rgrannell1 / don-t-drop-me

Don't Drop Me!

I've long felt my phone should scream if I drop it, so here's a PWA for that purpose.

Implementation

This is implemented using the devicemotion event. The device is represented as a point (x, y, z) in 3d space:

• x: left to right in the plane of the screen
• y: bottom to top in the plane of the screen
• z: back to front perpendicular to the screen

The acceleration vector will be (0, 0, 0) when the device is at rest. Dropping it will transform this vector with a vector A = (ax, ay, az), with the magnitude ||A|| being ~9.81

To stop the audio triggering sporadically the app checks that a few samples (~150ms worth) indicate freefall simultaneously.