X and Y and Rotation

The first tilt experiment measured how far the micro:bit tilted away from being held level.  The test isolated each axis.  So, when you tilted it toward and away from you, there was minimal left/right tilt.  So, the y-axis measurements changed while the x-axis measurements only varied slightly.  Then, when you tilted it left and right without tipping the micro:bit toward or away from you, the x-axis changed, and the y-axis only varied slightly.  

You can also set the micro:bit on its edge, like it’s a wheel.  As you rotate it, both the x and y axis measurements will go through their ranges.  

If you instead tilt it toward a corner, the x and y axes will return measurements, each indicating the portion of gravity it senses.  For example, you might see a measurement like (512, 512).  If you balance it on a corner, you might see a measurement like (736, 736).   Note that the measurements are different, but their ratios are the same.  More about that in the next activity.

Try This: Take X and Y Rotation Samples

Let’s treat your micro:bit like it’s mounted on a wheel, and watch the x and y values change. In the next activity, you will use a script to calculate the rotation angles.

• Use the same script: test_tilts_intro.
• Flash the script into the micro:bit and open the terminal.
• Test at each rotation shown in the animation.

• Fill your measured values into the table.