First of all, I want to thank Shelly for the creation of this page. For those of us concern about privacy, using Facebook as a communication media for solving technical problems was a great error.
I have several shellys 2.5 used for controlling roller shutters and, despite of having followed the suggestions indicated in the "CALIBRATION TIPS ROLLER SHUTTER" document , the calibration method does not accurately fit to my roller shutters.
The shellys perfectly detect the top and bottom positions. The problem is that if I send a command to set the 50% position, the real position where Shelly moves the shutter is not 50% but 65%, i.e. lower than real 50%. It should be necessary to allow a 50% setting as other devices have.
Why is that so? I suppose that is because the roller shutters that are common in Spain continue descending once they get to the bottom position because the different parts (slats) that compose a shutter insert one inside the others.
You can see this in the attached video from the 1:07 s to the 1:12 s.