Answer Key: EV3 Test Circuits (Port View) Worksheet Answer Key

Answer Key: View Mode Worksheet

1. Touch Sensor

  •  The display changes from “0” to “1” when the touch sensor is pressed.
  •  The“1” represents the touch sensor is pressed (switch closed) and the “0” not pressed (switch open).

2. Color Sensor

  • The red LED illuminates in Reflected Light mode ('Col-Reflect') and the display shows a value as a percentage.
    • The value represents the amount of light reflecting back to the sensor.
    •  As the sensor approaches a surface, the amount of reflected light increases, however, once the sensor touches the surface the value can decrease again due to the plastic divider between the LED and sensor.
  • In Ambient Light mode ('Col - Ambient') the LED is turned off and the display shows a value as a percentage.
    • The value represents the amount of light striking the sensor.
    •   Ambient Light mode uses the light that is naturally in the environment, Reflected Light mode adds its own light with the LED.
  • In Color mode ('Col - Color'), the Color Sensor recognizes seven colors - black, blue, green, yellow, red, white, and brown - plus No Color. An object that is not one of these colors may be detected as “No Color”, or it may be detected as a similar color. For example, an orange object might be detected as red or yellow, depending on how much red the orange has in it, or as brown or black if the orange is very dark or too far away from the sensor.
    • When the Color Sensor is in Color mode, red, green, and blue LED lights on the front of the sensor will turn on.
    • Results from Color Sensor: (0) - no color, (1) - black, (2) - blue, (3) - green, (4) - yellow, (5) - red, (6) - white, (7) - brown.

3. Ultrasonic Sensor

  • Us-Dist-In mode - display shows a value in inches indicating how far away the sensor is from an object (note: the sensor is some distance inside the plastic housing, so the distance displayed is a little further than the front of the sensor).
    • The sensor works best with a hard, flat object placed parallel to the sensor’s front face (note: ultrasound is just high frequency sound – think about how sound can be absorbed by soft surfaces or bounce off hard surfaces).
  •  Us-Dist-Cm mode - the behavior is the same, the display is just calibrated in centimeters instead of inches.

4. Gyro Sensor

  • Gyro-Rate mode - Numeric rotation rate in degrees per second. Measures how fast its rotating.
  • Gyro-Ang mode - Numeric rotation angle in degrees. In angle mode, it only measures the angle of rotation in 1 of 3 dimensions.
  • The Gyro Sensor has a lot of sensitivities and may be very difficult to work with in this mode. See Tips and Tricks. I would be very generous with the answers to this question.
  • The Sensor needs to be reset by removing the plug and re-plugging in otherwise the values may drift when used in this mode. The whole purpose of this question is to get the students to play with the sensor.

5. Motor

  • L-Motor-Rot - in 'rotation' mode, the display shows a value in rotations indicating many times the orange motor hub has been turned. The display starts at “0” and counts both up and down as the motor is turned in opposite directions.  The display will show negative rotations if turned below “0”.
  • L-Motor-Deg - in 'degrees'  mode, the behavior is the same. The display is just calibrated in degrees instead of rotations.  One rotation of the orange hub is equal to 360 degrees.  Rotation mode is most useful for large movements and Degrees mode is better for small movements.