How does ZeCircle calculate my sleep quality? August 07, 2015 12:18 Updated Our 3 axis accelerometer sensor determines whether your are in a phase of light sleep, deep sleep, or awaken. Related articles It seems the number of steps I have done is inaccurate. MyKronoz Academy - ZeCircle Tutorial How can I read and reply to SMS messages received ? How do I activate sleep mode? I receive the error message "server busy", what can I do ?