J2ME on Sony Ericsson P1i

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Hi all,

I don't know if there are plans to improve the J2ME version, but I think it's a good option for a long lasting battery logger device. I'm experimenting with an old phone to make it a GPS logger.

BT747 J2ME version works very bad on my Sony Ericsson P1i Symbian UIQ3. Menus randomly not receive clicks or randomly quit. Checkboxes of what fields to log are never stored and that page cannot be scrolled. Scrolling also quits most pages.

I'm guessing these problems are originating from J4ME library, which looks totally abandoned.

Are there any plans to continue this version of BT747 or if you have any recommendations - what to do - please tell me. For start, I'm logging with MobileTrailExplorer, one of the few apps that worked.


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Hi I confirm that J4ME that I


I confirm that J4ME that I used to build the J2ME version is not maintained.  As J4ME is open-source any shortcoming of it could be fixed.

If you want to make a GPS Logger out of a phone, BT747 may not be the best code base as it does not currently read the GPS position provided by the phone.  I suggest that you look at http://qcontinuum.org/gpstrack/ .

I do not have plans to evolve BT747 for J2ME but I am willing to guide anybody who wants to evolve it.

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Hi, Ok, thanks for reply. I


Ok, thanks for reply. I don't know how to code j2me, and I'm afraid it is too late to get into it nowadays. :-(

According to OpenStreetMap Wiki, gpstrack does not save enough data to be used with OSM, for example no timestamps in the GPX file, thus not possible to upload to OSM, no accuracy data. Some people improved it, but their version's URL is not valid anymore and I got no reply to mailing them.

Unfortunately many J2ME software's Homepage leads to nonexisting files or nonexisting domains. I found 2 that works OK, however they are overshot, with too many features, map display and so on...

MobileTrailExplorer http://www.substanceofcode.com/software/mobile-trail-explorer/
MapNav http://www.mapnav.spb.ru/site/page.php?15

(I'm using external GPS and BT747 was able to get position, the main problems are with GUI totally not working. But I understand that you don't plan to develop it.)

Thank you anyway,

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Hi BT747 does not do the data


BT747 does not do the data logging itself - the GPS device logs the data.  BT747 is mainly to control/read the GPS Data Logger.

One of the issues that I encountered in the past was the difference between J2ME devices/setups and hence a requirement to debug the app on many more devices to make it stable.

Adapting gpstrack to include time or to increase the number of logged positions should not be too hard, but it does require a minimum set of J2ME coding skills... 

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Hi, Oh, I see, then I


Oh, I see, then I misunderstood! So it's similar to PC edition that I use with my Holix M1000-C.

But the GPS that I want to use with J2ME does not itself store a log, so I'll use other programs.

ps: please note that this site says that sending mails failed and if the problem persists, we should mail administrator. E.g. when I submitted the post above, also when I registered I think.

Thank you,

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The error message from top of

The error message from top of the page, if you are not aware of it:

"Unable to send e-mail. Please contact the site administrator if the problem persists."

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Hi, thanks for the

Hi, thanks for the information about the issue of ending mail - for some reason the target address is empty and I haven't found where to change that.  It looks like the address is ok in the configuration screen(s)...