Remote Control of Home Appliances Using the Internet

Team DEC0905•Elie Abichar •Rachel Ayoroa•Chris Tefer •Ananta Upadhyaya

Faculty Advisor & Client:•Dr. Ahmed Kamal

Website: http://seniord.ece.iastate.edu/dec0905/

DEC 0905 2

AbstractProblem Statement Design and Implement a system that will

enable users to remotely control their home appliances through the Internet and get feedback from the appliance.

Need Statement 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.

DEC 0905 3

Concept SketchUser

Server Bluetooth USB

Adapter

Garage door Opener

Bluetooth module Microcontroller

Internet

IR Sensor

DEC 0905 4

System Operating Environment

• The system components will operate indoors under normal room temperature or in an environment protected from weather elements.

• The system would operate within the temperature and humidity limits for proper operation of hardware.

• A Internet connection would be necessary for the operation of the system.

DEC 0905 5

Functional RequirementsBluetooth Dongle

• Must Be Wireless• Must be able to send and receive messages from the

blue tooth module

Bluetooth Module• Must be able to send and receive messages from the

access point• Must communicate with the access point wirelessly• Must interface directly to the Microcontroller

DEC 0905 6

Functional Requirements (2)

Microcontroller Units• Must be able to receive commands from the

Bluetooth module • Must be able to send status messages to the

Bluetooth dongle• Must be able to control the device• Must be able to parse and interpret commands

Client Interface• 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

DEC 0905 7

Non-Functional Requirements

• GUI must have an intuitive look and feel for the user

• Wireless antennas must be internal or shorter than 4 inches

• Access point must have a footprint of less than 50 feet

DEC 0905 8

Market and Literature Survey

Similar Systems• HAI products• Proliphix

Technologies• Wireless communication: Zigbee, Bluetooth.

WLAN• Security: AES, RSA, MD5• Microcontrollers: AtMega 128, Jennic, MIPS• Transceivers: Easy Bluetooth, LMX 9820, WT11,

WT12

DEC 0905 9

Deliverables• Server• User Interface• Device control Unit• Project Plan • Project Poster• Design Documents • Final Report

DEC 0905 10

Work Breakdown

DEC 0905 11

Resource RequirementItem Cost

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 $50

Total $ 172

DEC 0905 12

Project Schedule

DEC 0905 13

Risks

• Time management: All four team members are currently full time students

• Project Complexity: Lot of subsystems connected together that we have to figure out how would they communicate to each other

• New technologies: Deal with new hardware and software

DEC 0905 14

User Interface Description

DEC 0905 15

Server Connections

DEC 0905 16

Server Description

The server contains three components. The HTML website, JavaScript page handler, and the HTTP server.

• The HTML allows for an easy user interface.• JavaScript communicates with the server via AJAX• The server communicates with the devices via

Bluetooth

DEC 0905 17

Device Control Unit ( DCU )

• The Device Control Unit consists of the microcontroller and a Bluetooth module that is connected to it

• The Bluetooth Module: provide the microcontroller the ability to wirelessly communicate with Bluetooth dongle on the server side

• The Microcontroller: connected directly at the other end to the home appliance and is able to control that device

DEC 0905 18

Bluetooth Communication The Bluetooth dongle: connected on the server side The Bluetooth module: connected on the UART (Universal

Asynchronous Receiver / Transmitter) port of the microcontroller which is PORT D

This PORT has a UART transmit pin TX, a UART receive pin Rx and a power and ground pins

Bluetooth module sends data at 9600 baud rate and the microcontroller system clock runs at 4MHz, we had to calculate the baud rate register value to be 4M/9600/16 - 1 rounded to nearest integer

A specific protocol was setup for proper communication

Bluetooth Module

DEC 0905 19

• up: garage door is open • dn: garage door is closed

BT dongle BT module

BluetoothConnection

n

Device name (**)

ab

*

b s

* *

Request for command

Send device name {gd,th} for garage door and thermostat respectively

Request a universal action

Acknowledgement

Request action * = {o,c} for opening or closing the garage door respectively

Acknowledgement (command executed)

Request the current status of the garage door

Respond the with status ** = {up,dn} where

Microcontroller (STK300)

• The microcontroller: has 6 different ports with 10 pins each

• Port B is used to power up the garage door opener control circuit, and the control signal wire is as well connected on Pin 2 of Port B

• This pin can be programmed using AVR studio so it sends 5V signals to toggle the switch

20DEC 0905

Relay Circuit• Connected between the microcontroller and the garage door opener

• Takes 5V output from the microcontroller and switches 24V garage door motor

• Diode protects the microcontroller from back EMF

Relay

21DEC 0905

DEC 0905 22

IR Sensor• Used to detect the status of the garage door

• Range: 9cm to 90cm

•The sensor’s Voltage reference is connected to the Aref pin of the analog port and the sensor’s digital output is connected to ADC pin of the microcontroller

•The conversion is done programmatically

IR Sensor

DEC 0905 23

Test PlanSoftware Testing

• Unit testing: Isolate the smallest piece of a testable code and test it

• Regression testing: Re-run previously run test after modifying functionality

• End Product testing: All of the functional requirements would be tested at the very high level, using the user interface

• Non functional Software Testing

Usability testing: Usability testing depends on the user feedback regarding the user interface.

Hardware Testing

• Each hardware component would be tested as soon as we receive it

• Double check wired connection

• Double check components configuration

DEC 0905 24

Server Testing

•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

Server test outputServer Test Program

Hardware Testing

• 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

DEC 0905 25Bray’s Terminal Microcontroller

Testing

DEC 0905 26

Future WorkMore Devices with multiple

microcontrollers

Adding more security features

Adding user authentication and separation of device controls

DEC 0905 27

Final ThoughtsAllocating more resources to the

server

Being able to begin basic implementation during the planning stage

Understanding the scope of our project

DEC 0905 28

Any Questions?

InternetInternet