The aim of this work is to make a device for measuring the coefficient of friction on a slope and a device for measuring the coefficient of friction between a pulley and a rope. Friction as it is present in all aspects of human life, allows movement, driving cars and various other vehicles, it is necessary to light a fire and it is necessary to make some connections and transmission of motion, so in the course of this paper will be mentioned more about friction . During the work, it will be defined what friction is, what kind of friction there is and the basic principles of how to solve problems when friction works will be defined (especially those along the slope and between the pulley and rope because that is the topic of this paper). In the theoretical part, the basic concepts related to friction will be defined and a description of individual components (IR sensors, Arduino, display...) that were needed to realize the design of the device and to make the device work. In the practical part of the paper, expressions for calculating the coefficient of friction on the slope and between the rope and the pulley will be defined, the device for measuring friction will be described and made, and an experiment of measuring the coefficient of friction will be performed and the results analyzed. Since the device works on the basis of Arduino microcontrollers and Arduino IDE software, part of the work will be dedicated to Arduino and a program that manages the device will be included. In the end, a conclusion will be made, ie a review of everything done so far and a review of this whole paper.