Team Spot On!With

Zebulon ClarkDesireeAnd Earl

Team Sponsors

Computer Science and Information Systems

Meet Earl

And His Proud Parents

He uses the opto-interrupters of a mouse to keep track of how far he’s gone

The infrared sensors on his left side tell him how close he is to the wall, allow him to find openings and help him to stay on track.

Earl uses his ultrasonic sensor to decide how far away he is from the wall in front of him and if he

will be moving into the next grid or turning.

Earl relies on a SunSPOT that runs Java and sends commands to the PIC18F452 microcontroller .

The PIC handles the bump sensor, the odometers and sends commands to the motor

controller.

The motor controller receives commands from the PIC and controls the speed and direction of

the motors.

His 2 voltage regulators convert the battery voltage from 7.2 volts to both 5 and 6 volts, 6

for the motors and 5 for everything else.

Technologies Used

• Microchip PIC programmed in C using a procedural style

• SunSPOT programmed using OO principles

Urban Challenge Algorithm

• Earl uses a left-wall following algorithm• Earl is programmed to take advantage of

known properties of his environment such as the maze being setup on a 2’ x 2’ grid

• Earl also uses his bump sensor to recover from problems while navigating the maze

• Earl finds a 38kHz modulated IR and has the capability to hone in on it

Urban Challenge Algorithm

• Code explanation and style

Gold Rush Algorithm

• We are still working on the Gold Rush Algorithm

• The idea is to try to filter out all of the interference the sensors will receive perhaps relying on the bump sensors more and a slower changing weighted average on the sensors

• Earl will focus on homing in on the beacons and getting to them as fast as possible

Earl had Some Growing Pains

• Software guys doing hardware• Pesky IR sensors• Motors introducing noise to circuit• SPOT serial prior to blue SDK• Going straight using two motors

Successes and Lessons Learned

• Noisy circuits fixed, IR readings corrected• Successfully built a custom autonomous robot

of our own hardware and software design• Learned how to build a solid platform and

how important it is• Interfacing multiple devices is complicated• Running an algorithm in the face of noise and

in the presence of undetected errors is very hard

STOP!!