Doorlock

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Revision as of 14:26, 4 January 2019 by Demotape (talk | contribs) (i²C für Display)
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Doorlock

Release status: stable [box doku]

Description Electronic door lock for the new space
Author(s)  tarwin, tiefpunkt
Download  https://github.com/munichmakerlab/doorlock

Our space has a super smart electronic lock, which we mostly designed ourselves. Woopwoop!

Theory

We needed a lock that allows us to hand out as many "keys" as we like, but without making it super complicated to use. A lot of hackerspaces used SSH keys as "keys" to their space. For us, that's not user friendly enough, as we expect quite a few non-technical folks to have access to the space

After discussions, we settled for a two-factor system, using RFID cards and PINs. Additional means to authenticate may be introduced at another point in time.

Hardware

Frontend

RFID reader, pinpad, and LCD display, connected to an Arduino.

Prototype used an Arduino Uno, which is a little short on pins. A buzzer would be nice, and we currently can't control the backlight of the LCD.

Current version is still based on an Arduino (a smaller one), a LCD display, and the RFID reader, all in a nice 3D printed case.

Locking Mechanism

We got a motor lock on eBay, together with its electronics, and we'll use that. It's a Dorma SVP 2000 series lock.

The electronics have a set of contacts that can be used to get the status of the lock, as well as to lock and unlock it. We currently just use the pins to (un)lock it.

Backend

A Raspberry Pi, which is connected to the frontend over a serial connection (via a USB thingie), and has the motor lock electronics connected via its GPIOs and a relay. No status checks are being done yet.

Schema

                                                           +-----------+
                                                           | RFID      | 
                                                  +-(SPI)--+ Reader    | 
                                                  |        +-----------+ 
 +--------------+              +---------------+  |                
 |              |              |               |  |          +-----------+ 
 | RaspberryPi  +----(UART)----+  Arduino      +--+----------+ Keypad    | 
 |              |              |   (frontend)  |  |          +-----------+ 
 +------+-------+              +---------------+  |                
        |                                         |       +-----------+ 
    (Relay board)                                 +-(I²C)-+ Display   | 
        |                                                 +-----------+ 
  +-----+------+
  | Door lock  |                                                   
  +------------+                                                   

Software

Hosted on Github: https://github.com/munichmakerlab/doorlock, contains both the frontend firmware as well as the software for the backend.

The backend runs on the RPi, and uses a SQLite database to store RFID and PIN information. The "manage_db.py" script can be used to maintain that database.

Pictures

On our tumblr:

HW

  • RFID: Mifare 13.56Mhz RC522 RFID Card Reader Module

ToDo

  • Make the backend more maintainable
  • Allow for better integration with other applications, such as potentially the laser cutter and a cashless payment system.

Resources

FAQ

  • How do I unlock the door? Hold your RFID card on the right side of the box, wait for the prompt, enter the PIN and press the green button.
  • How do I lock the door from outside? press 0 and the unlabeled button next to it on the right, wait for the confirmation message. Check that the door is properly locked!