Project Brief Edit

===Project Brief The Great Wireless Calculator Car Rally ===


Transferring information from one location to another has been one of the great technological advances of the 20th century, and wireless telecommunications is a current area of great industry interest. Once transmitted, generally information must be processed in order to be useful, e.g. receiving packets and displaying them in a web browser, or decoding a high definition digital TV transmission into pictures. In many cases this is done using microprocessors, among whose core functions is to perform simple arithmetic operations (using an arithmetic logic unit). This project involves the designing, building and testing of a system that will automatically receive a 2-bit binary number from physically spaced transmitters and add it to a 2-bit binary number pre-programmed using a DIP switch (supplied), as fast and accurately as possible. The operation of the transmitters will become clearer after your group has been issued with one in week 2. You are to design a system that will maximise the design objective function described below, and your mark in the final testing will depend on the extent to which you achieve this.


The design objective function (DOF) is given by the following equation: ISRAPDOF

Performance P (60% of final testing mark)

The performance of your system will be based on the time taken to complete the task and the accuracy 23015TNP−+= where N ≤ 2 is the number of bits correctly added and T is the time taken to complete the task (sec). Bonus marks may be available for systems that can successfully add larger binary numbers, however the marking scale may differ from that shown above. Project staff reserve the right to modify the above formula slightly based on the performance of the entire cohort of teams.19/03/2009

Robustness and Aesthetic appeal RA (10% of final testing mark) This will be subjectively determined based on criteria such as: how many times the system completes the task successfully, how the system would function if someone shook it slightly, and how much the system looks and performs like a product that a customer might buy. Bonus marks may be available for systems that (i) can negotiate a re-transmission if a transmission ‘fails’ and/or (ii) can operate accurately when significant noise is present.

Simplicity S (10% of final testing mark)

A simple design is almost always a good design and as a general rule this is determined by the total number of component parts that your design consists of. Simplicity is also related to the cost and ease with which it can be manufactured.

Innovation I (10% of final testing mark)

This will be subjectively determined by the panel of judges based on the uniqueness of your design in comparison to the other entries. In general this is related to the way in which you utilise technology to perform the primary functions of the design and the degree of difference between your solution and the other competitors. Bonus marks may be available for systems that can perform additional functionality (although these will be small if the core functionality is weak). It will be noted that the above marks add to a total of 90%. To achieve 100% for the design objective function DOF therefore requires the award of bonus marks.


The transmitter has three switches (looking at the front of the board):

§ Leftmost: This is the on/off switch, for conserving battery life § Middle: This sliding switch has three positions: “normal” (right), “test” (middle) and “fail/retransmit” (left). Except in the “test” position, the transmitter produces a sound only when activated by infrared light directed to one of the phototransistors. During the final testing, this transmitter switch will be in the “normal” position (except for groups attempting the retransmission problem). § Rightmost: This switch changes the state between a “0” and a “1”. You will notice that in the “1” state, the red LED is illuminated (unless the battery is flat!).

Transmitters will be physically located in a straight line on a level surface, all in the same orientation, as suggested by the photo in the slides of the first ElecEng project lecture. The distances between transmitters will be arbitrarily chosen, however these will probably be ≤ 1 metre. Vehicles can be aligned as needed at the starting position.


The DIP switch has four switches on it. The “ON” position (labelled) will correspond to a “1”, while the other position will represent a “0”. The switch labelled “1” will be the least significant bit, “2” will be the next most significant bit, etc. Similarly, the first transmitter (that the vehicle comes to) will be the least significant bit, the second 19/03/2009 transmitter will be the next most significant bit, etc.


No modification of the transmitters is permitted. Any materials may be considered for use. No toxic or dangerous materials however will be allowed. As a team you are restricted to spending no more than $100 for materials. If your system looks like it cost more than this to build, you will be asked to produce receipts. The system must operate autonomously (automatically), i.e. without any manual intervention, once the testing has commenced, and must be a single system, i.e. everything should be connected to and move with the vehicle. Use of remote controls is not permitted.

Possible Soluions Edit