Programming a MotorBy Joshua Shaw
We have previously added a While Loop We are now going to use it for programming
the robot
From the last Power Point
3
Inside the While Loop a set of brackets appear, this is where we will create the program
First lets add a motor to the program◦ Since motor outlets “1” and “10” are not permitted
for use in competition, we will not use them in the program
Click the “+” beside Joystick under the Function Blocks
Click and drag the Joystick To Motor function to the vertical line between the brackets in your While Loop
When you do this, a dialog box appears
Add a Motor
4
The Joystick to Motor dialog box should look like this
However, we can not use Motor 1 in the competition◦ For this example we
will use Motor 2◦ We do this by clicking
on the down arrow in the motor box and select Motor 2
Motor Programming
5
A Transmitter Channel allows you to select which buttons or joysticks on the Joystick Controller you want to use for a specific purpose◦ In this program we are going to use the left hand joystick to
operate the wheels and the right hand joystick to operate an arm and a claw
We can also change the Channel the same way as we changed the Motor◦ For this example we will use Channel 1◦ Which just so happens to be the default◦ Finally click Ok
You can create as many motor programs as you need for your program.◦ But lets keep this one simple
Transmitter Channel
6
We will now create a motor program that operates with buttons instead of the joystick
Go to the Function Block Under the Joystick folder Click and drag the Joystick Digital to
Motor onto the vertical line between the bracket boxes in the While Loop
Motor Controlled by Buttons
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The program for the motor in this example will look similar to the default
The difference is that the Motor # will be “5” and not “2”
Change the number by clicking on the down arrow
Then click on the “5” Lets change the Channel
to “6” the same way we changed the Motor #
Motor Controlled by buttons cont’d
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The final program for the motor will look like this
Finally click OK
Completed Motor Controlled by Buttons Program
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Using the Joystick Controller – Channel 6 You will use the
Channel 6 on the Joystick Controller
Push the top right button to move the motor to the left
Push the bottom right button to move the motor to the right
When you let off of the button the motor will slow down and stop
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Test the Program Again Before we move any farther it is best to save
the program.◦ It is also good to save it on a mobile hard drive◦ This gives the advantage to access the program on
another computer that has Easy C Now lets test the robot Download the program to the Cortex. You can
refer back to the downloading procedure illustrated in slide thirteen thru slide seventeen
Now test the program. slide eighteen
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The downside to using this program, which enables the buttons to control the motor, is that you can not vary the speed of the motor◦ The motors speed remains constant at all times
The first program that we created with a motor, which was controlled by a joystick, allows you to control the speed of the motor◦ It is known as an analog program
Analog -vs- Digital Programming
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As you have probably notice, the motors of your robot give off a high pitch whining sound
This is due to the slight push on the joysticks from any number of forces◦ Slight breeze◦ Gravity◦ Slight push from the fingers
It is able to be fixed fairly easily
Noise Pollution
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Go back to the Function Block Go to the Joystick commands Drag and drop the Joystick Analog
Deadband between the Variable box and the While box
Since we have a motor that is controlled by Channel 1 on the Joystick Controller. We will reduce the noise of this motor by setting the Analog Channel # to “1”
Set both the Positive Deadband and Negative Deadband to “20”
Reducing Noise for Channel 1 Motor
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The program should look like this
Push OK Now do this as may
times as needed In this example we need
three of these programs because we have three motors
Each motor requires one of these programs to keep the noise down
Completed Deadband Program
The next PowerPoint is Programming a Servo
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