Some random notes.

Component selection is key to success. Not reading documentation is for quiche eaters.

Did you know you could find and SMD an accelerometer with 500nA (yes, nano-Amperes) consumption and 50 nA power-down mode? Putting things in perspective, on a 1Ah coin cell battery this equates to over 200 continuous measurement years run-time, or if you get creative you could exceed 1000 years...

Put that in your pipe and smoke it.