The OpenDrone itself is straight outta 3D printer. The flight controller, a raspberry-pi in our case, is developed in Visual Studio with C++. The OS is Raspbian Stretch Lite. For collision-avoiding we will use some ultrasonic sensors on every side of the drone. After calculating, the flight controller is fed with the calculated results. The whole drone is controlled with an Android App. In the App, you can set different markers on a map where, after the markers been set, the drone will autonomously fly to. If you want you can fly manually, too.