A robot is a mechanical device, which possesses the capability of emulating a
human's characteristic in some way or another. The project is to build a mobile
robot, which should be able to avoid any encumbrances, while at the same time, is
capable of maneuvering at a predetermined path. The mobile robot should be
intelligent enough to make decisions as to which direction it is to turn when it
reaches a certain situation - ie. a turning point, a T-junction, a dead end, etc. An
extensive research would be conducted first before starting offdesigning the robot.
Subsequently, the exact materials would be selected. The structure of the mobile
robot would then be designed and built. The main circuitries required to construct a
mobile robot include ultrasonic sensors, a pair of H-bridge circuits, and a
microcontroller circuit. The ultrasonic sensors serve as eyes for the robot. They help
to detect obstacles en route. The purpose of constructing the H-bridge circuit is to
control the rotational direction of the motors. The microcontroller plays a most
essential role in the mobile robot. The microcontroller acts as a brain for the mobile
robot and would be making decisions on how the robot should react when it
encounter obstacles. Due to itssimplicity and the ease in getting familiarized with, an
8-bit PIC16F84A microcontroller is implemented for the project. The components -
that is, the sensors, motors, the H-bridge circuits, and the microcontroller, would be
validated individually first, before integrating them onto the mobile robot. The
program of the microcontroller would be written in assembly code form and would
then be validated. Lastly, successive validation tests would be conducted on the
entirerobot to ensurethe reliability ofthe mobilerobot
