The Internet of Things and mixed reality are now among the most important areas in research or in practice. The aim of this paper is to propose an appropriate way of connection of these two areas, where is possible to control and monitor mechatronic devices using a mobile device with augmented/mixed reality support. The main task will be to explore these options in the area and implement this solution as prototype. The proposed methodology for control and diagnostics of mechatronic devices is modern as it combines hardware management, a Unity3D engine for mixed reality development, and communication within the Internet of Things network.