I currently use CM11 nightly from 27-06-2014 and my device stopped auto rotating. I disabled it and enabled again, did not help. Reboot did not help. Shutdown and boot did not help.
For now I need to use an app to rotate the screen manually.....
How do I get auto rotate back? How can I calibrate the sensor?
What about /system/etc/sensors_calib.conf ? Can you there force Android to calibrate sensors?
SOLVED: I completely wiped the phone and restored the nandroid backup. Sensors work again now.