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Topics Covered

  • TurnRight Command Block

    • Lesson Links

    ... ...
    Check Your Understanding:
    1. 1. What does the robot do when the TurnRight program is run?
      2. Moves straight forward
      Spins to the right without moving forward at all
      Locks the right wheel in place and run the left wheel forward
      Turns the robot completely around 1 time
    2. 2. True or False: With "Rotations" on the TurnRight Command Block to 1, the whole robot rotates 1 time.
      3. True: the robot will turn around 1 time
      False: the wheels will turn 1 time, not the body
    Try It!
    Try it! 1

    Direction of Turn

    Using the turnRight command block makes the robot turn to the right, in place. What happens if you use the turnLeft command instead? Try it!
    Virtual Robot TurnLeftVR.rbg Physical Robot TurnLeft.rbg

    What happens?
    The robot turns in place to the left!
    1. 1. How much did the robot's wheel turn during this movement?
      2. 1 rotation
      1 degree
      Enough to make the robot spin completely around one time
      One lap around the table
    2. 2. What does the "1 rotation" refer to in the turnLeft Command Block controls?
      3. 1 full rotation of the robot's body during a turn
      1 rotation of the robot's wheels
      1 time that the robot is picked up and turned around
      One rotation of the Earth around its axis
    Try it! 2

    Units of Turn

    What happens if you switch the second box of the turnLeft or turnRight command from Rotations to Degrees? Try it!
    Virtual Robot TurnDegreesVR.rbg Physical Robot TurnDegrees.rbg

    What happens?
    The robot barely moves when it’s set to move 1 Degree! There are 360 degrees in one rotation of the motor, so it barely moves.
    From the change you made above, change the value in the first box from 1 to 270. Try it!

    What happens?
    The motors turn ¾ of a rotation, making the robot turn much further.
    Using degrees as your units gives you greater control over the robots turns!
    1. 1. How much did the robot's wheel turn during this movement?
      2. 270 rotations
      2.7 rotations
      3/4 of a rotation
      It didn't move
    2. 2. Why would you use Degrees instead of Rotations?
      3. If you are turning in reverse
      If you're using a temperature sensor to control movement
      For greater control over the robot's turns
      You wouldn't
    Mini Challenge

    Mini Challenge 1: 90 Degree Turn Challenge

    Program your robot to turn exactly 90 degrees to its right!
    Virtual Robot 90DegTurnVR.rbg Physical Robot 90DegTurn.rbg
    • Place two pieces of tape so they form 90 degree angles.
    • Place your robot so it faces along one piece of tape, and program it so that it turns to face directly along the next piece.

    Change the amount your robot turns by changing the number of Rotations it is programmed to go.

    Measure how far your robot turned with its 1 rotation program, and see if you can use that information to reason about how many rotations is should take to turn 90 degrees instead!

    + hint
    Did You Notice?

    Did you notice?

    Wheels and Turning
    All your robot's movement is based on the way in which its two motors move.
    The motion you get is determined by using different combinations of powers on those motors.
    If both motors go forward, the robot moves straight forward.
    If both motors run backward, the robot moves straight backward.
    If they run in opposite directions, they robot spins in place.
    If the left side moves forward while the right moves back, the robot spins to the right.
    If the right side moves forward while the left moves back, the robot spins to the left.
    Next
    Copyright(c)2012 Carnegie Mellon Robotics Academy. All rights reserved.