Draft System Specification

Principle of Operation

A block diagram for an auto-mechanical chess board (refer to Figure A), can be divided into four primary categories: power, user interface, motor control, and logic unit. The lines indicate data and power transfer from section to section.

The intent of this design is to utilize multiple AVR chip to completely control the movements of a magnet, the magnet will control the movement of the chess pieces as the game is played. It will also incorporate error detection programming. Most of these functions will be performed in software.

The principle of operation is to allow for auto-mechanical game play. The players will input SAN notation into a keypad to move the pieces around the board. The game will move the pieces using magnets on the bottom of the board and take any killed pieces to a graveyard area. The game will automatically detect errors such as illegal chess moves, piece movement errors, etc... Game status will be indicated by a display connected to the two keypads provided for each user. The game will also incorporate a single player “training mode” which will allow the player to play against an AI opponent programmed into the AVR chips.

Fig 1.1 Block Diagram

The game begins to function upon plugging the power cord in and hitting the power button on the board. Keypad 2 will then need to be set to the appropriate player type prior to a reset/game start button that will be hit to start the game. The choice of player type on the keypad will be ‘AI’ or ‘Human Opponent.’ The game is not designed for two AI players, therefore, only one of the keypads will have the AI setting available.

All movements are stored by the system in external memory to allow for error detection of game such as illegal moves as well as game status such as checkmate. Error detection is apart of the software programming within the logical unit as well as control for game status updates, user interface signal control, and motor/magnet control.

Game updates are displayed in two methods. The user interface will have a display that will indicate to the players what move they are entering as well as if it is legal or illegal. Colored LEDs will indicate to players the status of the game that must be resolved such as checkmate, stalemate, etc...

The electromagnets and motors handle movement of the chess pieces. Motors move the worm gears, which move the magnets in the X and Y plane. Dual magnets are used to allow for dual piece movement in the event that a piece needs to be moved and another one needs to be killed; this eliminates an extra movement which would have been required due to the piece that is being killed needing to be moved to the graveyard.

Specification of the Blocks:
The block diagram is show in Fig 1.1 and shows control signals, physical components as well as the more abstract components. Solid blocks are the physical components while the dotted lines are representative of the components within them that help to control them. Lines and arrows indicate signals and which direction they need to flow.

The user interface consists of two keypads and two displays, one for each player in a two-player mode. Only one of the keypads and displays will be used in the event that a player chooses to play against the built in AI. Moves are inputted into the keypad that will display whether the moves are legal or illegal. If the moves are illegal, a message on the display will inform the player that the move is not allowed. If the move is legal, the commands will be passed onto the logical unit which will process the commands.

The logical unit handles the controls of the entire system. Software for this will be programmed in C onto AVR chips. It takes user input from the user interface keypad and sends output to the display when needed. It also handles error detection and processing of moves. All moves are stored in external memory for use in error detection and to check for move validity since it will be necessary to know what piece is where to determine how they will move. Error detection checks for game play problems as well as hardware problems that involve moving the pieces.

The magnets are connected to worm gears that are moved to the appropriate positions by step motors. While the magnets are moved by the worm gears, the worm gears and magnet controls are still handled by the logical unit which detects how best to move the pieces from its starting location to its destination.

If power is pulled from the system, the game will not retain its information about the movements and the game will have to be restarted. If a game ends or a reset/restart is desired, the game reset button will have to be hit and the pieces will have to manually be setup in their starting locations. Power to the system can also be turned off by flipping the power switch.

 

Last Updated: 11/19/05