Playing with a Holux M-241

Here is how to download tracks from the Holux M-241:

gpsbabel -t -r -w -i m241 -f /dev/ttyUSB0 -o gpx -F `date +'%Y-%m-%d-%H%M%S'`.gpx

It might work also via bluetooth, but I have not tried yet.

Now, until M-241 support will be released in a stable version of gpsbabel, here is how to compile the version from CVS.

Get the sources:

cvs login
cvs -z3 co -P gpsbabel

Untar this to debianise the sources.

If it does to compile because of some errors in lmx.c, apply this patch.

Then you can install the resulting package and (hopefully) be happy.

Note, after downloading the logs, gpsbabel currently turns on logging. Here is a patch to disable that behaviour.

Finally, if you want to hack around a little on the unit, you can play with mtkbabel: the source code is simple, and most of the MTK protocol is implemented, so you can easily feed your own commands to the MTK. Documentation about the commands can be found here:

The links are taken from a post in the GPSPasSion forum.

For a source of ideas of what commands you can send, you can look into the source code of BT747. For example, to set the M-241 to 2Hz fix, you can add this to mtkbabel:

$ret = packet_wait('PMTK001,300,3');

And if you want to set the MTK to an insane 5Hz fix rate, to take really fine grained gpx traces with your laptop, you can use this:

$ret = packet_wait('PMTK001,300,3');

Don't forget to set the serial speed to 38400 before talking with the unit:

stty 38400 < /dev/ttyUSB0