1. Unit 1 - Introduction to VEX Robotics
Lesson 3 – Adding the Control Unit and Testing

2. Objectives for Today By the end of this lesson you will be able to:
Complete construction of the VEX Clawbot and add electrical wiring.
Add the control unit to the VEX Clawbot and use the joystick to test the robot.

3. Starter – Team Meeting!
As a team discuss what tasks you have completed so far and what you need to do in order to complete the construction of your robot.
Make a list of jobs to complete, showing who needs to do what and by when.
Job to be completed
By whom?
By when?

4. VEX Control Unit
The VEX Control Unit allows you to control the robot and make it perform different functions.
Think of it as the ‘brain’ of your robot.
The joystick sends infra-red signals to the control unit, thus allowing you to control the robot’s actions and movements.
VEX Control Unit
VEX Joystick

5. Adding the Control Unit and Wiring
Complete steps 1-27 of the instructions manual to finish construction of the Clawbot if not already done. Make sure motors etc are attached.
Follow Step 24 (page 14) to add the VEX Control Unit.
You must only add this when you are ready to test your robot as other groups will need it to test their Clawbots (1 per class).
Use the wiring diagram on pages 16 and 17 to connect the motor wires to the control unit and connect the battery.

6. Control Unit and Motor Wiring Diagram 1

7. Control Unit and Motor Wiring Diagram 2

8. Testing
Use the Joystick to check each motor works and the Clawbot moves backwards and forwards.
Move the grabber up and down – can you pick up a classroom object such as a pencil sharpener or rubber?
What to do if it doesn’t work?
If the robot does not work as expected try the following before asking your teacher for help:
Check all wiring is correct (are red, white and black wires connected to the right places on the control unit?).
Check all connections of motors.
Make sure nothing is blocking wheels etc.

9. Optional Programming Activity
Programming the robot will make it autonomous.
This means it is no longer reliant of human interaction and can perform actions for itself.
Sensors can also be added to add extra functionality. Visit the VEX Curriculum Website – Programming and Sensors for more information.
You will need to use RobotC, which is a drag and drop programming language designed specially for the VEX Cortex Microcontroller.

10. Extension Task & Homework
Next lesson you will be introduced to a design brief to create your own robot design to solve a problem faced by NASA.
Produce a page of research about NASA.
Your page should include the following:
Who are NASA and what do they do?
What sort of missions have NASA completed?
Show examples of robots that NASA have used in these missions and what they have used them for.
Find out what you can about the terrain and geography of the planet Mars – this will help you next lesson!