Project Description

This project uses the ARM mbed to model a simple in-home security system. The alarm is turned on using bluetooth, and is activated by either motion or noise. When activated, the alarm system alerts the home owner by sending a message via bluetooth to the home owner's mobile device. This message states that the alarm has been toggled on, and whether motion or noise was the trigger. The system also sends a follow-up message once the alarm is toggled off.

Parts Needed

• ARM mbed
• Sharp IR Distance Sensor
• MEMS Microphone
• Adafruit Bluefruit BLE UART Friend Module
• RGB LED
• Three 100-330 ohm Resistors

Hookup Guide

Sharp IR Distance Sensor

MEMS Microphone

The microphone does not always work as expected and may not detect noises.

Adafruit Bluefruit BLE UART Friend Module

This Adafruit Bluefruit Module can be controlled through a free mobile application for iOS or Android devices. The switch on the top of bluefruit module must be set to "UART" to properly function.

RGB LED

Voltage dropping resistors must be used with the RGB LED or it will burn out. Resistors from 100-330 ohms are typical values used.

Wiring On a Breadboard

Video Demonstration

This is a demonstration of how the system works. Using the Bluefruit LE application on a mobile device, the system is turned on using the control pad. Then, switch to the UART screen on the application where you can check if the alarm has been set off or not. In the video, motion detection and sound detection functionality are displayed. When the sound is detected, the LED turns green and the UART prints out that the alarm has been toggled because of a sound. When motion is detected, the LED turns red and the UART prints out that it detected motion.

Code