The purpose of the work described in this paper is to compare more configurations belonging to portables real-time operating systems for embedded devices based on Raspberry Pi board. The developed application in this work can monitor the status in a greenhouse: irrigation, heating, ventilation, humidification, closing/opening panels etc. following weather conditions. Our target is to choose an efficient, minimal operating system optimized for the desired application. Other targets are high flexibility, optimal modularity, high readability and maintainability of the source code.