18-10-2016, 04:12 PM
Feasibility Study of Implementation of Cell Phone Controlled, Password Protected Door Locking System
1459706708-3Feasibility.pdf (Size: 1.02 MB / Downloads: 66)
ABSTRACT: This article summarizes the use of DTMF signalling technology to send and receive the control
commands from user in order to open or close the door. Password protection is given to the system with help of
microcontroller and corresponding algorithm that authenticate the user by checking the password provided by the user.
So, if and only if the user press correct password then only user get authenticate and gets the access to open or close the
door. Above said work has been examined theoretically as well as practically in this article. The feasibility of
implementation is examined with the help of simulator which would indicate the real time results of system mentioned
here.
INTRODUCTION
The main objective of this system is to unlock a door by a mobile phone using a unique code entered through the
keypad of the phone. Opening and closing of doors involves human to be physically involved in to the task. In this cell
phone controlled, password protected door locking system, the opening and closing of a door is achieved by using a
mobile phone. The owner can call to a mobile phone stacked to the system which in turn is connected to the door motor
that can open/close the door by entering the password. This method is very convenient as one doesn‟t have to get down
of his car to open/close the door physically [6]. The cell phone in the system is kept in auto answer mode. So, after a
ring the cell phone accepts the call and starts voice transmission. Now for the button pressed, the DTMF tones are fed
to the circuit and the corresponding actions are performed [1]. As interest in wireless communication continues to
grow, the remote controlled systems are increasingly being integrated into everyday life. The results of this integration
are end-users possessing less and less technical knowledge of the technology. For example, consider the application of
mobile robots in the health care industry, where the intended end users are patients themselves. In this case, the need
for simplified, reliable, and user-friendly robot designs is of almost importance.
Mobile phones today became very popular an essential entity for one and all and so, for any mobile based
application there is great reception. Wireless controlled systems utilize RF circuits. However, the use of RF contributes
to enhancing the already mysterious nature of communication strategies, which had limitations like limited range,
limited frequency ranges and controls. But a mobile phone controlled systems can hold up these limitations. It has a
robust control, unlimited range (coverage area of the service provider), and we can have as much as 12 controls.
II. LITERATURE SURVEY
The DTMF technology is associated with digital telephony and provides two selected o/p frequencies (One high
band and one low band). The DTMF technique consist of 16 common alphanumeric characters (0-9, A-D, *, #) on the
telephone. Each characters is uniquely referenced by selecting one of the four low band frequencies associated with the
matrix rows, coupled with selecting one of the four high band frequencies associated with the matrix columns [
Corresponds to each character, there is unique tone frequency given by,
x(t) = A cos (ωt) + B cos (ωh t+ φ)
Where ωl and ωh are the low and high frequencies of the sine waves being used, A & B are the amplitude of the
signals and φ is the initial phase shifts.
[2] Presented an idea to water irrigation in the smart farm using DTMF communication and live video transmission
of process parameter. This paper summarizes the controlled irrigation system in the Indian agriculture segment. The
idea suggested here is based on cell phone controlled water management system in which a user can make a video call
to the cell phone placed at farm site called as a receiver. Receiver mobile is kept in auto answer mode; it will accept the
call and starts the video transmission. During the course of call if user pushes any button, corresponding Dual Tone
Multi Frequency (DTMF) will be send to receiver mobile. That DTMF received at receiver is fed to microcontroller via
DTMF decoder IC. Microcontroller is pre programmed to take any decision for corresponding key such as turn
ON/OFF the pump, rotate the camera to see the status of soil etc. So this is the simple farm water management system
which can be controlled by farmer from any place and avoid lot of efforts.
This work can be extended to control the home appliances such as A.C, Fan, Refrigerator, T.V, Heater, Washing
machine and even a door also. So motivated from this background this system have been implemented and the results
are verified with small model to open and close the door with password protection.
III. THE CELL PHONE CONTROLLED, PASSWORD PROTECTED DOOR LOCKING SYSTEM
This work is based on the concept of DTMF (dual tone multi – frequency) technology. All numeric button on the
keypad of a mobile phone generates a unique frequency when pressed. These frequencies are decoded by the DTMF
decoder IC at the receiving end which is fed to the microcontroller. If this decoded values i.e. code pressed by user
matches with the password stored in the microcontroller, then the microcontroller initiates a mechanism to open the
door through a motor driver interface
The user in order to open the door should make a voice call to the phone which is stacked with the controller unit
acting as receiver mobile. This receiver mobile is kept in auto answer mode. So after a ring it will automatically accept
the call. Now if user press any button on keypad of phone, the tone corresponds to that button is sent to other end. This
tone is fed to DTMF Decoder, where the DTMF frequency is converted in to the equivalent digital form. For example,
if 2 is pressed on the keypad, the output of the decoder will be 0010. This digital information is given to the
microcontroller. The Microcontroller is pre-programmed to take decision corresponds to input button pressed. A 16x2
LCD display is interfaced with the control unit to display instructions to user. Depending upon the user password,
controller will decide to open/close the door if the user get authenticate, by using relay drive circuit and motor.
IV.CIRCUIT DIAGRAM
Fig. 2 illustrates the actual circuit that has been used to obtain the working model of cell phone controlled, password
protected door locking system. It consists of Microcontroller, Inverter, motor driver ckt and the DTMF Decoder.
Initially microcontroller accepts binary input from DTMF decoder MT8870 (Not shown in circuit diagram).
Corresponding to the received tone, microcontroller takes decision to turn motor clockwise or anticlockwise to
OPEN/CLOSE the door respectively