EV3 Calibrate Light Sensor

Calibrating Your Light Sensor

Before moving on to the next task, we need to make sure your light sensor is calibrated.

When we CALIBRATE the sensor, we are adjusting the scale the robot uses to measure the amount of reflected light it is receiving. (Darker surfaces reflect less light than lighter surfaces.)

For example, if the darkest surface the light sensor will aim at and receive reflected light from is black, we will set that to be the MINIMUM amount of reflected light (0%). If the darkest thing the light sensor will aim at is gray or dark blue or some other color, we will set that surface reading to 0%. Then, we will decide what will be the lightest surface that the sensor will aim at and set that to the MAXIMUM (100%)

This is how it will work:

1. Write and use this stack to set the minimum value. For this example, we will choose “black” as the minimum value surface.

2. Set your robot so that the light sensor is about 1 to 2 mm away from the black surface you will be using.

3. Press the “down” button on the brick.

4. The blue light sensor block commands the sensor to read the amount of reflected light from the surface and set it as the minimum (0%)

5. You will hear a beep when the calibration is complete.

6. Write and use this stack to set the maximum value. For this example, we will choose “white” as the minimum value surface.

7. Set your robot so that the light sensor is about 1 to 2 mm away from the white surface you will be using.

8. Press the “up” button on the brick.

9. The blue light sensor block commands the sensor to read the amount of reflected light from the surface and set it as the maximum (100%)

10. Sometimes you may want to RESET the calibration to the original values. To do this, write and use the following stack.