Introduction: Smarkey


This instructable belongs to a huge project. This is just one part of it. In case you found this page first, please visit the main project

Our door opener works smartly to make life easier and more comfortable. It’s a mechanism inserted in the doorlock which opens the door if you are close to your home and closes the door if you are inside or if you left. How does this mechanism know if you are nearby? It uses bluetooth to keep in contact with your smartphone and it can be managed through the app Frontend.

This is part of the final project named “Home automation” of the course “Multimodal Media Madness” which belongs to the Media Computing Group at the RWTH Aachen University. More information about this and previous projects can be “browsed” on the website The creation of innovating tools which make life easier and personal fabrication are the main topics of the project, which was possible with the by means of a 3D printer, 3D-design software and an Intel Galileo board.

Step 1: Hardware

  • Motor, gear and supplies
  • Milling cutter
  • Bluetooth USB stick
  • Galileo Gen 2 (+ Ethernet and Micro USB cable)
  • Key holder (3D-printed)
  • Holding for the door
  • Door, lock and key
  • Hall Sensor and two magnets
  • Additional power source for the motor

Step 2: Software

  • Arduino Sketch & Galileo Image
  • Print file for the board
  • OpenSCad: Key holder 3D-model and Case 3D-model

Step 3: Other Requirements

Circuit diagram of the board.

See the attached PDF for the circuit of the diagram.

The *.brd file for the PCB Mill is also attached.

Step 4: Mode of Operation

We used another instructable-project ( to know how we could increase the torque of our motor. The shaft of the motor has to be placed on the key and introduced in a 3D-printed key holder (see 3D-model).

To make possible that the door stops when it finishes the process of closing and opening, we sticked a hall effect sensor on the motor (see gif). With the aid of two magnets it can be detected whenever half a rotation takes place.

In order to have the motor properly fixed and steady we constructed a holder which must be screwed on the door.

The circuit which connects the sensor and the motor was built on a breadboard. This breadboard is at the same time connected to the Intel Galileo Board (see photos). What’s more motor and transmission need an extern power source.

The door get opened and closed with the aid of a button or bluetooth. The whole mechanism can as well be managed using the webinterface or the app (see video).

Step 5: Final