This format can...
The Holux m241 is a small datalogger using the MTK chipset, with a couple small differences in the binary format. In its default configuration, it can store ~100000 trackpoints with very limited data; to configure extended logging you can use the BT747 open source software bt747 Waypoint storage is possible only if "recording reason" (RCR) is enabled in the settings.
The m-241 came in two models. The yellow one, popular with photographers, internally used the Silicon Labs CP210X chipset to transform the internal and inaccessible serial port to the USB port that was familiar on the side. The drivers for that port can be found with SiLabs CP210x serial port drivers. The red and white one existed very briefly before Holux went out of business. GPSBabel does not work with the red and white one.
Holux GPSport 245 is a datalogger with display suitable for cycling, walking and running. It can store ~200k trackpoints with limited data. The m241 and m241-bin format is able to automatically detect GPSport 245 data and handle the differences from Holux 241 devices. Note: GP245 does not log any quality of the position.
Use the m241 format to connect with the unit serially and m241-bin to read files saved by the device.
This module is also reported to handle the Holux M1000c.
Most of the loggers cannot receive bluetooth commands, they can only send data. Since GPSBabel needs to send commands to the GPS device it won't work. Download the data using the USB cable instead.
Erase device data after download.
This option erases the track log from the device after download.
Only erase device data, do not download anything.
This option will only erase the logger data. No data is downloaded.
This option is typically used as a second step after the data has been downloaded and verified.
Enable logging after download.
This option will enable the logger after download.
By default the logger is re-enabled when download is finished if previously were enabled. But if the download is aborted or failed the log functionality won't be enabled again.
MTK compatible CSV output file.
Note that this option is a bit of an oddity in the GPSBabel arsenal. This should probably be a "real" output type of its own instead of being bolted onto an input type.