Data streams from the Arduino containing live position data (6 axis: 3 angular orientations from gyroscope, and 3 accelerations which can be integrated to determine positions - note this does have an associated drift error that increases with time and need recalibration according to the Designing VR Systems books chapter 8?)
This paper has a lot of the maths I think willl be useful to create a rotational inertia generator:
Design_Analysis_and_Preliminary_Validation_of_a_3-DOF_Rotational_Inertia_Generator_.pdf
Accelerometer data can be converted into position based data using Runge-Kutta Integration or Euler Integration (Runge Kutta is computaionally a bit more expensive, but numerically more accurate (see section 8.3 of LaVille)
Need a way for events detected in Unity to trigger the right responses to be sent out to the Arduino.
To create a secondary vibrational feedback - novel idea, have not seen it in literature!
demo:
https://www.desmos.com/calculator/1zsnxcr46n
look at the references of the 3DoF paper above for inspiration (here: Design, Analysis and Preliminary Validation of a 3-DOF Rotational Inertia Generator * | IEEE Conference Publication | IEEE Xplore)
of a Haptic Compass Based on Asymmetric Torque Stimuli
Paper here (IEEE Xplore Full-Text PDF:)