The prototype of the FreeVario V2.0 is ready. Now there are a few more test flights to follow, then the new hardware version will be available to buy in the web shop. Of course, all the necessary files for self-build will be published again. However, building it yourself is much more complex than before and is not necessarily recommended. It takes significantly less effort to order the kit, or at least the assembled circuit boards.

The FreeVario V2.0 has the following innovations:
– the socket for updating the ESP32 is now a USB-C socket
– There is only one socket, so both ESP32 can be updated with. Which one is currently selected to update can be choose using a slide switch
– the external speaker is connected with a 3.5mm jack plug
– the sound is no longer generated by a sine wave generator, but by the sound ESP
– the background noise at low volume is eliminated
– high-quality voltage converters for 3.3V or 5V
– Both ESP32 are no longer used as a dev board, but are soldered on as a chip

!!Update Service!!

With the software update V2.0, both the average and the current external wind and their speeds are displayed in the FreeVario. You can see what it looks like in the picture gallery. The external wind can be supplied, for example, by the Larus, Anemoi or comparable devices. If the external wind is not available, the one calculated by XCSoar is displayed. The function can be activated or deactivated in the menu. The update to version 2.0 is a little more complicated because you may not only have to exchange the image via the web interface, but also update the data folders of the two boards. We offer you a suitable service in the shop: Update Service

We are happy that you are interested in our FreeVario project.

Here is a brief overview of the FreeVario project. It is an open source E-Variometer which works together with the software XCSoar. The primary focus was on the development of a device that serves as a supplement to the OpenVario system (open source glider computer based on XCSoar:

The project of the E-Variometer comes from the XCSoar Forum, but was not completed. Dirk therefore took up the project in autumn 2019 to develop it into a functional variometer. Over the course of time, various functions were expanded, converted and rebuilt. Sascha joined in February 2020 and helped to develop software and driver programming for XCSoar. After a few attempts and changes of hardware and software, a functional prototype was completed in May 2020. With creative ideas, some great functions could be accommodated in the variometer. This includes menu control and the option to transfer and use settings from the variometer directly to XCSoar. Just have a look at the short introductory videos and pictures to get an impression of the variometer.

The FreeVario has been designed to generate the vario sound itself. This arose from the fact that the old OpenVario image could only issue the vario sound and not XCSoar warnings at the same time. With the new image of OpenVario it is possible to issue the vario sound and the XCSoar warnings. It is therefore no longer absolutely necessary to provide the FreeVario with a loudspeaker. Everyone can decide to build the FreeVario with the loudspeaker, and then to deactivate variod in OpenVario, or to omit the loudspeaker in FreeVario, and not to deactivate variod in OpenVario. So if you don’t like our sound, you can still use the OpenVario sound.

On this project page you will soon receive all the information you need to build the variometer and install the software. We hope you enjoy this project and we look forward to any feedback on the project.

Important to know: XCSoar is the prerequisite for operating the variometer, it is not a standalone device. Basically, however, it can be operated with any hardware that runs XCSoar and that can deliver data quickly enough via a serial interface. So it’s basically not limited to OpenVario!

Presentation of our projects at the German Glider Pilot Day 2023 in Freudenstadt. Thank you Christian for allowing me to use the video!