VOL. 2, NO. 1, January 2012 ISSN 2225-7217 ARPN Journal of Science and Technology

©2010-2012 ARPN Journals. All rights reserved

http://www.ejournalofscience.org 

12

Novel Mobile Detector Sensing Alarming and Reporting System

K.Mohan Dece

SRM University

Tkpt.mohan@gmail.com

ABSTRACT

The objective of the Novel Mobile Detector Sensing Alarming and Reporting System is to find the mobile phone in and around some distance in restricted areas such as prisons, Colleges, schools, hospitals, petrol bunk etc. When any one mobile is used in the prohibited place this Device will detect that mobile signal through the antenna. In that particular place when a mobile signal is received, the receiver in this device will receive the signal through the antenna. When mobile receive the signal at the particular place, the alarm makes the sound for indication of the mobile and one LED will glow for the indication then with this device GSM Module is attached to send the Short Message service (SMS) to the registered number in the microcontroller. This detector is used to detect the presence of mobile. When it detects any mobile, it gives a signal to the PIC16F877A microcontroller. The controller when receives this signal will turn ON the buzzer circuit and will also send the detected message to some particular mobile numbers via the GSM module. Also the information is displayed in the LCD module as “MOBILE DETECTED”. Keywords: Mobile detector, Mobile indicator, Mobile sniffer. 1. INTRODUCTION

Now days the most problem of world is unauthorized use of mobile phones in prohibited area like examination halls confidential rooms, prisons, Colleges, schools, hospitals, petrol bunk etc. Here I try to prohibit the unauthorized using of mobile phones. So I like to build a detector, that should sense the presence of an activated mobile phone in a particular distance and it should indicate by alarming. Also the information should display in the LCD module and send message to the authorized mobiles through GSM modem. The circuit can detect both incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. At the moment when the mobile detector detects a signal from an activated mobile phone, it starts alarming and the LED blinks and it is also indicated through the LCD display. The alarm continues until the signal transmission get off.

2. PROPOSED DESIGN The circuit can detect both incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the bug detects RF transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases.

An ordinary RF detector using tuned LC circuits is not suitable for detecting signals in the GHz frequency band used in mobile phones. The transmission frequency of mobile phones ranges from 0.9 to 3 GHz with a wavelength of 3.3 to 10 cm. So a circuit detecting gigahertz signals is required for a mobile detector.

Here the circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the mobile phone. The lead length of the capacitor is fixed as 18 mm with a spacing of 8 mm between the leads to get the desired frequency. The disk capacitor along with the leads acts as a small gigahertz

loop antenna to collect the RF signals from the mobile phone.

Op-amp IC CA3130 (IC1) is used in the circuit as a current-to-voltage converter with capacitor C3 connected between its inverting and non-inverting inputs. It is a CMOS version using gate-protected p-channel MOSFET transistors in the input to provide very high input impedance, very low input current and very high speed of performance. The output CMOS transistor is capable of swinging the output voltage to within 10 mV of either supply voltage terminal.

Capacitor C3 in conjunction with the lead inductance acts as a transmission line that intercepts the signals from the mobile phone. This capacitor creates a field, stores energy and transfers the stored energy in the form of minute current to the inputs of IC1. This will upset the balanced input of IC1 and convert the current into the corresponding output voltage.

Capacitor C4 along with high-value resistor R1, keeps the non-inverting input stable for easy swing of the output to high state. Resistor R2 provides the discharge path for capacitor C4. Feedback resistor R3 makes the inverting input high when the output becomes high. Capacitor C5 (47pF) is connected across ‘strobe’ (pin 8) and ‘null’ inputs (pin 1) of IC1 for phase compensation and gain control to optimize the frequency response.

When the cell phone detector signal is detected by C3, the output of IC1 becomes high and low alternately according to the frequency of the signal as indicated by LED1. This triggers monostable timer IC2 through capacitor C7. Capacitor C6 maintains the base bias of transistor T1 for fast switching action. The low-value timing components R6 and C9 produce very short time delay to avoid audio nuisance.

Assemble the cell phone detector circuit on a general purpose PCB as compact as possible and enclose in a small box like junk mobile case. As mentioned earlier, capacitor C3 should have a lead length of 18 mm with lead

VOL. 2, NO. 1, January 2012 ISSN 2225-7217 ARPN Journal of Science and Technology

©2010-2012 ARPN Journals. All rights reserved

http://www.ejournalofscience.org 

13

spacing of 8 mm. Solder the capacitor carefully in standing position with equal spacing of the leads. The response can be optimized by trimming the lead length of C3 for the desired frequency. The unit will give the warning

indication if someone uses mobile phone within the particular place.

U1

NE555

OUT3

RST4

VCC8

GN

D1

CV5

TRG2 THR6

DSCHG7

Q1BC548

R23.9k

R3

100k

R41M

C1

100nF poly

C2

220uF

100nF poly

C

L1

INDUCTOR

D1

LED

D2

DIODE

BT1

6V

LS1

BUZZER

1

2

PIC16F877A

RE1/WR/AN69

RC3/SCK/SC1L18

RD0/PSP019

RD1/PSP120

RD6/PSP629RD7/PSP730VSS31

RB7/PGD40

MCLR/VPP1

RA0/AN02

RA1/AN13

RA2/AN2/VREF-4

RA3/AN3/VREF+5

RA4/T0CLK1/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/RD/AN58

RD2/PSP221RD3/PSP322RC4/SD1/SDA23RC5/SD024RC6/TX/CK25RC7/RX/DT26RD4/PSP427RD5/PSP528

RE2/CS/AN710

VDD11

VSS12

OSC1/CLK113

OSC2/CLK014

RC0/T1OS015

RC1/T1OS1/CCP216

RC2/CCP117

RB6/PGC39

RB538

RB437

RB3/PGM36

RB235

RB134

RB0/INT33

VDD32

GNDVCC

VCCGND

TXDRXD

D0

D2D1

D4D3

D5

D7D6

RWEN

RS

Fig.1: Detector Circuit Attached With Microcontroller

C6

CAP

P2

CONNECTOR DB9

594837261

U6

DS232

T1 IN11

T1 OUT14

R1 IN13

R1 OUT12

C1+1

C1-3

T2 IN10

T2 OUT7

R2 IN8

R2 OUT9

C2+4

C2-5

V+2

V-6

GN

D15

VC

C16

C14

CAP

C13

CAP

TX TXDRXRXD

C5

CAP

VCC

Fig. 2: RS 232

3. RESULTS

This paper Novel Mobile Detector Sensing alarming and Reporting System discussed about the detection of mobile phone in the Prohibited areas, this device is the advanced version of the mobile sniffer. But with the improvement in technology new areas are emerging in the detection techniques can be utilized for

handling detection of mobile phone in the places like prison and other places the detection of mobile phone in the switched off mode t are to be discuss in future

This poject won Cii innovator award 2011, SRM Innominds award 2010, Indian youth Science congess –Best innovation award 2010 and presented at Indian Science congress 2011 at SRM University.

VOL. 2, NO. 1, January 2012 ISSN 2225-7217 ARPN Journal of Science and Technology

©2010-2012 ARPN Journals. All rights reserved

http://www.ejournalofscience.org 

14

The real picture of the Device is as follows.

Fig. 3: Original Prototype

REFERENCES [1] Mobile Phone Sniffer track down mobile phones using this handy directional finder Design by B. Kainka. [2] Applying Packets Sniffer by Ghossoon. M. W. Al-Saadoon College of Administrative Sciences, Applied Science Ass. Prof. Manager Center of D&R for Lecturer Staff , University, Kingdom of Bahrain ,Manama.