Calibrating the Harmony N380 System:


1. Turn system power on


2. Pedal the bicycle lightly through the entire calibration procedure 


3. Press and hold the "mode" button (the silver/chrome button on the shifter) until the rear hub begins shifting (5-7 seconds typically), then release the button.


4. Continue pedalling lightly while the system shifts from "low" to "high" ratio multiple times and completes the calibration.


Here is a link to the complete manual for your reference:


Harmony Manual