The aim of this Bachelor's thesis was to build a small robot unit which can receive a control signal from a battery state indicator circuit, when the battery voltage drops below pre-defined limit. This changes the robot's behaviour according to the battery's state. The low-voltage behaviour activates the IR-sensor, which the robot can use to detect a black line on the ground and for example follow it to a re-charging platform.

The school's curriculum included Linux- C- and microcontroller programming, but courses for mechanics and electronics were few. Although the primary aim was to build a functional robot unit, the additional hardware and other components were designed as energy efficient and compact as possible.

Like the robot of Mikkonen and Härkönen, this one also works as a template for further development of new solutions by offering different ways of approach. The behaviour programming of the robot was designed to work with a small PC-terminal, and thus the project supports not only object-oriented programming, but also the practical design and development of hardware and software applications. For further development I would suggest a re-charging platform, and a USB-based solution to replace the parallel port programming.

This document focused on building the operating system and programmes, sensor mounting and building the printed circuit boards. The result is a simple, self-sufficient unit.