In my thesis I set the goal to design and implement a ball balancing plate system. The thesis describes the mechanical model of the ball and plate relation, the construction of the ball and plate system, the design and implementation of the digital controller. In my solution the position of the ball is detected by a web camera using colour based image processing, implemented in PROCESSING environment. The necessary geometrical parameters for the controller and the control signal are also calculated in PROCESSING. The control signal is sent with serial communication to Arduino ATmega 2560 microcontroller, which generates a PWM signal from it. The PWM signal is sent to the servo motors to control them to the right angle. The digital control is implemented by a PID controller, which is able to settle the ball to the desired position on the plate with slight error when the parameters are tuned properly. The thesis presents the mathematical model and the MATLAB/Simulink simulation of the system. The measurements, when the ball settles to a given reference point and when the ball follows a predefined shape, can be found in the end of the thesis. Also videos were recorded to illustrate the operation of the system. The thesis ends with the conclusion and possible future improvements.