Windsond is part of a project by the Swedish university KTH to launch a high-altitude balloon and measure muon radiation.
Windsond is attached to the bigger payload to assist with live position tracking and data telemetry, onboard logging and eventual payload recovery. Windsond interfaces with the custom muon sensor by the newly developed external i2c interface.

The launch can be followed live (in Swedish) at this link:
http://www.vetenskapenshus.se/fluxlite-3-h%C3%B6gh%C3%B6jdsballongen

Good luck with the project!

UPDATE:
The balloon reached almost 35km and the equipment was successfully recovered by the team.