### Scribbler movements

```Scribbler Movements
Sec 9-3
Web Design
Objectives
The student will:
• Understand the basic movement commands
for the Scribbler
• Know how to create and execute a series of
commands
Scribbler Movements
• If you look at the scribbler from the bottom
you will notice that it has 3 wheels.
– The small wheel is for support only
– The large wheels are motorized. Each wheel has it
own motor.
– You can control each motor individually.
motors( Left, Right)
• Left and Right are in ranges from -1.0 to 1.0
• Negative numbers turn the motor backward
• 1.0 is the max speed of the motor. Think of the
numbers as % of total speed
Scribbler Movements - motors()
• Examples:
– motors(1.0, 1.0) – move forward
– motors(-1.0, -1.0) - move backward
– motors(1.0, 0) – tight circle to the right
– motors(1.0, -1.0) – spin (turn) to the right
• Note the action will continue until another
command (i.e. stop() ) is issued.
Scribbler Movements - motors()
• What do think will happen with the following
commands:
1. motors(0,0)
2. motors(1, 0.5)
3. motors(1, -0.5)
4. motors(.25, -.25)
Scribbler Movements
• Myro also provides built in functions for the
most common movements:
1. forward(speed)
2. backward(speed)
3. turnLeft(speed)
4. turnRight(speed)
5. Stop()
Scribbler Movements
• Another version of the commands accepts a
second argument (parameter) which is the
amount of time in seconds.
1. forward(SPEED, SECONDS)
2. backward(SPEED, SECONDS)
3. turnLeft(SPEED, SECONDS)
4. turnRight(SPEED, SECONDS)
Draw a Square
• There is no way to tell
forward(1, 1)
the robot to move 5
turnLeft(1, .29)
feet or to turn right 90o
forward(1, 1)
• For Bucky .29 works
turnLeft(1, .29)
the best for the turn
forward(1, 1)
but that might not be
turnLeft(1, .29)
forward(1, 1)
turnLeft(1, .29)
Translate and Rotate
• translate(speed) moves the robot forward
or back.
• rotate(speed) turns the robot left.
• move(TRANSLATE_SPEED, ROTATE_SPEED)
will perform a translate and rotate at the
same time. The result will be a circle.
Executing a Series of Commands
• If you would like to type a series of commands
and have them executed all at once then you
can…
1. Open a new window:
2. Type in the commands
3. Save the file
4. Run the module:
IDLE Tips – Command History
• You can repeat a previous command by using
IDLE's command history feature:
– ALT‐p retrieves previous command
– ALT‐n retrieves next
– You can also click your cursor on any previous
command and press ALT‐ENTER to repeat that
command.
Summary
• Many different ways to move your robot.
– motors(), forward(), backward(),
turnLeft(), turnRight(), move(),
stop(), etc.
• You can type in a series of commands, save
them and then have the IDLE shell execute
those commands.
Rest of Today
• Experiment with your robot to make a octogon:
• Make the side a movement of 0.5 seconds (keep
the octagon small).
• The robot should end up roughly where it started
and facing the same direction as when it started.
• Once you have the commands that make a
octagon, show it to me.
• Read pages 21-26 in Learning Computing with
Robots.
```