This thesis addresses the development, implementation and calibration of the sun sensors used in the UWE-4 satellite which is a CubeSat built by the University of Würzburg. It has several sensors for determining the attitude in space including six digital sun sensors. The chosen sun sensor is a miniature pinhole camera called "NanEye" by AWAIBA with a footprint size of about 1x1 mm. At first a short overview of the state of the art of digital sun sensors and the UWE-4 satellite are given. A concept based on traditional camera calibration methods is developed and implemented for calibrating one sun sensor, which can be enhanced for calibrating multiple sun sensors at once, described in the outlook. The calibration procedure utilizes a method of having the camera sensing a single fixed artificial sun as reference point at many different orientations and thus acquiring enough data to refine camera models and further possibilities of modelling errors. Applying the calibration on the NanEye yielded accuracies of about less than 0.5 deg for the pinhole camera model considering radial distortion, and less than 0.3 deg for the used fisheye camera model (RMS-values). Further the problem of efficiently handing over the sun detecting task between all sun sensors during sun tracking is addressed. In the third part an energy controller, monitoring and controlling the energy consumption of the UWE-4 sun vector sampling device by actively changing the clock speeds of the used microcontroller is developed and implemented. To test the applicability of the developed concepts several experiments were performed and the results evaluated.