iPad Pro According to John Gruber Apple Pencil doesn't need any extra hardware/sensor on the iPad Pro display

[friedmud]

**Sorry about the double post, meant to combine this into the post above



The version I've heard is that the tilt detection works by having two emitters in the pencil. One is in the very end of the tip (in the little "ball" at the end of the cone) which is how it can actually detect the position of contact without offset at any angle (this is also why the tip is a bit larger than the SP4 pen, which has the emitter in the pen itself).

The second emitter is farther up I the pen. The digitizer compares the two signals to determine tilt. This is why you can mess up tilt detection by having your finger too close to the tip on screen.

This seems right. I can definitely tell you that Gravity has nothing to do with it... tilt detection works just fine while the iPad is upside down (i.e., face toward the earth) or standing straight up (just tried in bed).