DEC0905
The objective of this project is to enable users to remotely control home appliances and systems over the
Internet using a web interface. The system will enable users access a web interface running on a server located at home. Users will be able to monitor the status of the home appliances, and issue control commands to perform specific functions. For Example open or close a garage door, program the home security system, reprogram the lawn watering system, etc. A function completion code is then returned to the user. The interface to home appliances will be through wireless Bluetooth communication. A microcontroller will be connected directly to the appliance being controlled and execute the commands. It will also interpret the feedback information and send it to the server.
Design and Implement a system that will enable users to remotely control their home appliances through the Internet and get feedback from the appliance.
The system designed will provide a new product to the newly emerging automation and controls market. It will be used in households to remotely control and monitor various home appliances through the Internet.
User
• Must Be Wireless
• Must use a wireless technology
• Must be able to control the device
• Must be able to parse and interpret commands
• Must be able to send and receive messages from the access point
• Must communicate with the server wirelessly
• Must interface directly to the Microcontroller
• Must be accessible from the Internet
• Must send commands through the access point to the microcontroller
• Must be able to receive commands from the access point.
• Must be able to send status messages to the server wirelessly through the access point.
• Must be able to receive user input
• Must display the devices, and controls to those devices, to the user
• Must have a logon method for verifying users
•Access point must have a footprint of less than 50 feet
• Wireless antennas must be internal or shorter than 4 inches
• GUI must have an intuitive look and feel for the user
This system consists of several units that would operate both indoors and outdoors. Most of the system components will operate indoors under normal room temperature. The device control unit would operate both indoors and outdoors depending on the location of the device. The system would operate within the temperature and humidity limits for proper operation of hardware. A secure Internet connection would be necessary for the operation of the system .
Internet
IR Sensor
Server
Bluetooth
USB
Adapter
Bluetooth module
Microcontroller
Garage door
Opener
The server contains several parts. The first of which is an HTTP servlet that runs server side. When this servlet is loaded it sends out a broadcast for all available Bluetooth devices. The devices are filtered for the Easy Bluetooth module, and the servlet gives the command that it is ready.
The second part of the server is the user interface. Once the servlet is ready, the user may go to the website which is running the servlet. The servlet passes back a list of devices found, and the user may select from a list of devices and start sending messages to the device. JavaScript is used to call an
AJAX request to the servlet in order to pass off communications
The Bluetooth USB adapter connected on the server side should be able to communicate to the microcontroller by sending and receiving data to the Bluetooth module that is connected on the UART
(Universal Asynchronous Receiver / Transmitter) on the micro-controller board. For the purpose of
Bluetooth communication, a specific protocol has been implemented to ensure the quality of data delivery and to provide a defined programming interface.
Bluetooth Adapter
Bluetooth Module
Bluetooth Connection n
Device name (**)
Request for command
Send device name {gd,th} for garage door and thermostat respectively a
Request a universal action b
Acknowledgement
* b
Request action * = {u,d} for opening or closing the garage door respectively
Acknowledgement (command executed)
Bluetooth Module s Request the current status of the garage door.
Status is detected by the IR sensor.
Relay circuit
* * Respond the with status ** = {up,dn,op,cl} where
• up: garage door currently opening
• op: garage door already open
• dn: garage door currently closing
• cl: garage door already closed
Device control unit is the major component of this system. It consists of a microcontroller and a Bluetooth module. This unit will connect directly to the device and control the functioning of the device based on the commands received from the server. DCU connects to the server through Bluetooth using the Bluetooth module. DCU will communicate with the server in order to receive commands and send responses in order to provide status data to the user.
An IR sensor is used to detect if the garage door is open or closed since the user might simply request the current status of the garage door.
This refers to the home appliance that is controlled by the DCU. Appliances considered for this project is a garage door opener. A relay circuit is used to connect the microcontroller to the garage door opener.
The functionality of the server was first developed using a test program. This program allowed us to connect to the microcontroller via Bluetooth connection without using a fully developed web server.
In later development of the server we also used a dialog box to let us know what actions were being performed on the server.
Since the microcontroller communicates to three separate devices via UART, a test module that communicated through a computer’s serial port was developed using the UART library and a serial communication program called Bray’s Terminal.
Once the UART code was developed for basic serial communication, three separate test modules were developed for the infrared sensor, Bluetooth device, and garage door relay. Each module was developed to run on a separate port of the microcontroller.
An LCD screen connected to the microcontroller was used to output results for each test module until the
Bluetooth server was fully functional.
Test Program
HTML GUI
Server Dialog
Bray’s Terminal
LCD Module
Easy Bluetooth Module $70
LMX9820 $27
Bluetooth USB Adapter $15
IR Sensor $10
Garage Door Opener Donated by Door & Fence Store
Microcontroller Donated by Team May0613
Poster
Total
$50
$ 172