The diploma-thesis is describing the system for detecting objects at great distances, guidance and mapping spaces. It is also explaninig two different systems and their main advantages and disadvantages. Two basic systems differ due to the type of waves that are used for the detection of objects while their basic working principal is equal. It describes a complete ultrasonic system for object detection and mapping of spaces with all necessary hardware and software parts. The thesis gives description of the main pieces of code, their purpose and method of use. The system is based on the HC-SR04 ultrasonic sensor and Atmel's Atmega328 microprocessor that is used to initiate the transmission and signal detection, timing between the transmitted and the received signal, and calculation of the distance and the control of the platform's rotation.