Motion detection utilizes the accelerometer’s data to detect, whether the Tag is moving or not. This information gives the tag possibility to go into sleep mode once the Tag is stationary.
This brings two benefits: it prolongs the battery lifetime and decreases communication workload over the channel.
Tag provides four sleep mode options:
• Disabled - Tag send blink message regularly and movement detection is inactive.
• Delayed sleep - Once no movement is detected, tag remains sending blinks for a 5 second period and then go into sleep mode. This mode can be useful in scenarios when accurate position is required at the spot where tag was stopped.
• Immediate sleep - Tag is put into deep sleep immediately after no motion event is detected.
• Keep alive - Tag is put into sleep immediately after no motion event is triggered, still it sends blink every 5 seconds. After the blink is sent, the tag is put back into deep sleep. This feature is useful for static tag tracking. This mode is available from FW 3.118.
Movement event threshold could be set via tag configuration (wireless or NFC - Tag Leonardo only). Implicitly it is set to most sensitive value. Different types of Tags have different accelerometers therefore it is recommended to test threshold level for given tag type and particular application.