GPS tracker Holux m241

Thank you for the feedback. Despite the fact that I am subscribed to this topic, I do not get e-mail updates ;-(, so I did not repond earlier.

The English documentation still has to be written - most question are already anwsered in the German Documentation for example.

For the moment, the INFO tab shows the error messages. Some indication of why the connection fails can be found there. On linux, your problem might be the you are running in 64 bit. From the web start, I need to investigate if I can select the right driver automatically somehow. In the zip file I need to do a similar thing - in the “” file you’ld need to have ‘RXTXLIBPATH=${RXTXPATH}/Linux/x86_64-unknown-linux-gnu’ .

Regarding the separation of log downloading and log configuration. I am open to suggestions, but I do not really have good ideas on how to do more. Currently, when not connected, all operations that are not possible are greyed out. There are just two buttons related to the log download that are disabled - they are on the first tab. The others are all related to device configuration.
As can be noted, the first three tabs are related to log download and conversion. ‘Device Settings’ and ‘Advanced Device Settings’ are as indicated by the title. Advanced File Settings is related to log conversion again, but these are settings that a regular mortel probably will not touch.

Good Color and Bad Color. There is surely a better way to label those. The ‘Good Color’ is the color that is used in the HTML and KML output formats to indicate the track segments that correspond to valid positions. The ‘Bad Color’ is the color that is used to indicate segments with positions that were not selected. Example: when going through a tunnel, the device would log some invalid positions - invalid being no fix, PDOP to high, … (according to the filter settings). That part would be shown in the ‘Bad Color’.
When the Good color and the bad color are different, this results in bigger files and slower loading - especially for the HTML output.
I’ll need to write some kind of application note on the use of this.

‘Flash Settings’ corresponds to the settings stored in the internal flash of the device - not the flash used to log positions. These settings are the ones that are restored when the device lost power. Next to it is ‘NMEA Output Settings’. The values there after loss of power are the ones you can find in ‘Flash Settings’ (the ones that are absent will be 0). The ‘NMEA Outputs Settings’ are dynamic though : they can be changed and the value is maintained as long as the device has (backup) power.
I had added a tooltip to ‘Flash settings’, but apparently this is not good enough.

These settings are related only to the NMEA sentences sent by the Holux over the bluetooth connection. For example, GSA is used by GPS applications to get the sat positions, number in view and in use, and the position quality. The *DOP values are a good indication of the quality - the smaller the better. Some devices log ‘0.0’ when there is no fix, but this is not the case for MTK. Personally I log HDOP or PDOP, and the number of sattelites in view - but that has to be done through the ‘Log Format’.

I can add tooltips to the GLL, RMC, … buttons. to clarify.

Advanced filesettings:
a) NMEA File settings: this selects the sentences that are written to the ‘NMEA’ output file issued from log conversion.
b) GPX File settings:
i) Do not apply UTC offset: regardless of the UTC offset requested (‘Various’ in ‘Output Settings’) , do not apply this offset to GPX output. This way the GPS remains compliant with GPX specifications (the time is always UTC in GPX).
ii) Make a new track segment…: in stead of making a track appear as a continuous line, break it up in smaller tracksegments whenever a ‘bad position’ (according to filter) was detected.

The set button (Flash settings). The warning message says that it could brick your device. Most do not allow it anyways (Times Left = 0). This is to warn the user who is not really sure about what he is doing, while providing the ‘Advanced’ function to those that want it (and to show the actual settings).

Hi all,
I’ve bought a hullux m241 planning to use it for osm map creation. I was full of hope making precise paths with that device, because it offers a 3 meters precision.
In fact, when importing multiple traces from the same way, there is sometimes 40 meters of difference between the records. I didn’t understood why since I read that thread.
If I understand well, the GPS ship shows position (on the screen) with a «good» precision (±3 meters), but the log is 4 bytes less ? (4 for 8) Is it right ? I can’t beleive it !

I think I just have to put m241 on ebay to buy an other logger ? Or is there a replacement firmware available somewhere ? Or a trick to change the log precision ?


If you get ±40 meters you are not going to get a better position with another GPS unit, the Holux m-241 has submeter precision in the stored format. A ~$150 garmin will have a better antenna and chipset, but you can get 2-3 holuxs for that price…