Device Orientation

[J Decker]

How do I enable device orientation?  Is it associated with VR?

My program is not causing the browser to ask for permission...

I get orientation events from 

emscripten_set_deviceorientation_callback( myState, true, em_deviceorientation_callback_handler );

With the sensors panel in devtools, I can force device orientation (which has alpha,beta,gamma...) but I get an event with NaN,NaN,NaN.