This study concerns the development of an optical compass inspired by the celestial compass of the desert ant Cataglyphis. This bioinspired navigational instrument opens up new opportunities for navigation in the absence of GNSS or GSM coverage for locating outdoors. This pedagogical activity, through the design of the instrument, aims at understand different physical phenomena involved in optical heading detection: Rayleigh scattering of sunlight in the sky, polarization of light and measurement of heading from photosensors. The design and the fabrication of an experimental teaching device are both described. Experiments were performed to allow students (2nd year of master in robotics & IoT) to become familiar with bio-inspired engineering applied to optical heading detection. Students used an Arduino board (8-bit architecture) to address issues related to the real-time processing of microcontroller with limited computational capabilities. Finally, examples of measurements made by students are presented to demonstrate the pedagogical use of such an experimental device for heading measurement in robotics. Our prototype works in the blue visible light and has only 4 photosensors, each one covered with a different orientation of its polarizing filter.