The Levelogger App Interface has an LED light that indicates its status when it is turned on.
Green light flashing every second: Ready/waiting for a Bluetooth connection to be made from your smart device.
Blue light flashing every 3 seconds: Bluetooth connection has been made.
On an Android device, the light will not flash blue until the Bluetooth connection is made and the Solinst Levelogger App is open.
Yellow light: Levelogger App Interface is turning off while the power button is held pressed.
Red light flashing every 10 seconds: Batteries are low. Replace the batteries.