Add an additional Use Case with Sensor or Firmware

Product name

Smart Lock 2.0


On your homepage (installation check), there are only two use cases when opening with the key from the outside:

  1. The inner key turns in sync while un-/locking from the outside
  2. The lock cannot be un-/locked when there is a key on the inside

One use case is missing though, due to another type of lock available on the market:

  1. There also exist lock cylinders where a key can be plugged in on the inside and still allows the un-/locking from the outside BUT where the inner key does not turn in sync with the outer one.

This case confuses the smart lock (or makes it unusable until changing its state manually with the ring), because while the lock has actually changed its state with a key (e.g. from locked to open), the smart lock doesn’t know anything about it (the mechanism of the smart lock hasn’t be used to open or lock)


While this use case seems almost impossible to solve mechanically, I think the door sensor could be used pretty well to overcome this problem - at least in one way:

Say a user leaves his house and locks with lock’n go. When returning home, uses his key instead to open the door. The sensor would now recognize that the door has opened and could trigger the smart lock to change its state to unlocked (i.e. logically an open door cannot be in a locked state).

The tricky case, is when a user leaves the house and locks with the key. There is no way he can then trigger the smart lock via Software to open the door.

Maybe Easiest Solution

I don’t know how the electrical motor in the smart lock works, but I would assume that the range of movement - which is set during calibration - is then set by / in the firm- / software on the smart lock itself. If say the firmware would be programmed to allow the motor to unlock when the lock is already unlocked, or lock when the lock is already locked, basically by disregarding the state saved in the software and just execute the motion (until resistance may be encountered)… that would avoid any confused or polarised state of the smart lock…

I must point out that we prominently ask/show this is one of the first questions of our installation-guide “Is my door lock compatible with Nuki Smart Lock”:

We already got the problem here that we still don’t know the position of the key. So evening knowing it is “unlocked” still leaves the Smart Lock not correctly calibrated which means it can e.g. not pull a latch correctly which can lead to incorrect functionality.

Always forcing the motor to go on as long as possible will lead to not only problems with a latch, but also to block more often and drain the batteries fast. Same problems apply if you recalibrate the Smart Lock every time the door is opened while status was at “unlocked” with the additional risk of interfeering with manual lock actions.