by Varun
We had a great learning experience today. One of our missions was using light sensors for detecting lines on the mat. We noticed that the mission started failing when we had one of the lights in the room off. We started researching this further and learned about calibrating the light sensors.
Calibrating light sensors helped our team a lot to make the EV3 perpendicular with the black lines on the mat. We made a calibration program for the light sensors, because we thought the lights at the tournament stadium would shine differently than at our place where we practice at. The program just asks what is zero (darkest area on the mat) on the mat and what is hundred (lightest area on the mat) on the mat. What the program first does is, resets the light sensor, so it will come back to zero. Next, the words Measure Dark will show up on the EV3 brick. You have to place the light sensor on the darkest area of the mat so it can find out what is zero on the mat. After that, it will wait until the center button of the brick will be bumped so it will know if you are ready or not. Then, it will calibrate the minimum value of the darkest area. The words, Measure Light will then show up on the brick. You have to place the light sensor(s) on the lightest area on the mat so then the EV3 can then know what 100 on the mat is. The EV3 will wait until you have pressed the center button of the EV3 brick to know that you are ready. Finally, the EV3 will calibrate the minimum value of the lightest area on the mat.
Once the sensors are calibrated, the brightest area on the mat is guaranteed to read as hundred, and the darkest area as zero. All other shades are calibrated in between.
Calibrating light sensors helped our team a lot to make the EV3 perpendicular with the black lines on the mat. We made a calibration program for the light sensors, because we thought the lights at the tournament stadium would shine differently than at our place where we practice at. The program just asks what is zero (darkest area on the mat) on the mat and what is hundred (lightest area on the mat) on the mat. What the program first does is, resets the light sensor, so it will come back to zero. Next, the words Measure Dark will show up on the EV3 brick. You have to place the light sensor on the darkest area of the mat so it can find out what is zero on the mat. After that, it will wait until the center button of the brick will be bumped so it will know if you are ready or not. Then, it will calibrate the minimum value of the darkest area. The words, Measure Light will then show up on the brick. You have to place the light sensor(s) on the lightest area on the mat so then the EV3 can then know what 100 on the mat is. The EV3 will wait until you have pressed the center button of the EV3 brick to know that you are ready. Finally, the EV3 will calibrate the minimum value of the lightest area on the mat.
Once the sensors are calibrated, the brightest area on the mat is guaranteed to read as hundred, and the darkest area as zero. All other shades are calibrated in between.