I've got an app in mind, using an Arduino MCU (my tool of choice, I realise ymmv), where it would be very handy to have wireless IMU in multiple places. With moving parts -- especially human parts -- trailing wire harnesses and repeated flexing are really a PITA. So hmmm, I've been surveying the marketplace. So far it's pretty frustrating.

mbientlabs makes what looks like the ideal gizmo (a little spendy, but perfect features and packaging). however, I cannot find any low-level info about how the thing actually communicates. mbient has buried it under mountains of OO SDK to help me develop for Windows, iOS, Android etc. Not interested. Just want to exchange some bytes (or at most a JSON dialogue over HTTP) with the BLE device.

I found some dandy coin-powered IMU with no BLE, only i2c. I found some big clunky RF solutions -- but no one wants a mint tin strapped to their ankle or wrist. anyway, in the course of this treasure hunt I found this group... and thought y'all would be the perfect people to ask.

does anyone have a line on a subminiature, wearable, coin cell powered, 6-axis accelerometer/gyro with BLE (or other low-power radio) whose communication protocol is simple enough that I could interrogate it from a BLE (or other low power radio) equipped Arduino? If there was already an Arduino library for it, that would be just icing on the cake! if it had smart enough power management to make the coin cell last longer than 24 hours of continuous use, that would be gilding on the icing.