The security system will be divided into five main parts: the Arduino sensor nodes, the RF network that connects each node to the Raspberry Pi, the MQTT broker that connects the RF network to the web application, the web application that manages the senor events and alerts, and the database that stores the configuration of the sensors and alarms and the history of each sensor.

Each sensor node is comprised of an RF module that allows communication between the network of sensor nodes and several security sensors, such as PIR motion detectors and reed switch doors or window sensors, and both the standard sensors used on the standard home security systems. While these nodes can be battery powered for better reliability, we will power ours by using a USB port and USB power supply.

The Raspberry Pi will serve as both the host server for the web application and database and the base node in the RF network. This will use the same RF modules and software libraries as...