BK stands for BuecherKasten, meaning bookshelf. It controls the physical doors connected to a processing unit (LabJack) by reading user input from a barcode scanner.
It also provides a web interface to manage which user can open which door.
The project is designed for the library of the physics department at ETH Zuerich but it can be expanded when necessary.

The installation steps are described in the script conf.d/InitializeProgram.sh.

• Run the install script as root and answer the questions.
• Now you will need to install the apache2 certificates. See error message: systemctl status apache2.

The librarian has to configure BK over the web. (Assigning the doors to the users) Meaning that if BK gets newly installed because of a hardware defect all of the data from the defect BK is lost.

1. perl BKScanner &
2. perl BK daemon -m production -l ws://0.0.0.0:8008 &

1. systemctl start bkscanner
2. systemctl start bk
3. systemctl start apache2

• Both apps log to the same files log/message_log and log/error_log.
• BK also logs the Mojolicious messages to the log/development.log or log/production.log, depending on the mode.

• BK
• BKScanner
• SQLite Database
• JavaScript Client

This is the Mojolicious all-in-one app, meaning, it is the webserver, door opener and accesses the database.

There are different actions (routes) which BK can process. This information is taken from the URL. The response is in most cases just the content of the book boxes.

It waits for user input from the barcode reader and transmits the username via HTTP request to BK on localhost.

Stores the information which door is assigned to which user.

It has two connection modes: AJAX and WebSockets. The client starts with an AJAX connection and then tries to open a WebSocket. If this succeeds, it continues to use WebSockets as the preferred protocol. If WebSockets are no longer available it will fall back to AJAX.

You can manually force to use AJAX if you set the ws_path to an incorrect URL and then call program_handler.InitializeConnTypeAJAX in the console of your browser. To go back just set the ws_path to the previous correct URL and then wait until it makes a connection (this can take up to 1 min, because of the retry interval).

There are two services, based on systemd service files, the bk.service and bkscanner.service which run the corresponding scripts. They are configured to restart if they crash.

Is the actual webserver which delivers the data but listens only on localhost.

Apache runs a proxy for the Mojolicious webserver and is responsible for the authentication via LDAP. The ws_tunnel module is required to proxy the WebSocket requests.

Hardware Name: LabJack U12
Connection to Computer: USB
Drivers: on LabJack Website
Functionality: power is sent through the digital pins to the magnet on the door for a defined time to open the doors
Programming Method 0: C
Programming Method 1: ProfiLab

Name: Stefan Meyer

There is a BK config file in conf.d/BK.conf which sets some variables for BK. NOTE that the inline c path is still hardcoded, located in lib/BK/Common/CommonVariables.pm. The config file is written in YAML and contains hashes and arrays but should be easy to understand.

• The call of $self->{_db}->disconnect generates an error. Therefore, as a temporary work-around, the DatabaseAccess destructor is commented out.
• WebSockets don't work with Safari, probably because Safari doesn't send the auth header with the wss protocol.

This project is using jBox for its popup in the browser to confirm things.

• https://github.com/StephanWagner/jBox
• http://stephanwagner.me/jBox

There are many error codes which could be thrown by the LabJack:

• http://labjack.com/support/u12/users-guide/4.40

Common Errors:

• Error Code 3 - LabJack n not found.
  In most cases (could also be a software error in which actually the wrong device ID is given, mentioned in lib/BK/Handler/SourceC/DoorsInterface.c variable id_num) it is required to unplug and plug the LabJack back in or a similar method, eg. deactivating and activating the device, this often happens when two instances of BK are running and trying to open doors, therefore, for testing, it is recommeded to comment the SetPins function in lib/BK/Handler/Doors.pm out
• Error Code 40 - Illegal input.
  This is a software error, caused when wrong input it given

Anastassios Martakos

BK - Controls the physical doors connected to a processing unit (LabJack) by reading user input from a barcode scanner and lets you manage these users over a webfrontend.

Copyright 2015 Anastassios Martakos

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.