I published an instructable on Arduino & Android based DIY smart lock which can be open and closed using password sent from Android smartphone over Bluetooth two years back. The instructable become very popular and I got lots of email from the community. Here I am going to publish an updated version of my door lock. Now, the lock is fully 3D printed.
This smart Lock is the secure, simple, and easy to manage your homes lock. This lock needs no keys and the lock is attached inside the door and you can control it from outside the door. As the lock is inside the door there is no way to break the door by a thief. An android application is required to open and close the lock and I will explain the details of android app development in the later part of the tutorial. If the password is matched to your preset-lock password then the lock will be open and sent a feedback to your phone.”