The SFA Rover

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The SFA Rover

• Team Project

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The SFA Rover

• Must be demonstrated at the beginning of the last
  lab of the semester, Dec 11th.
• 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.

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Background

• This project has been a part of the electronics
  course since 1999.
• In the past we have used DC motors or PC fans.

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Background

• Modifications have been inspired by a Randys SFA
  Rover.
• This is Thursdays seminar topic.

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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.

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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.

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The Vehicle Course
6-feet
50-feet
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The Vehicle Course
6-feet
50-feet
Extra Credit
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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.

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

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Key Concepts

• Other key ideas used in this team project
  include
• Battery Power Management
• Torque
• Friction
• Gearboxes

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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.

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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.

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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.

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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.