We present a low-cost, fully computer-controlled, Arduino-based, educational laboratory (SolarInsight) to be used in undergraduate university courses concerned with electrical engineering and physics. The major goal of the system is to provide students with the necessary instrumentation, software tools and methodology in order to learn fundamental concepts of semiconductor physics by exploring the process of an experimental physics inquiry. The system runs under the Windows operating system and is composed of a data acquisition/control board, a power supply and processing boards, sensing elements, a graphical user interface and data analysis software. The data acquisition/control board is based on the Arduino open source electronics prototyping platform. The graphical user interface and communication with the Arduino are developed in C# and C++ programming languages respectively, by using IDE Microsoft Visual Studio 2010 Professional, which is freely available to students. Finally, the data analysis is performed by using the open source, object-oriented framework ROOT. Currently the system supports five teaching activities, each one corresponding to an independent tab in the user interface. SolarInsight has been partially developed in the context of a diploma thesis conducted within the Technological Educational Institute of Piraeus under the co-supervision of the Physics and Electronic Computer Systems departments' academic staff. (Contains 8 figures.)