Encountered some issues - please add to documentation
For PMW3389 Motion Sensor
Let me list the issues I had getting this module operational:
Source code: The source code only reads the low-byte of DELTA_X and DELTA_Y, which was confusing to me in the beginning. It should be demonstrated in the code that this delta values are not 8-Bit values, but instead 16-Bit values, and possibly explain to beginners the Two's complement representation. My simple application now samples every 100ms and reads both high- and low- bytes of DELTA_X and DELTA_Y and everything really runs smoothly. For every inch I move the sensor, the values change by the offset of 16000, what is the indended behaviour.
Distance of lense to surface: It should be mentioned that the lense must have a distance of 2.1mm to the surface in order for the module to work. I got this information from the data sheet of the PMW3389. It should be mentioned in the documentation that the user has to use this module inside some own baseplate, which creates this distance to the surface.
Hardware: It is nice that you provide this breakboard module, but it would be even nicer if you could provide it together with some kind of versatile baseplate that creates this 2.1mm distance to the surface and can be used for prototyping. Not everyone has a 3D printer at home and can create such a baseplate.
Shipping to germany had no issues, great product, although there could be more source code examples what can be done with it. The original manufacturer does not disclose too much information to non-commercial companies or users.
