconnections and resets for the first time ever.
The bad news is, that now, when the O2 device sends an alarm, the device stays on and empties the batteries pretty soon. I hope this finally solves my problems. When I encounter diferent problems I will post them here.

Seems to work perfeclty now

Posted: Mon Jul 03, 2006 1:29 pm
by Michael_Boelling
I have done more than 10 balloon flights yet and no problems anymore with Pathaway. The O2 device itself still freezes sometimes, but not very often, and what do you expect from a Windows device.