The SFA Rover Team Project

The SFA Rover  Must be demonstrated at the beginning of the last lab of the semester, Dec 11 th.  Teams can work on this project after the normal labs are complete each week.  Additional team meetings outside of the normal class time may be required.

Background  This project has been a part of the electronics course since  In the past we have used DC motors or PC fans.

Background  Modifications have been inspired by a Randy’s SFA Rover.  This is Thursday’s seminar topic.

Project Update  In the past the vehicles were built by individuals and had to travel 50-feet in a short time.  Now the vehicle project is a team project and each vehicle must avoid obstacles and travel 50 feet in 10 minutes.

A Robot with a Brain  Each vehicle will have a programmable integrated circuit (PIC) that will make decision and control the motors automatically.  This kind of robot control is the same kind of control that is used on Mars robot rovers.

The Vehicle Course 50-feet 6-feet

The Vehicle Course 50-feet 6-feet Extra Credit

Scoring D = Distance traveled in feet in 10 minutes (the maximum distance is 50-feet) R = 15 if the vehicle successfully demonstrates avoiding an obstacle on the right and 0 if it is not demonstrated L = 15 if the vehicle successfully demonstrates avoiding an obstacle on the left and 0 if it is not demonstrated T = -10 each time the vehicle is touched by a team member during the course Grade = T + L + R + D × 70/(50ft) Bonus: For each extra left or right obstacle avoided, 2 points of extra credit will be earned for each member of the team. A maximum of 20 extra points can be earned in this manner.

Left Button Right Button PIC Microcontroller H-Bridge 9-Volt Battery Right Motor Left Motor Voltage Regulator SFA Rover Circuit Diagram

Key Concepts Note that the parts used in the team project are discussed in your text book. Chapter 7 - Logic Circuits Chapter 8 - Microcomputers Chapter 10 - Diodes (Voltage Regulator) Chapter 12 - Transistors (H-Bridge) Chapter 16 - DC Machines (Motors)

Key Concepts Other key ideas used in this team project include: Battery Power Management Torque Friction Gearboxes

Beginning the Construction  There should be 4 members on each team.  Two team members will now work on together on one Heathkit Digital Experimenter.  In pairs take one motor and connect it between 0 and 5 Volts.  Do not supply more than 5 Volts.  Reverse the wires and notice that the motors rotates in the opposite direction.

Beginning the Construction  Turn off the power. Now connect the motors to the H-Bridge chip.  Use two Data Switches as inputs into the H-Bridge that can be used to change the direction of the motors. **  Make notes about your wiring so that you can reconstruct this circuit on a portable breadboard later.

More Construction  Now use the parts provided to construct a chassis for your vehicle.  If time permits, move you H-Bridge to a portable breadboard and power it using a voltage regulator and 9-Volt battery.  If you are successful, then try to run your vehicle straight down the course.

To be continued…  If you did not complete the course, then use some lab time this week to modify your vehicle until it can complete the 50- foot course.  We will integrate the PIC microcontroller and buttons into the circuit later. This will allow the vehicles to avoid obstacles.