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Read rotation from motor

Add-On Required: This feature requires the MATLAB Support Package for LEGO MINDSTORMS EV3 Hardware add-on.



rotation = readRotation(mymotor) reads the total amount of rotation since the creation of the connection to the motor, and returns the measurement in degrees. You can use the resetRotation function to reset this value to zero.


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Control a motor, measure the wheel rotation of the motor in degrees, and clear the measurement.

Create a connection to the EV3 brick called myev3.

myev3 = legoev3
myev3 = 

  legoev3 with properties:

      FirmwareVersion: 'V1.03E'
           HardwareID: []
            IPAddress: []
    CommunicationType: 'USB'
         BatteryLevel: 100
     ConnectedSensors: {'touch'  'gyro'  'color'  'sonic'}

The sensor appears in the list of connected sensors.

Create a connection to a motor. Specify the letter of the EV3 output port that connects to the motor.

mymotor = motor(myev3,'A')
mymotor = 

  motor with properties:

    OutputPort: 'A'
         Speed: 0

By default, the speed is zero.

Configure the motor to reverse at half speed.

mymotor.Speed = -50
mymotor = 

  motor with properties:

    OutputPort: 'A'
         Speed: -50

Start the motor.


Read the rotation value, in degrees, of the motor.

rotation = readRotation(mymotor)
ans =


Reset the rotation value of the motor to zero.


Input Arguments

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Connection to a motor, specified as a string that represents the object created using motor.

Example: mymotor

Data Types: char

Output Arguments

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Rotation of motor in degrees, returned as an int32 value. Creating a connection to a motor initializes this value to zero. To reset this value to zero, use resetRotation.