The purpose of this project is to produce a narrative description of the design and construction of a microcontroller based dot matrix advert display. Firstly computer aided design is the modeling of physical system on Computers allowing both interactive and automatic analysis of design variant and the expression of design in a form suitable for manufacturing. This follows by explaining the microcontroller based dot matrix advert display as a device which is fast gaining wide acceptance and application in the present days due to its ability to provide a very high precision timing. The dot matrix advert display can be describe as an electro-mechanical  system for processing information in which the information is represented by physical quantities, which are so constrained to take only discrete values that can be referred to as binary signals.