jcparkyn/dpoint

Open-source digital stylus using camera tracking and inertial measurements

dpoint's Issues

UKF Implementation

I want to propose the consideration of implementing the Unscented Kalman Filter (UKF) instead of the current Extended Kalman Filter (EKF) for sensor fusion in the project.

I wonder, if it's possible to encapsulate the actual filter implementation by using abstract or interface-like calls in the update_imu and update_camera functions.

Idea: Body shape to take advantage of sixth D of F

This is an amazingly well-done project which is firmly in the "shut up and take my money" zone! The only thing it really lacks (AFAICT) is a standard software interface (e.g. Wacom) to allow usage in existing applications. With that in mind, here is my idea:

There is a measure of the rotation about the long axis (the nib-to-charging port direction). If the body of the pen was asymmetrical, the user - having an intuitive, tactile awareness of this angle - could better take advantage of it.

A simple flattening of the cylinder is likely sufficient, but perhaps a rounded, slightly isosceles- or scalene-triangular cross-section would be more comfortable. One possible disadvantage of this form would be handedness; although this could be mitigated with clever design and manufacturing techniques.