This document describes a home automation system using Raspberry Pi, MQTT messaging, Grails, and Arduino. The main components are an MQTT broker to organize messages, a Grails/Tomcat web server for centralized logic, a Raspberry Pi, browser interface, and Arduino board. The system allows remote control and monitoring of sensors and devices in real-time through a browser dashboard using MQTT, websockets, and Ajax. An Arduino board interacts with sensors and devices using a relay board and publishes data to MQTT channels.

1. HOME AUTOMATION
Raspberry Pi + MQTT + Grails + Arduino

2. WHO AM I?
Cássio Landim
Freelancer Software
Developer
twitter.com/cassiolandim
facebook.com/cassiolandim
br.linkedin.com/in/cassiolandim
github.com/ziglee

3. COMPONENTS
• MQTT Broker (Mosquitto)
• Web Server (Tomcat + Grails)
• Database (H2 File)
• Raspberry Pi 2 Model B
• Browser (WebSocket + Ajax)
• Arduino (Relay Board + Sensors + Buttons)

4. Components interaction

5. RASPBERRY PI 2 MODEL B
900MHz quad-core ARM Cortex-A7 CPU 1GB RAM

6. MQTT BROKER
• MQTT provides a lightweight method of carrying out
messaging using a publish/subscribe model
• Mosquitto (Open Source MQTT v3.1/v3.1.1)
• Central component
• Organizes all messages/events in one place
• Has many clients implementations (Languages & Platforms)

7. WEB SERVER
• Centralizes the logic (e.g sends an email when doorbell button fires)
• Tomcat 7 (JDK 7 + Servlet 3.0)
• Grails 2.5.0 (Groovy language)
• Web-socket plugin (Spring)
• Paho MQTTv3 Java Client Library (Eclipse)
• Subscribed to channels sensors/status and switches/status and publish this
data to WebSocket topics
• Publishes to channels like lights/kitchen/set with message “on” or “off”

8. BROWSER
Remote interaction with realtime feedback

9. BROWSER
• HTML
• Javascript
• Ajax (Post events like “turn on room lights”)
• WebSocket (refreshes dashboard with real time data)
• Bootstrap (http://getbootstrap.com/)
• JustGauge (https://github.com/toorshia/justgage)

10. ARDUINO
Open-source electronics platform

11. ARDUINO MEGA
• Interacts with real world through 54 digital input/output pins
+ 16 analog inputs and with MQTT Broker via Ethernet Shield
• Periodically publishes a JSON with all sensors data on channel
sensors/status
• Publishes a JSON with the status of all the switches on
channel switches/status when an event occurs
• Subscribed to channels like buttons/room and lights/room/set

12. RELAY BOARD
http://www.labdegaragem.org/loja/relayboard.html

13. RELAY BOARD
• Expansible
• 3 control pins
• 8 relays
• 12Volts

14. OPEN SOURCE CODE
• https://github.com/ziglee/home-automation-web
(Grails)
• https://github.com/ziglee/
HomeAutomationArduinoCentral (Arduino)