(last updated: 2006/11/03)
Purpose: A wireless garage door sensor that detects open/closed state and raises an alarm if the door is open during a specified time. Entry for Circuit Cellar "Atmel AVR Design Contest 2006" - received "Distinctive Excellence" award.
Overview
This project allows you to remotely monitor the open/closed state of a door. It was designed for a garage door; however, there is nothing about the design that prevents it from being used to monitor anything where an object moves away-from and close-to the sensor. Even though this design shows only one sensor, it can be expanded to be a multi-sensor system.
The Maxstream XBee (802.5.14/Zigbee transceiver) is used to wirelessly send data that is collected by an inexpensive, low pin-count, microcontroller. The data is received by another XBee that is interfaced to a PC through an FTDI USB-to-RS232 module. A PC program runs in the system tray and changes its icon depending on the sensor's state. If the door is open during a specified time period, an audible sound is played and the icon flashes.
See the documentation for the full specifications and design details.
Block Diagram
Download (see Attachments)
SimpleWirelessSecuritySystem - all project files including documentation, source code for the Atmel ATtiny45 (AVR Studio using WinAVR), and source code for Visual C# (used Express Edition)
Notes:
1. This project was submitted for Circuit Cellar magazine’s "Atmel AVR Design Contest 2006". Received "Distinctive Excellence" award.
Copyright Steven R. Nickels, 2008. All rights reserved.