WIRELESS DOOR LOCKING

SHAILENDRA SINGH CHAUHAN, GAURAV KUMAR,

SUMIT SIWACH, VINAY RANJAN JAISWAL

DEPARTMENT OF MECHANICAL ENGINEERING

SIKKIM MANIPAL INSTITUTE OF TECHNOLOGY

MAJHITAR, SIKKIM, INDIA

Abstract:

Nowadays everything is moving from manual to automatic so it is necessary to develop door locking device involving some electronic component and mechanical mechanism.The wireless locking system works on single slider crank mechanism and performs the operation locking of door, vaults, etc. This system can be remotely controlled by RF module (Radio Frequency) and DTMF (Dual Tone Multi Frequency). The whole prototype in controlled by ATMEGA-8 microcontroller for controlling the opening or closing of the door. This mechanism (single slider crank mechanism) is highly efficient and economical as it uses only one motor and crank slider mechanism is made up of wood which is not so costly. The main objective of the project is to reduce human effort to remotely control the opening and closing of a simple gate.

Keywords: Four Bar Linkage, Grashof Condition, Motors, Transmitter and Receivers, DTMF Module, AVR Controller Board, L239D motor driving IC.

2.Introduction

As human race is reaching new heights people are evolving too with it in every field from technology to the way of living. Thus, wireless technology is one of most advancing areas in 21^st century. As people around the globe are getting caught up in the busy schedule so they want their way of living to reach new heights and experience new inventions and gadgets that could make their live cozy and comfortable. People tends to get annoyed by constant knocking on the door while sleeping especially in hostels, so one of our senior advised us to make some kind of automated mechanism for opening and closing of door. Keeping this thought in mind we put our minds together to bring up a new advancement in the field of wireless technology by bringing up wireless locking system. The whole system consists of first inversion of four bar mechanism that is single slider crank mechanism and some electrical components.IN this project we use RFID technology, radio frequency identification is a fundamental and inexpensive technology that enables wireless data transmission. When we press the button 1 on RFID Module the gate locks itself, while when we press button 2 on the RFID Module the gate unlocks itself and finally when the button 3 is pressed, the operation of the motor controlling the motion of the locking system, stops.

3.Mechanism

The mechanism consist of first inversion of four bar mechanism that is it is a single slider crank mechanism. The slider consists of two rods which performs to and fro motion for locking and unlocking the door. The whole mechanism is powered by a six rpm, six volt DC gear motor and so designed to transform rotational motion of motor into translational motion by means of single slider crank machanism.this mechanism is first inversion of four bar linkage.

2.1 Four Bar Linkage: A four bar link mechanism or linkage is the most fundamental of the plane kinematics linkages. It is a much preferred mechanical device for the mechanization and control of motion due to its simplicity and versatility. Basically it consists of four rigid links which are connected in the form of a quadrilateral by four pin joints. A link that makes complete revolutions is the crank, the link opposite to the fixed link is the coupler and the fourth link a lever or rocker if oscillates or an another crank, if rotate.

Fig 2.1: Four Bar Linkage

2.2 Planar Four Bar Linkage:Planar four-bar linkages are constructed from four links connected in a loop by four one degree of freedom joints. A joint may be either a revolute that is a hinged joint, denoted by R, or a prismatic, as sliding joint, denoted by P.A link connected to ground by a hinged joint is usually called a crank. A link connected to ground by a prismatic joint is called a slider. Sliders are sometimes considered to be cranks that have a hinged pivot at an extremely long distance away perpendicular to the travel of the slider. The link that connects two cranks is called a floating link or coupler. A coupler that connects a crank and a slider, it is often called a connecting rod.

There are three basic types of planar four-bar linkage depending on the use of revolute or prismatic joints:

1. Four revolute joints: The planar quadrilateral linkage is formed by four links and four revolute joints, denoted RRRR. It consists of two cranks connected by a coupler.

2. Three revolute joints and a prismatic joint: The slider-crank linkage is constructed from four links connected by three revolute and one prismatic joint, or RRRP. It can be constructed with crank and a slider connected by the connecting rod. Or it can be constructed as a two cranks with the slider acting as the coupler, known as an inverted slider-crank.

3. Two revolute joints and two prismatic joints: The double slider is a PRRP linkage. This linkage is constructed by connecting two sliders with a coupler link. If the directions of movement of the two sliders are perpendicular then the trajectories of the points in the coupler are ellipses and the linkage is known as an elliptical trammel, or the Trammel of Archimedes.

2.3 First Inversion of Four Bar:First inversion (Reciprocating engine and compressor) – this inversion is obtained when link 1 is fixed and links2 and 4 are made the crank and the slider respectively.

2.4 Grashof Condition

VARIABLES	DIMENSIONS
Crank	6.8 cm
Connecting rod	15.2 cm
Stroke length	5 cm
Forward stroke angle	15⁰
Return stroke angle	55⁰

The Grashof condition for a four-bar linkage states: If the sum of the shortest and longest link of a planar quadrilateral linkage is less than or equal to the sum of the remaining two links, then the shortest link can rotate fully with respect to a neighboring link. In other words, the condition is satisfied if -

S+L ≤ P+Q (1)

Here S is the shortest link, L is the longest, and P and Q are the other links

[
Fig 2.1:-linkage mechanism Table 2.1: Dimensions of Links

Motors

Fig 3.1: DC Gear Motor

DC motor is used in this project as actuator. The rotary motion of the motor is converted to linear motion by means of single slider crank mechanism. Again by changing the direction of current by microcontroller rotation direction of motor is changed .thus it locks the door for one direction of current decided by the microcontroller and unlock for opposite direction.

These motors, like any other electrical motor, use the magnetism induced by an electric current to rotate a rotor that is connected to a shaft .As we know that a coil of wire with current running through it generates an electro-magnetic field aligned with the center of coil, these fields generated transfer energy from the rotor to the shaft of each motor respectively. In a gear motor, the energy output is then used to turn a series of gear of the motor in an integrated gear train.

There are various types of motors but the most common motors generally in terms of use are the AC gear motors and the DC gear motors (AC for alternating current, DC for direct current respectively).

Transmitter and Receivers

Fig 4.1: Transmitter and receiver

A " 434MHZ RF 4CH " wireless remote control was operated as a transmitter and also as a receiver. This device is a two module-a transmitter and receiver. Together they make an addressable wireless system that can range up to 65 meters .This RF module used is compatible to HT12D/12E standards.

4.1 Transmitter: - transmitter of wireless remote control is a powerful transmitter module based on CMOS technology. There is an internal calibrated crystal oscillator in module HT12E .This module has 18 pin encoder IC [HT12E], with which the pin female connector compatible with 12DRF transmitter antenna is connected and one 8 bit address selected is connected and one 8 bit address select gives us the option of isolation the communication between the transmitter and the receiver module 4 bit data is available for providing input to the encoder I.C. On board we have a L7808 voltage regulator that regulates the voltage ranging from 3V -24 V.

4.2 Receiver end: - receiver of wireless remote is a powerful transmitter module base on CMOS technology. There is an internal calibrated crystal oscillator in module IC HT 12D, so there is no need to provide crystal oscillator externally.

This module has 18 pin decoder IC (HT12D), with which 8 pin female connector compatible with 12DRF receiver antenna is connected and 8 bit address select is connected. 8 bit address select gives us the option of isolating the communication between the transmitter and the transmitter and the receiver module.4 bit data pins data pins are given for data output . One LED is connected to denote valid transmission.

DTMF Module

Fig 5.1: DTMF Module

DTMF module version (RM0033) decodes DTMF signal either from an audio source or phone line to 4 bit binary, TTL (SV) level output. It also indicates output with LED. It can be used with microcontrollers develop various DTMF related applications like remote control, caller ID, Auto Dialer. This module can be easily be used in conjunction with any of the robosapien development boards and develop mobile operated robots and gadgets.

Highly accurate filter circuits are implemented to divide tone signals into high frequency and low frequency signals. Basically it is an 18 pin IC. The HT9170 series consist of band pass filters and two digital decoder circuits to convert a tone DTMF signal into some signal output. It has a built-in amplifier circuit to adjust the input signals. The pre-filter circuit may filter out the dialing tone of 350Hz to 400Hz signal, and then use the high-pass and low-pass filters to split into high and low frequency signals. When the HT9170 receives an effective tone (DTMF) signal. The DV pin goes high and tone code (DTMF) signal is transferred to its internal circuit for decoding after setting the OE pin goes high and the DTMF decodes will appear on pin D0-D3. A standard 3.579545MHz connected to X1 and X2 terminals implement the oscillatory function.

AVR Controller Board

Fig 6.1: AVR Controller Board

AVR Controller Board is a complete starter kit and development system for the AVR Atmega16/32/8535 microcontrollers from ATMEL ® Corporation. It is designed to give designers a quick start to develop code on the AVR.AVR Development Board kit is based on our 40 pin development board which is compatible with many of the Atmel AVR microcontrollers. This kit is an easy and low cost way to get started with microcontrollers. Included on board is an Atmega16/32/8535 microcontroller, external crystal with supporting capacitors, AVCC filter parts, Power supply parts and more. The Controller used is an 8-bit microcontroller. The versatility of board helps us to avail Programmable 16KB of flash, 1KB of RAM and Accessible 24C x I2C EEPROM. The board has 32 I/O lines, one programmable full duplex USART, 4 PWM channels and 8 channel 10-bit ADC Converter. The board create a perfect platform for operating dual 8-bit Timers each having separate pre-scalars and compare modes. Additionally, a single 16-bit timer with a separate pre-scalar, compare and capture mode can be used. The Atmega16/32 is a feature packed and very versatile microcontroller. The board takes Input which can be either analog or Digital in nature. On board we have PIN extensions of all the parallel I/O line available with the micro controller to make the peripherals plug n play.

Two L293D ICs are also available in Atmega-16/32 development board to run 4 different motors simultaneously. There is 1 DB-9 female connecter also mounted on board for PC connection. There is one 16 pins LCD connector (female) also available. There are four PWM channels also available by which we can control stepper/servo motors. Master/Slave SPI serial interface availability make use of USBASP programmer to flash program in controller.8 keypad switch and pattern of 8 different lids are also available on Atmega-16 board. There are two different option to provide power supply (DC battery/adapter) to the development board. It also has 4 Interrupt switches to create interrupts.

7. Program Code

#include<avr/io.h>

int main(void)

{

int d=0;

int b=0;

DDRB=0b11111111; //PORTB as output Port connected to motors

DDRD=0b00000000; //PORTD Input port connected to RFID module

while(1) // infinite loop

{ d=PIND&0b11111111;

//PORTB=0b11111111;

if(d==0b00000001) //if Key 1 is pressed

{

PORTB=0b00000001;

}

if(d==0b00000010) // if Key 2 is pressed

{

PORTB=0b00000010;

}

if(d==0b000000011) // if Key 3 pressed

{

PORTB=0b00000000;//

}

} //while closed

} //main closed

8.Flow Chart

9. Future Prospective

Hydraulic technology can be used in near future for smoother operation.
IR Sensors can be used to make it fully automated.
Password protection can be used to make it effective for home security.
The design of this project can also be replaced by Biometric finger print device.

10. Conclusion

This project is a working state of art developing technology in the field of wireless automatic systems. The unmanned system and wireless controls helps in saving time and human power. However the range of RF module is limited only up to 65metres only so it cannot be controlled from distance. It has wider use that is it can be used in home, factory and for lockers with password protection. This projects is certainly a boon for the lazy people.

Fig 10.1: Working Wireless Door Locking System

Fig 10.2: 3D VIEW

Fig 10.2: Front view

Fig 10.3:TOP VIEW

Fig 10.4: SIDE VIEW

11. Acknowledgement

It is my pleasure to take this opportunity to thank all those who helped me directly or indirectly in successfully making this project. Not everything that I have learned can be acknowledged with a few words, not everything that I acknowledge will relieve me from my indebt-ness.

I am grateful to Mr. Dheeraj Kumar, Assistant Professor, Department of Mechanical engineering, Sikkim Manipal Institute of Technology for his patience, motivation, enthusiasm, immense knowledge and constant support. His guidance has helped me throughout my project work and in writing my paper.

I would like to extend my sincere thanks to Mr. Dhruva Kumar, Assistant Professor, Department of Mechanical engineering, Sikkim Manipal Institute of Technology for constantly motivating us and helping us out selflessly.

I would like to thank all my friends and especially my classmates for all the discussions and helping us out with programing. We are especially indebted to our parents for their love, sacrifice, and support. Our full dedication to the work would have not been possible without their blessings and moral support. This project is a dedication to them.

12. References

Journal Papers:

[1] Zeydin pala and Nihat Inan ,”smart parking application using RFID Technology”, RFID Eurasia, 1^st annual in RFID Eurasia, 2007

[2] Goodrum, P. Mclarem, M.Durfee “ The Application of Active Radio Frequency Identification Technology for Tour Tracking on Contruction job Sites” Automation in Construction, 15 (3), 2006, pp 292-302

Books:

[1]Theory of Machines by SS Ratan

Web Support:

[1] Robomart (http://www.robomart.com)

[2] Robosapiens (https://robosapi.com)

[3] Electroncomponents (http://www.electroncomponents.com)

[4] Frontiers in Robotics Automation and Control – Alexander Zemliak