The primary purpose of the thesis was to design a hands- on course on a real-time operating system (RTOS). The course structure was developed based on Boli Gao’s paper – “Design of RTOS Teaching Environment.”. The course focuses on the most basic concepts of RTOS, such as pre-emptive scheduling, semaphore, priority inversion, mutex, event flag, and message queue. Besides that, sensors and an OLED display were added to exercises to understand better how to implement external components to an RTOS project. The teaching environment was constructed by implementing μC/OS-III on the STM32 Nucleo L152RE development board, which has an ARM Cortex-M3 processor. The development tools and software used to create exercises, instructions, and documentation were Visual Studio Code, PlatformIO, STM32CubeMX, Doxygen, and Fritzing.