One important sensor for the function of the Sunchronizer is the BMI160 acceleration sensor. 

To ensure that the SolarPanel is always perfectly aligned with the sun, the elevation angle of the panel is regularly measured and adjusted accordingly thanks to the BMI160. 

Thanks to the housing shown, the BMI160 can be mounted splash-proof on the support profile, which later also holds the solar panel. 

The STLs for the housing can be found on my blog at: https://nerdiy.de/en/product-2/bmi160-modul-gehaeuse-3d-druckbar-stl-dateien/