Implementation of a Distributed Home Automation Scheme with Custom Hardware Nodes Using ZigBee and MQTT Protocols.

Providing safety, security, operational convenience and energy savings are some of the vital goals of a home automation system. A single unified point of interaction for the user is also an important consideration. Each feature requires a different sensor, powering scheme and mounting arrangement. To address each requirement, custom node development is to be prepared with all nodes being part of a personal area network for data transfer. A central node with Internet connectivity can push data to the cloud and the user can be provided access to data on a mobile app. This paper presents the practical implementation of such a distributed home automation scheme with custom-designed microcontroller-based ZigBee enabled hardware nodes for liquid petroleum gas leak detection, window open detection, lights switching control based on occupancy and intrusion detection. Messages are triggered by events and are not periodic to avoid traffic congestion. A central node built around a Raspberry Pi with a ZigBee dongle will serve as a data aggregator which sends messages to our own MQTT (Message Queuing Telemetry Transport) broker. An android mobile app will work as an MQTT client, helps the user to connect the MQTT broker, subscribe to the topics published and makes alerts to the user as soon as an event occurs. The mobile app will also enable the user to switch on lights and other appliances through command messages sent to the MQTT broker and subscribed to Raspberry Pi. [ABSTRACT FROM AUTHOR]