The past month we’ve been hard at work solving the jamming problem described in our previous updates. With this update we have some good news - we believe we’ve solved the worst jams that were preventing lock and unlock operations by hand.
We’ve sent out a couple of beta firmware builds to units that are currently installed, and the results are promising. Lockitron should now still be operable by hand or key in the case where it is unable to lock or unlock your door all the way (or tries to go too far).
We will be working through the weekend to further verify the update as well as collect more data from current users who have the new firmware installed. The great news is that we are resuming shipments, however, to ensure that our new firmware doesn’t hit any snags we are ramping up shipments rather than shipping out our entire stock (2,000+ units) at once. If you’re in the March shipping estimate, keep an eye out for your queued up email.
Deploying New Firmware Updates
An early proof from our sticker supplier shows off a new reminder now included on all packaging. The latest update improves reliability and battery performance in edge cases.
The new update does a number of things differently than earlier versions of Lockitron firmware. Where previously we would drive Lockitron’s motor at full force between various known ‘states’ (Locked, Unlocked, Neutral), we now carefully modulate how much force Lockitron uses to transition from one state to another. This is a delicate balancing act with a number of variables in play. Too little force and Lockitron fails to rotate your lock, too much and it can seize up when jamming against your door frame. To further complicate matters, these parameters need to be adjusted to be compatible across a broad range of lock types and need to be re-adjusted as the batteries slowly drain.
The past month of dedicated study resulted in a new software Lockitron ’ECU’ module, a concept borrowed from the world of automotive engineering. To control Lockitron’s power output we sample various sensors to determine battery chemistry, voltage levels, lock stiffness and recent activity. We map these values to a pre-computed lookup table and optionally perform a few modifications on the result based on lock type. The table itself was generated by sampling a large number of locks on various ranges of sticky doors and using some basic statistical methods to calculate a happy operational median. From this table, Lockitron determines how fast it should turn your knob in order to complete a Locking/Unlocking operation successfully without irrecoverably jamming itself.
The result of all this work is a ‘smart lock’ considerably more sophisticated than earlier mechanical pin and tumbler designs. Where traditional locks rely on the mathematical equivalent of matching a five-digit pin in the form of a key with another five digit pin in the form of a series of tumblers, your Lockitron comes with a cryptographic co-processor, an analog differential equation solver, and a dynamic statistical modeling tool!
Some locks rotate clockwise to lock while others rotate counter-clockwise. Similarly, jams that occur when locking are treated differently than those found when unlocking. Factors like these (along with battery chemistry, voltage levels, lock stiffness and even when Lockitron was last used) combine to yield surprising complexity in recovery logic.
Battery Life and Notifications (part 2)
In our last update we mentioned some of the additional notifications we were working on. One of the most critical of these is our low battery notification.
We’ve just released the first version of this warning message and will be fine tuning it over the next week to work with different battery chemistries. The low battery notification should give you enough time to change your batteries before Lockitron stops and is unable to turn your lock.
In addition, we’ve been working hard on bringing much more information and control to your Lockitron from our API and mobile apps, including:
- Information on when Lockitron is updating (and the ability to restart the update if it fails during this step)
- Exact information on how long Lockitron is “sleeping” for when you send a remote command over WiFi
- The ability to cancel all pending lock and unlock commands which may have sent by accident
- WiFi network strength and connection quality
Make sure to sign up for our developer mailing list where we will keep you posted as new features become available.
Help Us With a Quick Installation Survey
We could use your help with a quick survey about your installation plans for Lockitron. We promise it won’t take more than a minute or two - take a look athttp://lockitron.polldaddy.com/s/installing-lockitron.
In addition, make sure to take a look at the Lockitron installation and troubleshooting videos before setting up your unit.