---
title: "Gatekeeper"
url: "https://maker.wiznet.io/minsu/projects/Gatekeeper/"
markdown_url: "https://maker.wiznet.io/minsu/projects/Gatekeeper/md"
type: "UCC: User Created Content"
author: "minsu"
author_url: "https://maker.wiznet.io/minsu/"
original_author: "minsu"
original_url: "https://wiki.nottinghack.org.uk/wiki/Gatekeeper"
published: "2019-04-02"
language: "en"
hardware: ["WIZnet W5100 ethernet shield"]
likes: 0
views: 474
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# Gatekeeper

> Gatekeeper

Original author: minsu (source: https://wiki.nottinghack.org.uk/wiki/Gatekeeper)

## Components

- **WIZnet W5100 ethernet shield** x 1 ([docs](https://www.wiznet.hk/en/open-source-hardware/102-w5100s-ethernetshield.html?search_query=W5100+ethernet+shield&results=84))

## Documents and links

- [daniel1111](https://github.com/NottingHack/instrumentation) (code)
- [Gatekeeper Shield](https://wiki.nottinghack.org.uk/wiki/File:Gatekeeper_Shield.png) (schematics)

## Article

Gatekeeper is the first node of our Hackspace Instrumentation project to go live and is responsible for access control to the space through the front "Airlock" door. ![](https://maker.wiznet.io/uploads/2019/04/keeper3-238x300.png)

### Source Code

The firmware that runs on the arduino cane be found here <https://github.com/NottingHack/Gatekeeper> The code for the database and the process that run on [Holly](https://wiki.nottinghack.org.uk/wiki/Holly) can be found here <https://github.com/NottingHack/instrumentation>, the relevant part is [GateKeeper.cpp](https://github.com/NottingHack/instrumentation/blob/master/cpp/GateKeeper.cpp)

### Logic Flow

![](https://wiki.nottinghack.org.uk/images/1/1a/Gatekeeper_Logic_Flow.jpg)

### Quick Breakdown

- Arduino with Wiznet shield

- RFID reader

- Doorbell button (interrupt pin)

- magnetic release (MOSFET switch 12v)

- Magnetic contact

- Doorbell sounder (Relay) - activated either by attached doorbell button, or doorbell on outer door (connected to main [LED Matrix](https://wiki.nottinghack.org.uk/wiki/LED_Matrix) display)

- Magnetic release status led's red/blue (TODO)

- Matrix keypad and HD44780 LCD controlled via I2C AtTiny2313

- MQTT

- MQTT scripts on holly push door opened & last man switch events to irc twitter and log

- Card numbers in 'Instrumentation' MySQL database on [Holly](https://wiki.nottinghack.org.uk/wiki/Holly)

- Database managed by [HMS](https://wiki.nottinghack.org.uk/wiki/HMS)

---

Source: https://maker.wiznet.io/minsu/projects/Gatekeeper/