A Cell Phone-Based Remote Home Control System

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A Cell Phone-Based Remote Home Control System
Adam Mohling CprEmohbandy_at_iastate.edu
Issa Drame EEissad_at_iastate.edu
Chau Nguyen EEchayman_at_iastate.edu
Arturo Palau EEapalau_at_iastate.edu
Advisor Ahmed E. Kamal, Professorkamal_at_iastate.e
du
Client ECpE Department
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Agenda

• Problem statement
• System overview
• System components
• Technology considerations
• Device operations
• Summary and conclusions
• Questions

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Problem Statement

• Design a system that allows users, upon
  authentication, to remotely control and monitor
  multiple home appliances using a cell phone-based
  interface.

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Project in Action Entire System
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Project in Action Cellular Phone Communication
Controlled Devices
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Cellular Phone Communication

• Technologies Considered
• Tone Decoding (DTMF) Features
• High Compatibility with all cell phone models
• Limited user interaction
• More prone to user error (uneditable)
• Inefficient, time consuming
• Additional hardware required (convert sound to
  binary)
• Text Messaging (SMS) Features
• Data transmitted in binary form (ASCII)
• Message can be edited prior to sending

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Cellular Phone Communication

• Technology Selected Text Messaging
• Reasons for Selection
• Allows user to verify and edit the message before
  sending to ensure the command issued is the
  command requested
• Data is transmitted in binary, requires less
  hardware to manipulate (as opposed to DTMF)
• Most commonly used in M2M technology

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Cellular Phone Communication

• Text Message Implementation
• Users will be provided with a list of pre-defined
  commands that can be stored into the cellular
  phone
• Users will then have to enter or issue the
  commands from the cellular phone defined by the
  command list
• Example command PASSWORD

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Project in Action Cellular Module
Controlled Devices
Text Messages
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Cellular Modules
Model Type Connection type Programming Additional features Kit SIM
EE54 Edge GSM / GPRS USB 2.0 Low insertion force system connector AT commands (GSM07.07 and 07.05) TCP/IP protocol stack. PPP protocol Required 1.8/3V on board SIM card reader
GM47 GSM / GPRS 60 pin board-on-board including RS232 for AT 2 general purpose Serial interfaces AT proprietary commands AT access to TCP/IP stack UDP Required 3/5V SIM reader with SIM detection
GM28 GSM / GPRS RS232 DB-9 connection Control via AT commands AT access to TCP/IP stack UDP UCS2 16 bit data supported Not Required 3/5V SIM reader with SIM detection
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Cellular Modules

• Module Selected GM28
• Reasons for Selection
• RS232 DB9 connector
• No kit necessary for interface
• Located coding examples

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Project in Action - Microcontroller
GM28
Controlled Devices
Text Messages
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Microcontrollers
Starter Kit STK200 Starter Kit STK300 Starter Kit Freescale Starter Kit MC68HC11E9 8051 Starter Kit Philips XA/RD/66x
Microcontroller AT90S8515(8K bytes Flash) ATmega128(128KB Flash 4KB EEPROM 4KB SRAM) MC68HC11E9 (12KB Flash/EPROM 512B RAM 512B EEPROM) XA-G49 (64KB Flash 2KB RAM)
Cable/Connection ISP and RS232 ISP and RS232 opt. USB PC COM port RS232
Power Consumption 9-15VDC or 7-12VAC 9-15VDC or 7-12VAC 7-18VDC 9-15V AC or DC
I/O 64-pins 66-pins 38 pins 32 pins
Highlights     Sockets for various microcontrollers Vcc and Ground for powering external circuitry 3"x1.5" Solderless Breadboard 40-pin DIP
Highlights     Vcc and Ground for external circuitry Include daughter board 32Kbytes external RAM 44-pin PLCC sockets
Highlights     Brownout (2.9V or 4.5V level) Brownout (2.9V or 4.5V level) Buffalo Monitor utility for debug and test program switches and 10-way Bar LED
Software     Application Builder STK300 Application Builder AXIDE Application Builder
Software     AVR Studio 3 and 4 AVR ISP (C-complier) free Assembler, C compiler C-compiler Demos
Software     AVREdit and AVRGCC AVR and IAR Studio   WINISP and Flash Magic Programming Tools
Price 66 85 99 94.80
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Microcontroller

• Microcontroller Selected STK300 Starter Kit
• Reasons for Selection
• Allows large-scaled projects (ATmega128)
• Interchangeable microcontroller design
• Sufficient number of I/O pins
• Vcc and Gnd pins can power external circuitry
• Application Builder, AVR Studio, and programmable
  in C Language

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Programming Languages Considered

• All the software developed for this project will
  be loaded into the memory of the STK300
  microcontroller.
• The language must be supported by the STK300s
  compiler
• The STK300 compiler supports C and Assembly
• Java and C considered because code can be
  converted to C
• Assembly C
• C Java

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Development Languages

• Development Language Considered
• Assembly Language Features
• Low level language (greater device control)
• Less memory required
• Not many development resources/libraries
  available
• Team out of practice in Assembly language
  programming

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Development Languages

• Development Language Considered
• JAVA Language Features
• Many GSM programming resources available
• Object oriented language (modular coding)
• Large memory requirement
• Poor response time

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Development Languages

• Development Language Considered
• C Language Features
• All team members have knowledge of C
• Object oriented language (modular coding)
• Not many development resources / libraries
  available

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Development Languages

• Development Language Considered
• C Language Features
• Universally reliable language
• Many programming resources available
• Serial port libraries
• GSM libraries
• Example code and project resources online
• Team will need to identify differences between C
  and C

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Development Languages

• Development Language Selected C Programming
  Language
• Reasons for Selection
• Vast amount of online resources
• Ease of development
• Team members have experience coding C

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Software Development Environment

• The code for this project will be developed in a
  more user friendly environment than AVR Studio
  (provided with the STK300)
• Possible Solutions
• Eclipse v3.1
• MS Visual Studio .NET 2003

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Software Development Environment

• Eclipse v3.1
• Free, but requires some setup for team
• MS Visual Studio .NET 2003
• Free through MSDNAA (available to all ECE)
• Both are similar in their advantages. Since the
  .c files will be copied into the STK300s
  compiler, decision was made to go with Visual
  Studio .NET

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Project in Action Controlled Devices
GM28
STK300
Controlled Devices
Text Messages
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Controlled Devices

• The following devices will be controlled by the
  microcontroller
• Fan
• Light
• Digital thermostat

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Controlled Devices - Fan
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Controlled Devices - Light
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Controlled Device Status Detection
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Controlled Device - Digital Thermostat
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Summary

• Experiences
• Technical Experiences
• GSM modules
• Microcontroller
• Control circuits synthesis
• Personal Experiences
• Time management
• Communication
• Accountability

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Conclusions

• Lessons Learned
• Functioning in a team environment
• Should follow assignment criteria closely
• Amount of detailed documents goes in a
  professional project

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Acknowledgements

• Special thanks to Sony Ericsson for providing the
  teams GM28 cellular module
• Special thanks to Prof Kamal for his continued
  support to the team

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Questions?
GM28
Any device with an electrical interface
STK300
Controlled Devices
Text Messages
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Issues Addressed

• Authentication and User Interaction
• Submit password with text message every time
  action requested
• Open sessions by submitting session open/close
  text message
• One-time password authentication via text message
• Create a Java GUI (for cell phone) that will
  address user interactions

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Password For Every Action

• For every action requested, a user password is
  required
• PRO
• Increased security - user guaranteed authentic by
  system every time
• All commands issued will have the same format of
  command password
• CON
• Requires user to enter password every time
• More work for user, possible user error
• Ex.) parsed by (what if user enters
  in message?)

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Open and Close Sessions

• User submits an open/close session command.
  Acceptance allows phone to submit requests until
  session times out or is closed by user.
• PRO
• Less overhead for user
• Authentication only once
• CON
• Overload system with too many sessions
• What if user phone lost?
• What if user phone dies (session never closed)

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One Time Password Authentication

• User submits an authentication command. Upon
  being confirmed, phone number added to an
  acceptable user list and any message sent from
  this number is accepted.
• PRO
• Less overhead for user
• Authentication only once
• CON
• Security issue
• What if user phone lost?
• What if others identify password

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Java GUI for Cellular Phone

• Team creates a Java GUI for the cellular phone
  that will provide user with a menu of acceptable
  commands
• PRO
• Less overhead for user
• User error virtually eliminated
• CON
• What if user phone lost?
• Limited phone type compatibility
• Phone requires more than simple text messaging
  capability
• Increased cost for users
• Pay for internet service to download/install Java
  app (if required)