Stang Positioning System (StangPS) is a circuit that uses a Motorola HC08GP32 microprocessor to keep track of the position and orientation of the robot. The circuit uses data from three types of external sensors in its calculations: Light sensors, Potentiometers, and a Gyro sensor.

Two light sensors are mounted to a slotted wheel such that they are 90 degrees out of phase. This allows the microprocessor to know how much the wheel turns along with which direction the wheel is turning. This data gives us the distance that the robot has traveled. Distance is known to within 2 inches.

The gyro sensor is mounted such that it measures the rate of lateral rotation. This data is integrated and processed to give the orientation of the robot, or the angle that the frame of the robot is relative to the field. The potentiometers measure the angle that the crab wheels are at relative to the robot.

Combining the gyro and potentiometer data yields a true heading, the angle relative to the field that the robot is moving.

Combining all three pieces of data allows the microprocessor to create a coordinate on the field that the robot is located.

StangPS communicates with the robot controller via the serial interface of the programming port of the RC. The robot controller sends requests for data and the microcontroller responds with the three pieces of data.