14-11-2012, 02:57 PM
A MOBILE-BASED HOME AUTOMATION SYSTEM
A MOBILE-BASED HOME AUTOMATION.pdf (Size: 523.38 KB / Downloads: 467)
ABSTRACT
The rapidly advancing mobile communication
technology and the decrease in costs make it possible to
incorporate mobile technology into home automation
systems. We propose a mobile-based home automation
system that consists of a mobile phone with Java
capabilities, a cellular modem, and a home server. The
home appliances are controlled by the home server,
which operates according to the user commands
received from the mobile phone via the cellular modem.
In our proposed system the home server is built upon an
SMS/GPRS (Short Message Service/General Packet
Radio Service) mobile cell module and a microcontroller,
allowing a user to control and monitor any
variables related to the home by using any java capable
cell phone. This paper presents the design and
implementation of AT modem driver, text based
command processing software, and power failure
resilient output for a microcontroller to facilitate in
sending and receiving data via the cell module,
together with the design of java application to enable
the cell phone to send commands and receive alerts
through the cell module.
INTRODUCTION
The explosive growth in cellular mobile
communications in the recent decade is changing the
way people live and work. With the rapid development
of mobile communication technology, a mobile phone
is evolving from a wireless device for voice only
communications to a truly portable personal terminal
for data communications and networking. Mobile
handsets today are essentially handheld computers with
integrated mobile radio communication capabilities.
The handsets allow users to download and run
applications. This opens the door for introducing a vast
variety of functionalities to the mobile phone and
making the mobile a real intelligent device.
The problem this paper looks at is, in general a mobilebased
remote control system for controlling and
monitoring of machine and devices at any time from
anywhere within the coverage of cellular mobile
networks. A typical application of such system is home
automation.
GRAPHICAL USER INTERFACE FOR MOBILE
PHONE
Java Application
The mobile phone is the interface between the user and
the home automation system. It has two tasks: 1)
providing a user-friendly interface for the user to input
control commands and view system’s feedback; 2)
sending user commands to and receiving system’s
feedback from the home server.
Today’s mobile phones have more processing power,
color screen, and are capable of running external
applications developed by users. These capabilities
make mobile phone an ideal platform for providing an
excellent user interface. A Java-enabled mobile phone
is chosen in our design due to the portability of Java
and the fast increasing popularity of Java-enabled
mobiles. The portability of Java ensures that
applications developed in Java language are portable
across different mobiles from different manufacturers.
Since Java has a rich library of application program
interfaces (API) providing functions such as graphical
user interface, sending and receiving SMS messages,
and communicating via GPRS, etc., Java applications
for mobile phones can be easily developed by using
Java development tools commonly known as
development environment. In addition, most mobile
phone manufactures provide their respective handset
emulators for developers to test their applications on
before testing on real phones.
Software Design
The software runs on the microcontroller and is an
integral part of the home server. It handles the
communication to and from the cellular modem, the
communication to the attached external control devices,
the processing of SMS messages, and the sending of
responses to commands/errors or alerts.
At startup, the software initializes the home server
system. The first of these is to setup the device to their
last state before power was lost, which is performed by
saving any changes in device state on the
microcontroller’s on-board data flash whenever any
change to the data state is made and so the system is
made resilient to short term power failure. The cellular
modem also needs to be setup to send and receive SMS
messages, this is done by sending the AT commands
specified to perform this task according to the GT48
AT datasheet [11], to the cellular modem via the RS232
port and waiting for the cellular modems
acknowledging reply.
CONCLUSION
The design and implementation of a novel mobilebased
home automation system is presented. The design
consists of a mobile phone with Java applications, a
cellular modem, and a microcontroller. The home
appliances are controlled by the microcontroller, which
operates according to the user commands received from
the mobile phone via the modem. Such a design
transforms a mobile phone into a portable remote
controller for home automation. It is noted that the
proposed system is not restricted to home automation, it
can be applied directly to remote control of many
industrial devices.