The little electromechanical mouse to the left was proudly constructed by Mark Bezdany and myself as our senior design project. Its code name was Jerry, named after the cartoon character in Tom & Jerry. The mouse had the ability to traverse a 6x6 maze given the starting and ending destination and the starting direction. Once started, Jerry would either stop at the desired destination node or traverse the entire maze and stop after realizing that there was no physical path to the destination node.
To navigate through the maze the mouse used optoelectronic sensors on its bottom as shown in the picture to the left. This told Jerry were he was at all times. Valid nodes and paths had reflective tape the on tops of them. The rail in the center of the maze helped in guiding Jerry to its next node. The processor we chose was the Motorola 68HC11EVB. Four D cell batteries controlled Jerry's circuitry and processor boards. While another four D cell batteries were used to control the motor. The seperation of powers helped to reduce any noise and let us power on only the portion of the mouse that we needed.
For control purposes we used three switches, shown in the left hand side of the picture. One switch controlled power to the processor board and circuitry. Another controlled power to the motors. This allowed us to debug certain aspects of the design without turning on the entire mouse. The last switch was the control switch for the entire system. This switch allowed us to stop Jerry while it was traversing the maze to make any minor repairs needed. Once the repairs were made we could place Jerry were we stopped him, flip the control switch to ON and it would continue from the very same spot. The LED's emitted the current output of the sensors, this aided in debugging.
The board that Jerry navigated on was hardwood with peg board below it. The peg board allowed us to make the maze reconfigurable. Therefore, you were not limited to a single maze, in any way other than size. We had fun creating new mazes and testing Jerry's ability.