logo xcsoar logo xctracer


About XCSoar and XC Tracer

The current version of XCSoar (v6.8) contains no special driver for the XC Tracer Vario. However XCSoar and XCTracer interoperate very well if the driver "LXNAV" is selected in XCSoar and XC Tracer is configured to use the LXWP0 protocol. Based on my own experience this setup runs very stable and reliable.

However, the LXNAV driver is not tailor-made for the XC Tracer. For example it is not possible to display the battery level of the XC Tracer. Also for future expansions of the firmware it would be very inconvenient if there was no native driver. I have therefore written a driver for XCSoar which is tailored to the vario. The SW also contains an updated version of the Battery InfoBox.

XCSoar with drivers for XC Tracer

The driver for XC Tracer understands both the LXWP0 and the XCTRACER Sentences of XC Tracer. The battery level is only transmitted if XCTRACER is selected as the protocol. The protocol is selected by an entry in the file XCTRACER.TXT on the SD card of XCTracer.

Options are:

  • bluetoothProtocol=LXWP0

  • bluetoothProtocol=XCTRACER
    # XCTRACER already includes the GPS values, therefore set forwardGPSSentences to 'no'

To pair the XC and XC-Tracer-Soar, please perform the following steps:

  • Pairing via Bluetooth
    Android: Settings / Bluetooth / Paired devices
    KOBO: unfortunately no idea ...
  • In XCSoar: ""Config / Devices / Edit ": port "XC-Tracer" (or Bluetooth LE), "Driver XC Tracer Vario"
  • For the InfoBox in XCSoar: "Switch InfoBox", select "Battery" 


Enhanced  Battery InfoBox

In addition to the driver the SW also contains an updated version of the Battery InfoBox. The InfoBox not only displays the level of the main battery, but it also displays either the battery level or voltage of all connected devices that provide such information (e.g. BlueFly, FlyTec, CProbe, FlyNet , FlymasterF1 etc). The box cycles through the devices, going to the next one after ~7 seconds. The battery charge status is either displayed as a percentage vaule ("75%"), or as  a voltage ("5.7V"), depending on the information provided by the external device. The name of the device is shown in the lower part (the comment field) of the box.

To display the Info box: as usual tap long on an InfoBox, then "Switch InfoBox" and select "Battery".

If you want to check wheter your device currently provides battery information, please go to "Config / Devices". The status line for the devices A .. F now contains also the "battery" flag if availalble. This status line is also very helpful  in checking the connection status and information provide by a specific devices. As an example, for the XC Tracer it can show the following values:

Status Line   Explanation
Not connected   Guess what ...
Baro; Vario   Receiving Baro and Vario data, but no GPS Fixes and not battery info.
Typically this means that only data in the format LXWP0 is received. 
Make sure "forwardGPSSentences = yes" is configured,
and check that XCTracer receives a GPS signal.
GPS fix; Baro; Vario   Everything being received OK with the exception of the battery info.
You've probably configured the LXWP0 format, including forwardGPSSentences.
If you also want to see the battery level, please use the XCTRACER protocol.
GPS fix; Baro; Vario; Battery   Data is received in format XCTRACER.
Battery level of XC Tracer will be displayed in the Battery InfoBox.


Installation on  Android

  • Download the XCSoar_debug.apk file to your smartphone.
  • Allow "Settings / Device Management / Unknown sources" in your smartphone settings.
  • If another "official" test version of XCSoar is already installed, e.g. v6.8_beta2, then it must be uninstalled first:
    Search for  xcsoar icon red (the RED XCSoar) in "Settings/Apps", tap, then  "uninstall". 
    Otherwise, Android refuses to install the SW. Error message:
    "Application not installed. A package with the same name, but conflicting signature is already installed."
  • Go to your "Downloads" folder on the smartphone, select the XCSoar-debug.apk file, and run it. 
  • The SW is a test version, installs itself as "XCS-test" and can be used in parallel to an existing XCSoar installation. Caveat: do not confuse it with the offcial Beta 02, which has exactly the same name. In the splash screen of "my" version it says on the top left "XCSoar v6.8_beta2_TR3".
  • If you want to return to the  "official" v6.8_beta2 then please uninstall "my" version first. Otherwise you'll get the same error message as descrived above.

Installation on Kobo/Initializing the HM-10 Modul

The HM-10 or HM-11 Bluetooth Module on the Kobo must be initialized once before it will pair automatically with the XC-Tracer. This can be done via Telnet and the command line. Alternatively you can use the automated script  Bluetooth-HM10-Initialize. The script is not part of the XCSOAR Distribution and must be installed seperately, e.g. via USB copy. For more details please refer to readme.txt in the ZIP file. Many thanks to Tobias Boley for his great help with this script!


This table summarizes the recent test results. I would be very grateful if you provided me your experiences with the driver, so that I can broaden the test coverage and extend the table. Emails to  Diese E-Mail-Adresse ist vor Spambots geschützt! Zur Anzeige muss JavaScript eingeschaltet sein..

Device OS-Version Status
Sony Xperia Z Ultra Android 4.4.4 OK
Samsung Tab 4 Android OK
KOBO Mini / BLE HM-10  Linux OK



The SW builds are based on XCSoar v6.8_beta2. Meanwhile v6.8 fiinal has been relased, but the differences between the final 6.8 and  v6.8_beta2 are only marginal.



ANDROID XCSOAR 6.8_beta2 with  driver for XC Tracer

KOBO XCSOAR 6.8_beta2 with driver for XC Tracer.

THIS SW FOR KOBO STIL HAS VERY LIMITED TEST COVERAGE. So it's supposed to be used by very brave people only who know how to restore their Kobo to the previous state. Any volunteers ? 


Have fun flying with XCSoar and XC Tracer - but during the flight please do not play too much with xcsoar ;-)


XCSoar is Free Software released under the GNU/GPL License.
The source code of XCSoar is available at http://git.xcsoar.org/cgit/master/xcsoar.git/.
The source code of my changes is available at https://github.com/ThomasXBMC/XCSoar