30-05-2012, 03:25 PM
please collect information about this topic
30-05-2012, 03:25 PM
please collect information about this topic
24-09-2012, 02:20 AM
i want the documentation of dtmf based door locking system
25-09-2012, 10:09 AM
DTMF BASED DOOR LOCKING SYSTEM DTMF Based DOOR LOCKING doc.doc (Size: 877.5 KB / Downloads: 68) ABSTRACT Scope: The security system of home is an important issue to the public. We develop a low cost home security system that is widely employed in our daily life. This system is designed to prevent the opening of the door by the unauthorized persons. The structure of the home security system contains a door latch opener and a GSM mobile for the security dial up interfaced to the microcontroller. As soon as user dials the mobile the door lock opens. The controller maintains the decision with the received signal from the mobile then it opens the door latch. When an unauthorized person tries to open the door forcibly there will be a buzzer indication. The GSM modem (In Mobile) uses the UART interface through DTMF IC to the controller. This project is more helpful in the order of security purposes and this is a unique prototype project for enhancing the security systems. The microcontroller used in this project is the 8051 which is provided with the inbuilt EEPROM to store the password and the mobile number POWER SUPPLY SECTION: In-order to work with any components basic requirement is power supply. In this section there is a requirement of two different voltage levels. Those are 1) 5V DC power supply. 2) 9V DC power supply. Now the aim is to design the power supply section which converts 230V AC in to 5V DC. Since 230V AC is too high to reduce it to directly 5V DC, therefore we need a step-down transformer that reduces the line voltage to certain voltage that will help us to convert it in to a 5V DC. Considering the efficiency factor of the bridge rectifier, we came to a conclusion to choose a transformer, whose secondary voltage is 3 to 4 V higher than the required voltage i.e. 5V. For this application 0-9V transformers is used, since it is easily available in the market. The output of the transformer is 9V AC; it feed to rectifier that converts AC to pulsating DC. As we all know that there are 3 kind of rectifiers that is 1) half wave 2) Full wave and 3) Bridge rectifier Here we short listed to use Bridge rectifier, because half wave rectifier has we less in efficiency. Even though the efficiency of full wave and bridge rectifier are the same, since there is no requirement for any negative voltage for our application, we gone with bridge rectifier. Since the output voltage of the rectifier is pulsating DC, in order to convert it into pure DC we use a high value (1000UF/1500UF) of capacitor in parallel that acts as a filter. The most easy way to regulate this voltage is by using a 7805 voltage regulator, whose output voltage is constant 5V DC irrespective of any fluctuation in line voltage. SELECTION OF GSM MOBILE: GSM (Global System for Mobile communications) is an open, digital cellular technology used for transmitting mobile voice and data services. Here we are using it only for transmitting and receiving the messages. GSM wireless data module is used for remote wireless applications, machine to machine or user to machine and remote data communications in many applications. SELECTION OF DTMF RX IC: The MT8870D/MT8870D-1 is a complete DTMF receiver integrating both the bandsplit filter and digital decoder functions. The filter section uses switched capacitor techniques for high and lowgroup filters ; the decoder uses digital counting techniques to detect and decode all 16 DTMF tonepairs into a 4-bit code. External component count is minimized by on chip provision of a differential input amplifier , clock oscillator and latched three-state bus Interface SELECTION OF MOTOR: Stepper Motor is widely used in CNC machine drives , robots, and wherever an accurate positioning is required . In such applications, step angle , direction , operating modes( single coil or double coil), speed and position are important considerations. stepper motor is a simple dc motor with a permanent magnet rotor and a stator with armature consisting of coils. These coils produce a magnetic field when suitable current flows through them this field produces a torque in the rotor which makes it rotate.Well these are a little more complicated to control than the simple DC motors but these provide exact step wise rotation with an overall turn of 1.8 degrees / step . The step wise motion can be easily controlled by a stepper controller which is a simple circuit which takes digital logic and then uses it to turn the motor step wise . SELECTION OF LCD: A liquid crystal display (LCD) is an electronically-modulated optical device shaped into a thin, flat panel made up of any number of color or filled monochrome pixels with liquid crystals and arrayed in front of a light source(backlight) or reflector. In this project l LCD is used to display the GSM status. CIRCUIT OPERATION: In this application we are using mobile phones. To this mobile we are connecting one head set . This head set output is connected to DTMF RX IC & This is connected to one microcontroller and after that microcontroller connected to the stepper motor through the L293D DRIVER IC.In this application we are connecting one door type device to stepper motor. Here the operation is we are calling to the target mobile . then the mobile release some dual tone multiple frequencies. These frequencies are received by the DTMF RX IC and it converted to binary data. And It received by the microcontroller and then it can do particular operation depending upon the binary information. then controller can turn the motor to open the door as well as close the door by pressing the keys on the keyboard. INTRODUCTION TO EMBEDDED SYSTEMS Embedded systems are electronic devices that incorporate microprocessors with in their implementations. The main purposes of the microprocessors are to simplify the system design and provide flexibility. Having a microprocessor in the device helps in removing the bugs, making modifications, or adding new features are only matter of rewriting the software that controls the device. Or in other words embedded computer systems are electronic systems that include a microcomputer to perform a specific dedicated application. The computer is hidden inside these products. Embedded systems are ubiquitous. Every week millions of tiny computer chips come pouring out of factories finding their way into our everyday products. Embedded systems are self-contained programs that are embedded within a piece of hardware. Whereas a regular computer has many different applications and software that can be applied to various tasks, embedded systems are usually set to a specific task that cannot be altered without physically manipulating the circuitry. Another way to think of an embedded system is as a computer system that is created with optimal efficiency, thereby allowing it to complete specific functions as quickly as possible. Embedded systems designers usually have a significant grasp of hardware technologies. They use specific programming languages and software to develop embedded systems and manipulate the equipment. When searching online, companies offer embedded systems development kits and other embedded systems tools for use by engineers and businesses. Embedded systems technologies are usually fairly expensive due to the necessary development time and built in efficiencies, but they are also highly valued in specific industries. Smaller businesses may wish to hire a consultant to determine what sort of embedded systems will add value to their organization.
04-10-2012, 07:01 PM
do u have ppt on this topic?
if u have please post here..
05-10-2012, 12:05 PM
to get information about the topic "dtmf based door locking system" full report ppt and related topic refer the link bellow
https://seminarproject.net/Thread-docume...ing-system
01-11-2012, 11:50 AM
DTMF BASED DOOR LOCKING SYSTEM
DTMF BASED DOOR LOCKING.doc (Size: 26 KB / Downloads: 23) Aim: The main aim of the project is to build the DTMF based Door Locking system. Scope: The security system of home is an important issue to the public. We develop a low cost home security system that is widely employed in our daily life. This system is designed to prevent the opening of the door by the unauthorized persons. The structure of the home security system contains a door latch opener and a GSM mobile for the security dial up interfaced to the microcontroller. As soon as user dials the mobile the door lock opens. The controller maintains the decision with the received signal from the mobile then it opens the door latch. When an unauthorized person tries to open the door forcibly there will be a buzzer indication. The GSM modem uses the UART interface through DTMF IC to the controller. This project is more helpful in the order of security purposes and this is a unique prototype project for enhancing the security systems. The microcontroller used in this project is the 8051 which is provided with the inbuilt EEPROM to store the password and the mobile number. |
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