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TRAINING PROJECT REPORT University Institute of Engineering & Technology 2 Acknowledgment It is my privilege to express my sincerest regards to my project coordinator, Mr. Manish Kumar and Mr. Ashok Kumar, for their valuable inputs, able guidance, encouragement, whole-hearted cooperation and constructive criticism throughout the duration of our project. I deeply express my sincere thanks to my Head of Department Mr. Anil Kumar for encouraging and allowing me to present the project on the topic “Password Door Lock” at our department premises for the partial fulfilment of the requirements leading to the award of B-Tech degree. I take this opportunity to thank all my lecturers who have indirectly helped my project. I pay my respect and love to my parents for their love and encouragement throughout my career. Last but not the least I express my thanks to my friends for their cooperation and support. Abhishek Verma 3 Certificate This is to certify that Abhishek Verma of University Institute of Engineering and Technology, Chandigarh, has successfully completed a project on “Password Door Lock” during 6 weeks summer training at National Institute of Technical Teachers Training and Research, Chandigarh. This report has not been submitted to any other Organisation and does not form part of any Course undergone by then, for the award of BTech Degree. Head of Department (ESC) Er. Anil Kumar 4 Table of Contents 1. Type of Electronic Components………………………………………………...……….5 1.1 Active………………………………………………………………………………...5 1.2 Passive………………………………………………………...……………………..5 2. Battery……………………………………………………………………..…………….5 2.1 Lead Acid……………………………………………………………………...…….5 2.2 Lithium Ion………………………………………………………………………..…5 3. Resistor ………………………………………………………………………………….5 4. Capacitor……………………………………………………………………….….……..6 5. Inductor…………………………………………………………………….…….………6 6. Transformer……………………………………………………………………….……..7 7. Rectifier…………………………………………………………………………….……7 7.1 Half wave rectifier……………………………………………………………….…..7 7.2 Full wave rectifier……………………………………………………………….…...8 7.3 Bridge rectifier…………………………………………………………………….…8 8. Electronic voltage regulators………………………………………………………….…9 9. Regulated power supply…………………………..…………………………………....11 10.Transistor……………………………………..………………………………………...13 11.Relay…………………………………………………………………………..………..14 12.Optocoupler……………………………………………………………….……………16 13.The combined circuit of relay and optocoupler………………………………….……..18 14.Dual Power supply………………………………………………………….…………..19 15.Password Door Lock Project……………………………………………………….......23 15.1 Description……………………………………………………………….………..23 15.2 Components used………………………………………………………….………23 15.3 Source code………………………………………………………………..………27 15.4 Precautions…………………………………………………………………..….…31 15.5 Recommendations…………………………………………………………….......31 5 1. Type of Electronic Components 1.1. Active: The devices or components which require external source for their operation. These components produce energy in the form of voltage or current. These components have gain greater than or equal to 1. Example: transistors, vacuum tubes, thyristors, diodes (except rectifier diode) 1.2. Passive: Passive Components do not require external source for their operation. These components store or maintain energy in the form of voltage or current. These components do not have any gain. Example: resistors, capacitors, inductors 2. Battery It provides the mentioned voltage difference which is supplied to the circuit. 2.1. Lead Acid: Requires charge and discharge cycle. It provides higher power than lithium ion batteries. 2.2. Lithium Ion: Once charged, the charge can be stored for a longer time, i.e. there is no immediate need of using up the stored charge. Power is low but can be increased by using series and parallel combination of batteries. 3. Resistor A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. Resistors act to reduce current flow, and at the same time, act to lower voltage levels within circuits. In electronic circuits, resistors are used to limit current flow, to adjust signal levels, bias active elements, terminate transmission lines among other uses. High-power resistors that can dissipate many 6 watts of electrical power as heat may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity. [1] To find value of a resistor refer Fig.1. Fig.1 to find value of a resistor 4. Capacitor A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field The forms of practical capacitors vary widely, but all contain at least two electrical conductors (plates) separated by a dielectric (i.e. an insulator that can store energy by becoming polarized). The conductors can be thin films, foils or sintered beads of metal or conductive electrolyte, etc. The nonconducting dielectric acts to increase the capacitor's charge capacity. A dielectric can be glass, ceramic, plastic films, air, vacuum, paper, mica, oxide layer etc. Capacitors are widely used as parts of electrical circuits in many common electrical devices. Unlike a resistor, an ideal capacitor does not dissipate energy. Instead, a capacitor stores energy in the form of an electrostatic field between its plates. [1] 5. Inductor An inductor, also called a coil or reactor, is a passive two-terminal electrical component which resists changes in electric current passing through it. It consists of a conductor such as a wire, usually wound into a coil. When a current flows through it, energy is stored temporarily in a magnetic field in the coil. When 7 the current flowing through an inductor changes, the time-varying magnetic field induces a voltage in the conductor, according to Faraday’s law of electromagnetic induction, which opposes the change in current that created it. As a result, inductors always oppose a change in current, in the same way that a flywheels opposes a change in rotational velocity. Care should be taken not to confuse this with the resistance provided by a resistor. An inductor is characterized by its inductance, the ratio of the voltage to the rate of change of current, which has units of henries (H). [1] 6. Transformer A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Commonly, transformers are used to increase or decrease the voltages of alternating current in electric power applications. [1] A varying current in the transformer's primary winding creates a varying magnetic flux in the transformer core and a varying magnetic field impinging on the transformer's secondary winding. This varying magnetic field at the secondary winding induces a varying electromotive force (EMF) or voltage in the secondary winding. Making use of Faraday's Law in conjunction with high magnetic permeability core properties, transformers can thus be designed to efficiently change AC voltages from one voltage level to another within power networks. [1] Rating is mentioned on transformer .For example, if written 9:230 can be deciphered as 9V is the voltage given and 230V is the voltage obtained. 7. Rectifier 7.1 Half Wave Rectifier Theory In half wave rectification of a single-phase supply, either the positive or negative half of the AC wave is passed, while the other half is blocked. Because only one half of the input waveform reaches the output, mean voltage is lower. Half-wave rectification requires a single diode in a single-phase supply, or three in a three-phase supply. Rectifiers yield a unidirectional but pulsating direct current; half-wave rectifiers produce far more ripple than full-wave rectifiers, and much more filtering is needed to eliminate harmonics of the AC frequency from the output. [4] Circuit Diagram 8 Fig.2 Half Wave Rectifier 7.2 Full Wave Rectifier Theory Full wave rectifier rectifies the full cycle in the waveform i.e. it rectifies both the positive and negative cycles in the waveform. Full wave rectifier has an advantage over the half wave rectifier i.e. it has average output higher than that of half wave rectifier. The number of AC components in the output of the full wave rectifier is less than that of the input. [4] Circuit diagram Fig.3 Full Wave Rectifier 7.3 Bridge Rectifier Theory In bridge rectifier four diodes are used. These are connected as shown in the circuit diagram. The four diodes are connected in the form of a bridge to the transformer and the load as shown. In first half cycle of the AC input, the upper portion of the transformer secondary winding is positive with respect to the lower portion. Thus during the first half cycle diodes D1 and D4 are forward biased. Current flows through path 1-2, enter into the load RL. It returns back flowing through path 4-3. During this half input cycle, the diodes D2 and D3 are reverse biased. Hence there is no current flow through the path 2-3 and 1-4. During the next cycle lower portion of the transformer is positive with respect to the upper portion. Hence during this cycle diodes D2 and D3 are forward biased. Current flows through the path 3-2 and flows back through the path 4-1.The diodes D1 and D4 are reverse biased. So there is no current flow through the path 1-2 and 3-4.Thus negative cycle is rectified and it appears across the load. [4] 9 Circuit diagram Fig.4 Bridge Rectifier TABLE I Components Specification required Capacitor No. of components required 150uf,470uf,1000uf,0.5W 3 Diode Resistance Battery Transformer 0.7V (threshold voltage) 1k, 1.5k 12Vdc 230:9 4 2 1 1 Observation TABLE II Capacitance/voltage Voltage peak to peak, Vp-p Average Voltage, Vav RMS Voltage, Vrms 150uf 3.250V 470uf 212mV 1000uf 128.1mV 10.20V 11.63V 11.67V 10.20V 11.63V 11.67V 8. Electronic voltage regulators A simple voltage regulator can be made from a resistor in series with a diode (or series of diodes). Due to the logarithmic shape of diode V-I curves, the voltage across the diode changes only slightly due to changes in current drawn or changes in the input. When precise voltage control and efficiency are not important, this design may work fine. 10 Circuit diagram Fig.5 Voltage Regulator using Zener Diode The voltage regulator is of two types- 1. Positive Voltage Regulator (7805) It outputs a positive constant voltage. The xx in 78xx indicates the fixed output voltage it is designed to provide. 7805 provides +5V regulated power supply. The pinout of 7805 is as follows. TABLE III Pin no. 1. 2. 3. Function Input voltage(7V18V) Ground(0V) Regulated output, 5V Name Input Ground Output 2. Negative Voltage Regulator (7905) It outputs a negative constant voltage. The xx in 79xx indicates the fixed output voltage it is designed to provide. 7905 provides -5V regulated power supply. The pinout of 7905 is as follows. TABLE IV Pin no. Function Name 11 1. 2. 3. Ground(0V) Ground Input Input voltage(7V-18V) Regulated output, Output -5V 9. Regulated power supply A regulated power supply can convert unregulated ac (alternating current or voltage) to a constant dc (direct current or voltage). A regulated power supply is used to ensure that the output remains constant even if the input changes. The regulated power supply will accept an ac input and give a constant dc output. Circuit Diagram Fig.6 Regulated power supply The basic building blocks of a regulated dc power supply are as follows: 1. A step down transformer 2. A rectifier 3. A DC filter 4. A regulator Operation of Regulated Power Supply Step Down Transformer A step down transformer will step down the voltage from the ac mains to the required voltage level. The turn’s ratio of the transformer is so adjusted such as to obtain the required voltage value. The output of the transformer is given as an input to the rectifier circuit. 12 Rectification Rectifier is an electronic circuit consisting of diodes which carries out the rectification process. Rectification is the process of converting an alternating voltage or current into corresponding direct (dc) quantity. The input to a rectifier is ac whereas its output is dc. A bridge rectifier is used to rectify both the half cycles of the ac supply (full wave rectification). DC Filteration The rectified voltage from the rectifier is a pulsating dc voltage having very high ripple content. But this is not we want, we want a pure ripple free dc waveform. Hence a RC filter is used. As the instantaneous voltage starts increasing the capacitor charges, it charges till the waveform reaches its peak value. When the instantaneous value starts reducing the capacitor starts discharging exponentially and slowly through the load. Hence, an almost constant dc value having very less ripple content is obtained. Regulation This is the last block in a regulated DC power supply. The output voltage or current will change or fluctuate when there is change in the input from ac mains or due to change in load current at the output of the regulated power supply or due to other factors like temperature changes. This problem can be eliminated by using a regulator. A regulator will maintain the output constant even when changes at the input or any other changes occur. . IC 7805 is used to obtained fixed values of voltages at the output. Usually, coupling capacitors of values about 0.01µF to 10µF needs to be connected at the output and input to address input noise and output transients. Application of Regulated Power Supply Regulated power supply is the main component of electrical, electronics and as well as automation equipment. Mobile phone charger, oscillator, amplifier all need the regulated power supply to function. [3] Observations The waveform smoothened with the application of capacitor at the output. Result A DC wave of 5V was obtained at the output. 13 10. Transistor Theory Transistors are current controlled solid state devices that conduct current in proportion to an input current. For an NPN transistor, current flowing into the base of the transistor results in proportionally larger current to flow between the collector and emitter. Similarly, for a PNP transistor, current flowing out of the base of the transistor results in proportionally larger current to flow between the collector and emitter. Circuit diagram Fig.7 Transistor TABLE V Components required Battery Base resistance Collector resistance Potentiometer Transistor Specification No. components required 12V dc 1 Green blue 1 brown,560 ohms Brown black 1 red,1kohms 1kohms 1 BC547 1 of Observations TABLE VI State of Transistor Off On Voltage difference across base and emitter 0V 0.8V Result By adjusting the knob of the transistor the transistor switches its state from off to on. 14 11. Relay A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays. Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits as amplifiers: they repeated the signal coming in from one circuit and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations. [1] Solid-state relays control power circuits with no moving parts, instead using a semiconductor device to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults; in modern electric power systems these functions are performed by digital instruments still called "protective relays".[1] Relay circuit with BJT (BC547) Circuit Diagram Fig.8 Relay circuit with BJT TABLE VII Components required Specification Battery Potentiometer Relay 12V dc 10k HRS4HSDC12V green 560ohms(1), 1kohms(2) 0.7V (threshold voltage) BC547 LED Resistance Diode BJT No. of components required 1 1 1 2 3 1 1 15 OBSERVATION TABLE VIII Relay terminals Voltage difference between base and emitter Normally closed Normally open 0.003 V 0.768 V Result By adjusting the knob of the potentiometer the relay switched from NC to NO so the led glowed alternatively. Relay circuit with MOSFET (IRF840) CIRCUIT DIAGRAM Fig.9 Relay circuit with MOSFET TABLE IX Components required Battery Potentiometer Relay LED Resistance Diode MOSFET OBSERVATION Specification 12V dc 10k HRS4HS-DC12V No. of components required 1 1 1 2 3 560ohms(1), 1kohms(2) 0.7V (threshold 1 voltage) IRF840 1 16 TABLE X Relay terminals Normally closed Normally open V across base emitter 2.5 V 4.12 V Result By adjusting the knob of the potentiometer the relay switched from NC to NO so the LEDs glowed alternatively 12. Optocoupler In electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal. A common type of opto-isolator consists of an LED and a phototransistor in the same opaque package. Usually opto-isolators transfer digital (on-off) signals, but some techniques allow them to be used with analog signals. [1] An opto-isolator contains a source (emitter) of light, almost always a near infrared light-emitting diode (LED), that converts electrical input signal into light, a closed optical channel (also called dielectrical channel), and a photosensor, which detects incoming light and either generates electric energy directly, or modulates electric current flowing from an external power supply. The sensor can be a photoresistor, a photodiode, a phototransistor, a silicon-controlled rectifier (SCR) or a triac. Because LEDs can sense light in addition to emitting it, construction of symmetrical, bidirectional opto-isolators is possible. An optocoupled solid state relay contains a photodiode opto-isolator which drives a power switch, usually a complementary pair of MOSFETs. A slotted optical switch contains a source of light and a sensor, but its optical channel is open, allowing modulation of light by external objects obstructing the path of light or reflecting light into the sensor. [1] Circuit diagram Fig.10 Optocoupler 17 TABLE XI COMPONENTS SPECIFICATION NO. OF COMPONENETS Opto coupler 4N35 1 Potentiometer 10k 1 Voltage LM7805 1 regulator Resistance 1k 2 Observation TABLE XII Measurements Base emitter voltage Emitter base voltage Collector current value 0.448V 0.458V +-50mA Result By adjusting the knob of the potentiometer the led was switching its state from on to off. 13. The combined circuit of relay and optocoupler Theory When the input voltage is applied to the optocoupler it turns the transistor ON. This happens when the transistor inside optocoupler drives the other transistor to saturation state which results in shifting the mechanical arm through magnetized inductor coil from NC to NO. When the applied power supply is removed then the magnetized inductor coil in relay will demagnetize through freewheeling diode and the mechanical arm shifts back to NO. Circuit diagram 18 Fig.11 The combined circuit of relay and optocoupler TABLE XIII Components required Specification Battery Potentiometer Relay 12V dc 10k HRS4HSDC12V LED Resistance Diode Fet Optocoupler Voltage regulator Resistance 560ohms(1), 1kohms(2) 0.7V (threshold voltage) BC547 4N35 LM7805 1k No. of components required 1 1 1 3 3 1 1 1 1 2 Observations TABLE XIV Result State of optocoupler State of Relay Off On Normally Connected Normally Open 19 By adjusting the knob of the potentiometer the optocoupler switches its state from off to on and correspondingly the relay switches from normally connected to normally open. 14 .Dual Power supply Theory The circuit given here is of a regulated dual power supply that provides +5V and -5V from the AC mains. A regulated power supply is used to ensure that the output remains constant even if the input changes. The regulated power supply will accept an ac input and give a constant dc output. The basic building blocks of a regulated dc power supply are as follows: 1. A step down transformer 2. A rectifier 3. A DC filter 4. Two regulators Circuit diagram Fig.12 Dual Power supply Operation of Regulated Dual Power Supply Step Down Transformer A step down transformer will step down the voltage from the ac mains to the required voltage level. The turn’s ratio of the transformer is so adjusted such as to obtain the required voltage value. The output of the 20 transformer is given as an input to the rectifier circuit. Rectification Rectifier is an electronic circuit consisting of diodes which carries out the rectification process. Rectification is the process of converting an alternating voltage or current into corresponding direct (dc) quantity. The input to a rectifier is ac whereas its output is dc. A bridge rectifier is used to rectify both the half cycles of the ac supply (full wave rectification). DC Filtration The rectified voltage from the rectifier is a pulsating dc voltage having very high ripple content. But this is not we want, we want a pure ripple free dc waveform. Hence a RC filter is used. As the instantaneous voltage starts increasing the capacitor charges, it charges till the waveform reaches its peak value. When the instantaneous value starts reducing the capacitor starts discharging exponentially and slowly through the load. Hence, an almost constant dc value having very less ripple content is obtained. Regulation This is the last block in a regulated dual DC power supply. The output voltage or current will change or fluctuate when there is change in the input from ac mains or due to change in load current at the output of the regulated dual power supply or due to other factors like temperature changes. This problem can be eliminated by using a regulator. A regulator will maintain the output constant even when changes at the input or any other changes occur.IC 7805 and 7905 are used for the purpose of voltage regulation in which the former is a positive 5V regulator and later is a negative 5V regulator. The output of 7805 will be +5V and that of 7905 will be -5V.Usually coupling capacitors of values about 0.01µF to 10µF needs to be connected at the output and input to address input noise and output transients. Application of Regulated Power Supply A power supply like this is a very essential tool on the work bench of an electronic hobbyist. Regulated dual power supply is the main component of electrical, electronics and as well as automation equipment. [3] Observations 1. Wave smoothens with the application of capacitor at the output of voltage regulator. 2. Wave approaches a DC wave as the value of capacitance increases. Result A DC wave of +5V and -5V is observed at the output of 7805 and 7905 respectively. 21 Fig13 Regulated power supply circuit on breadboard and initial waveform Fig.14 Waveform across 780 Fig.15 Waveform across 7905 Fig.16 Voltage across resistor parallel to 7805 22 Fig.17 Voltage across resistor parallel to 7905 Fig.18 Voltage across capacitor before 7805 Fig.19 The wave smoothens as the value of capacitor increases 23 15. Project Title-Password door lock using 8051 microcontroller: 15.1 Description A 4x3 matrix keypad and a 16x2 LCD have been used here. Keypad and LCD are very commonly used input & output devices, respectively. A five digit predefined password needs to be specified by the user. This password is stored in the system. While unlocking, if the entered password from keypad matches with the stored password, then the lock opens and a message is displayed on LCD. The motor first rotates in clockwise direction, then stops for a while and then rotates in anticlockwise direction for same time period. The connections in the circuit are as following: port P2 of microcontroller AT89C51 is used as data input port which is connected to data pins (7-14) of LCD. P0^7, P0^6 and P0^5 pins of microcontroller are connected to control pins RS, RW and EN of LCD. Port P3 is used to take input from keypad. P1^0,P1^1 have been used as lock output pin of controller.P1^2 has been connected to red LED which glows when gate is closed and P1^3 has been connected to green LED which glows when gate is open. As the program starts, string ‘Enter Password’ is displayed on LCD. The keypad is scanned for pressed digits one by one. Every time, row and column of the key pressed is detected and a ‘*’ is displayed on LCD corresponding to the entered number. After the five digits are entered, if the passwords do not match, a message is displayed to indicate ‘Access Denied’; otherwise a message is displayed to indicate ‘Access Granted’ and the gate opens for a specified period of time. And the loop continues. 15.2 Components used TABLE XV Sr.No. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Name of Component AT89C51 Microcontroller 40 pin IC Base L293D IC Driver 16 pin IC Base 16x2 LCD Preset Crystal Oscillator 12MHz Resistor 10kΩ Resistor 1kΩ Capacitor 33pF Capacitor 10uF Red LED No. of Components 1 1 1 1 1 1 1 1 2 2 1 1 24 13. 14. 15. 16. 17. 18. 19. 20. Green LED DC Motor Voltage Regulator 7805 Push Button Batteries 9V SIP PCB Board Connecting Wires 1 1 1 13 2 1 1 As per Requirement AT89C51 Fig.20 AT89C51 AT89C51 is an 8-bit microcontroller and belongs to Atmel's 8051 family. ATMEL 89C51 has 4KB of Flash programmable and erasable read only memory (PEROM) and 128 bytes of RAM. It can be erased and program to a maximum of 1000 times. In 40 pin AT89C51, there are four ports designated as P1, P2, P3 and P0. All these ports are 8-bit bi-directional ports. Except P0 which needs external pull-ups, rest of the ports have internal pull-ups. When 1s are written to these port pins, they are pulled high by the internal pull-ups and can be used as inputs. These ports are also bit addressable and so their bits can also be accessed individually. Port P0 and P2 are also used to provide low byte and high byte addresses, respectively, when connected to an external memory. Port 3 has multiplexed pins for special functions like serial communication, hardware interrupts, timer inputs and read/write operation from external memory. AT89C51 has an inbuilt UART for serial communication. It can be programmed to operate at different baud rates. Including two timers & hardware interrupts, it has a total of six interrupts. [2] Preset 25 Fig.21 Preset A preset is a three legged electronic component which can be made to offer varying resistance in a circuit. The resistance is varied by adjusting the rotary control over it. The adjustment can be done by using a small screw driver or a similar tool. The resistance does not vary linearly but rather varies in exponential or logarithmic manner. Such variable resistors are commonly used for adjusting sensitivity along with a sensor. The variable resistance is obtained across the single terminal at front and one of the two other terminals. The two legs at back offer fixed resistance which is divided by the front leg. So whenever only the back terminals are used, a preset acts as a fixed resistor. Presets are specified by their fixed value resistance. [2] LCD Fig.22 16x2 LCD LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments and other multi segment LEDs. The reasons being: LCDs are economical; easily programmable; have no limitation of displaying special & even custom characters (unlike in seven segments), animations and so on. A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. In this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers, namely, Command and Data. The command register stores the command instructions given to the LCD. A command is an instruction given to LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc. The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD. [2] Software: We have implemented the circuit in Proteus software and program in embedded C language in Keil software for simulation before implementing the circuit on breadboard. The hex file was loaded into the microcontroller using Wilpro software.The PCB Design has been done using ORCAD software. 26 Fig.23 Circuit Diagram in Proteus Fig.24 Password Door Lock implemented on breadboard 27 15.3 Source code #include <reg51.h> #define DATA P2 void lcd_init(void); void lcd_cmd(unsigned char); void lcd_display(unsigned char); void Key_Scan(void); void DelayMs(int); void rr(); void ww(); sbit motor1=P1^0; sbit motor2=P1^1; sbit red=P1^2; sbit green=P1^3; sbit RS = P0^7; sbit RW = P0^6; sbit lcd_e = P0^5; unsigned char R,C,ch,d=0xC1; unsigned int i=0; unsigned char Key[4][3] = {'1','2','3', // KEYPAD '4','5','6', '7','8','9', '*','0','#'}; code unsigned char msg[] = (" ENTER PASSWORD"); code unsigned char msg1[]= (" ACCESS GRANTED"); code unsigned char msg2[]= (" ACCESS DENIED"); unsigned char arr[5]; unsigned char car[5]={'1','2','3','4','5'}; void main() // MAIN PROGRAM { int z,u; u=0; motor1=0;motor2=0;red=1;green=0; lcd_init(); DelayMs(1); lcd_e=0; lcd_cmd(0xC0); for(z=0;z<5;z++) { Key_Scan(); DelayMs(1); ch=Key[R][C]; arr[u]=ch; DelayMs(1); lcd_display('*'); lcd_cmd(d++); DelayMs(10); 28 P3=0xFF; u++; } if(arr[0]==car[0]) { if(arr[1]==car[1]) { if(arr[2]==car[2]) { if(arr[3]==car[3]) { if(arr[4]==car[4]) { rr(); } else { ww(); } } else { ww(); } } else { ww(); } } else { ww(); } } else { ww(); } DelayMs(1); } void Key_Scan(void) { unsigned int i = 0; P3 = 0x0F; while(P3 == 0x0F); if(P3 == 0x0E) // ACCEPT KEY 29 R = 0; else if(P3 == 0x0D) R=1; else if(P3 == 0x0B) R = 2; else if(P3 == 0x07) R = 3; P3 = 0xF0; while(P3 == 0xF0); if(P3 == 0xE0) C = 0; else if(P3 == 0xD0) C = 1; else if(P3 == 0xB0) C = 2; DelayMs(10); } void lcd_cmd(unsigned char cmnd) // LATCH COMMAND { DATA = cmnd; RS = 0; RW = 0; lcd_e = 1; DelayMs(1); lcd_e = 0; } void lcd_display(unsigned char dat) // LATCH DATA { DATA = dat; RS = 1; RW = 0; lcd_e = 1; DelayMs(1); lcd_e = 0; } void lcd_init(void) //INITIALISE LCD { unsigned char i; lcd_cmd(0x38); DelayMs(1); lcd_cmd(0x0E); DelayMs(1); lcd_cmd(0x01); DelayMs(1); lcd_cmd(0x80); DelayMs(1); i=0; 30 while(msg[i]!='\0') { lcd_display(msg[i]); i++; } DelayMs(1); } void rr() //DISPLAY "ACCESS GRANTED" { int t; lcd_cmd(0X01); DelayMs(1); t=0; while(msg1[t]!='\0') { lcd_display(msg1[t]); t++; } motor1=1; red=0; green=1; DelayMs(5); motor2=0;motor1=0; DelayMs(10); motor2=1; motor1=0; DelayMs(5); } void ww() //DISPLAY "ACCESS DENIED" { int g; lcd_cmd(0X01); DelayMs(1); g=0; while(msg2[g]!='\0') { lcd_display(msg2[g]); g++; } DelayMs(10); } void DelayMs(int k) //DELAY FUNCTION { unsigned int a,b; for(a=0;a<=k;a++) for(b=0;b<1275;b++); } //END OF PROGRAMME 31 15.4 Precautions 1. 2. 3. 4. Wires should be insulated properly in order to avoid short circuiting. Connections should not be loose. The supply to the driver IC should be provided separately to avoid overloading of voltage regulator. Care should be taken that the voltage supply to the microcontroller should not exceed 5 Volts. 15.5 Recommendations 1. Enter password when cursor starts blinking. 2. Enter inside in given time. 32 Future Work I will like to extend this project for real life. Sensors will be used to check wheatear a person has entered or not. Doors will only be closed after complete entry of individual. If due to some reasons door is not able to close after a given time then an alarm will be raised. The data of entry of an individual will be sent to a control room. Also I am thinking to add thumb scanner which will generate a different one time password for every different individual so as to make room highly secure. 33 List of Figures 1. To find value of a resistor 2. Half Wave Rectifier 3. Full Wave Rectifier 4. Bridge Rectifier 5. Voltage Regulator using Zener Diode 6. Regulated power supply 7. Transistor 8. Relay circuit with BJT 9. Relay circuit with MOSFET 10. Optocoupler 11. The combined circuit of relay and optocoupler 12. Dual Power supply 13. Regulated power supply circuit on breadboard and initial waveform 14. Waveform across 7805 15. Waveform across 7905 16. Voltage across resistor parallel to 7805 17. Voltage across resistor parallel to 7905 18. Voltage across capacitor before 7805 19. The wave smoothens as the value of capacitor increases 20. AT89C51 21. Preset 22. 16x2 LCD 23. Circuit Diagram in Proteus 24. Password Door Lock implemented on breadboard 34 List of Tables 1. Components used in rectifier 2. Observations of rectifier 3. Pinout of 7805 4. Pinout of 7905 5. Components used in experiment of transistor 6. Observations of transistor 7. Components used in experiment of relay with BJT 8. Observations of relay with BJT 9. Components used in experiment of relay with MOSFET 10. Observations of relay with MOSFET 11. Components used in experiment of optocoupler 12. Observations of optocoupler 13. Components used in experiment of combined circuit of relay and optocoupler 14. Observations of combined circuit of relay and optocoupler 15. Components used in project 35 References 1. www.wikipedia.com 2. www.engineersgarage.com 3. www.allaboutcircuits.com 4. www.electronicstutorial.com 5. www.google.com