Do I have to turn on / off the device? You do not need to. The meter automatically goes into the active and sleep state when driving starts and stops Tagged: power meterpowercranktwin2 Related Articles How to install and start the device? Where can I find serial number and ANT+ ID? How to connect the POWERCRANK with my bike computer? How to perform calibration? What do the calibration values mean? How often do I need to perform calibration on my device?