entry.page

---
title: Space Entry Project
categories: projects
...

# Current Implementation

A box (the Automatic Deadbolt Mechanism or "ADM") is attached to the existing deadbolt;
the ADM can lock or unlock the deadbolt.

Pressing a button on the ADM will lock the deadbolt after 5 seconds.

An opto-isolated input to the ADM will unlock the deadbolt. The input is a single bit; drive it high for 1 second to unlock the deadbolt. Driving it high for more than 1 second is not recommended (it will make the ADM unlock the deadbolt again and again).

Another opto-isolated one-bit input will lock the deadbolt immediately; drive it high for 1 second to lock the deadbolt.

The ADM supplies two opto-isolated output bits that report the position of the deadbolt, based on two limit switches ("locked" and "unlocked"). A high signal means the deadbolt is at a physical limit; a low signal means the deadbolt is not at a physical limit. The deadbolt might be between the two limits: both bits will be low. If both bits are high, something is broken, since the deadbolt cannot be at both the locked and unlocked positions at the same time.

A door switch supplies another output bit that tells whether the door is open or closed; a low signal means the door is closed.

There is an Access Control Computer ("ACC" -- a BeagleBone Black) connected to the deadbolt control and status bits and the door switch bit. It is running Arch Linux ARM and communicates with the ADM via the /sys interface to the GPIO. A simple high-level interface is provided via [doord](https://github.com/DavisMakerspace/doord).

## BeagleBone Black Info

Only some of the GPIO on the BBB seem available to the Linux kernel.  Through experimentation, the following seem usable:

      P8: 7-19,26
      P9: 11-16,21-24,26,27,30,41,42

The board documentation describes how the pins correspond to GPIO numbers.

## UPS

A UPS powers the ADM, the ACC, a USB hub attached to the ACC, the DSL modem, and the router. The system can keep running if AC power has failed; it could send a message to notify us of a power failure.

A USB cable connects the UPS to the ACC so that the ACC knows if the power has failed.

## Open Issues

### (none)

# Brainstorming

Feel free to brainstorm ideas here.  Unless otherwise specified, lists here are meant to be exhaustive, and not necessarily design goals..!

## Authentication Methods

- RFID
    - Good for longer-term authorizations, e.g. members in good standing.
    - Unlike QR, no visibility of key required, just proximity.
- [QR Code Entry]()
    - Good for temporary authorizations.
    - Easy to cancel and regenerate in case of loss.
    - Less convenient since requires visibility.
    - Cheaper per key vs RFID.
    - Could be implemented with a Raspberry PI and a webcam [example project](http://www.raspberrypi.org/archives/2504)
- Facial recognition
- Thumbprint
- Electronic manual override
- Physical manual override
- Login and unlock via local WiFi
- Knock code
    - e.g. have to tap a certain rhythm to unlock.  Though any means of 'tapping' could be possible, e.g. flashing a light, making sounds, etc.
    - probably best for limited time or one-time authentications.
- [USB key entry]()
    - could be dual-use with dead-drop port
- Bluetooth pairing

## Authorization Types
 
- Persistent authorization for e.g. members in good standing
- One-day/one-time authorization for e.g. guests
- Dependent on certain conditions, e.g.
    - only in given time frame
    - someone already in the space

## Management

- Authorize an authentication via multiple interfaces
    - IRC
    - Website
    - Kiosk in space

## Monitoring

- Announce entry/exit on IRC
- Could run a user created script at door open, like on login

## Possible data to store:

- Code
- Date/Time created, used, expires
- Created by/for
- Status (active, expired, revoked)

## Relevant external projects

- [Lockitron](https://lockitron.com/)
- [Instructables](http://www.instructables.com/id/Arduino-RFID-Door-Lock/) - RFID project
- Eugene Makerspace has some interesting [ideas](http://www.eugenemakerspace.com/wiki/Sites/ElectronicDoorLock)