I'm currently using 2 3DM-GX3 sensors where one is mounted to a base platform and is static and the other is mounted to a rotational object. I'm able to obtain the precise bearing of the rotating object in reference to the static platform through some very simple calculations. This is a pretty simple, but very expensive, setup.
I've read through the data sheets pretty thoroughly for the ADXL355/354 and all I see is data feedback with relation to changes in g-force. What sort of data is read from the sensors when they are stationary? What sort of data is read when they are moved in only a single axis? How accurate are the readings on a static sensor?