INTRODUCTION

The utilization of electrical power progressively increases in now-a-days. The demand for the electrical power is also increases over the entire world, particularly in India the demand for electrical power increases more and more because of the increase in population. The people utilize the power higher than their requirements because of their sophisticated needs in the day to day life. The major part of electrical power is consumed by the urban areas than the rural areas .The people lived in the urban areas wants to make their life luxurious with the use of more power for their home appliances.

The power conservation is more important to reach the demand of the electrical power; there are several methods available for the conservation of electrical power.

Every system is automated in order to face new challenges in the present day situation. Automated systems have less manual operations, so that the flexibility, reliabilities are high and accurate. Hence every field prefers automated control systems. Especially in the field of electronics automated systems are doing better performance increasingly.

The use of modern technologies is to achieve the power conservation not only through the proper design of respective devices and other parameters in the power system. A major part of power conservation can be achieved by consumers proper usage of the power for home appliances, for this purpose CELL PHONE BASED DEVICE CONTROL WITH VOICEACKNOWLEDGEMENTis one of the optimal way .Which uses Mobile technology that keeps monitoring of the various appliances, and will control the operation of these appliances with respect to the signal sent by the mobile. For utilization of appliances the new concept has been thought to manage them remotely by using mobile, which enables the user to remotely control switching of domestic appliances. Just by dialling keypad of remote telephone, from where you are calling you can perform ON / OFF operation of the appliances.

The mobile communications has become one of the driving forces of the digital revolution. Every day, millions of people are making phone calls by pressing a few buttons. Little is known about how one person's voice reaches the other person's phone that is thousands of miles away. Even less is known about the security measures and protection behind the system. The complexity of the cell phone is increasing as people begin and digital pictures to their friends and family. The cell phone is slowly turning into handheld computer. All the features and advancements incell phonetechnology require a backbone to support it. The system has to provide security and the capability for growth to accommodate future enhancements.The main aim of our project is to operate our home appliances like lights and water pumpfrom office or any other remote places. So if we forgot to switch off the lights or other appliances while going out, it helps us to turn off the appliances with our cell phone. Cell phone works as the remote control for our home appliances. We can control the desire appliance by pressing the corresponding key. The system also gives us voice acknowledgement of the appliance status.

1.1 Hardware Specifications

VOLTAGE REGULATOR 7805

Features

Output Current up to 1A. Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V. Thermal Overload Protection. Short Circuit Protection. Output Transistor Safe Operating Area Protection.

Description:

The LM78XX/LM78XXA series of three-terminal positive regulators are available in the TO-220/D-PAK package and with several fixed output voltages, making them useful in a Wide range of applications. Each type employs internal current limiting, thermal shutdown and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output Current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents.

Figure 11 Circuit Diagram of Voltage Regulator

Internal Block Diagram

Figure 12 Block Diagram of Voltage Regulator

Absolute Maximum Ratings

Table 101 Ratings of the Voltage Regulator

BC547

TECHNICAL SPECIFICATIONS:

The BC547 transistor is an NPN Epitaxial Silicon Transistor. The BC547 transistor is a general-purpose transistor in small plastic packages. It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.

Figure 13 BC 547 Transistor Pinouts

We know that the transistor is a "CURRENT" operated device and that a large current (Ic) flows freely through the device between the collector and the emitter terminals. However, this only happens when a small biasing current (Ib) is flowing into the base terminal of the transistor thus allowing the base to act as a sort of current control input. The ratio of these two currents (Ic/Ib) is called the DC Current Gain of the device and is given the symbol of hfe or nowadays Beta, (). Beta has no units as it is a ratio. Also, the current gain from the emitter to the collector terminal, Ic/Ie, is called Alpha, (), and is a function of the transistor itself. As the emitter current Ie is the product of a very small base current to a very large collector current the value of this parameter is very close to unity, and for a typical low-power signal transistor this value ranges from about 0.950 to 0.999.

An NPN Transistor Configuration

Figure 14 Transistor Configuration

DTMF RECEIVER MT8870

The MT8870 is a complete DTMF receiver integrating both the bandsplit filter and digital decoder functions. The filter section uses switched capacitor techniques for high and low group filters; the decoder uses digital counting techniques to detect and decode all 16 DTMF tone-pairs 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.

Figure 15 Detailed Block Diagram Of MT8870

Applications: Repeater systems/mobile radio Credit card systems Remote control Personal computers Telephone answering machine

Benefits: Complete DTMF Receiver Low power consumption Internal gain setting amplifier Adjustable guard time Central office quality Power-down modePin Description:

Figure 16 Pin Diagram of MT8870 1. IN+Non-Inverting Op-Amp (Input).2. IN-Inverting Op-Amp (Input).3. GSGain Select.Gives access to output of front end differential amplifier for connection of feedback resistor.4. V-RefReference Voltage (Output).Nominally VDD/2 is used to bias inputs atmid-rail .5. INHInhibit (Input).Logic high inhibits the detection of tones representing characters A, B, C and D. This pin input is internally pulled down.6. PWDNPower Down (Input).Active high. Powers down the device and inhibits the oscillator. This pin input is internally pulled down.7. OSC1Clock (Input).8. OSC2Clock (Output). A 3.579545 MHz crystal connected between pins OSC1 and OSC2 completes the internal oscillator circuit.9. VSSGround (Input). 0 V typical.10. TOEThree State Output Enable (Input).Logic high enables the outputs Q1-Q4. This pin is pulled up internally.11-14. Q1-Q4Three State Data (Output).When enabled by TOE, provide the code corresponding to the last valid tone-pair received (see Table 1). When TOE is logic low, the data outputs are high impedance.15. StDDelayed Steering (Output).Presents a logic high when a received tone-pair has been registered and the output latch updated; returns to logic low when the voltage on St/GT falls below VTSt.16. EStEarly Steering (Output).Presents a logic high once the digital algorithm has detected a valid tone pair (signal condition). Any momentary loss of signal condition will cause ESt to return to a logic low.17. St/GTSteering Input/Guard time (Output) Bidirectional.A voltage greater than VTSt detected at St causes the device to register the detected tone pair and update the output latch. A voltage less than VTSt frees the device to accept a new tone pair. The GT output acts to reset the external steering time-constant; its state is a function of ESt and the voltage on St.18. VDDPositive power supply (Input). +5 V typical.

DTMF DECODER

In DTMF decoder circuit we use IC 8870. IC 8870 converts the dual tones to corresponding binary outputs.

DTMF SIGNALLING

Table 102 DTMF decoding

AC register signaling is used in DTMF telephones, here tones rather than make/break pulse are used for dialing, each dialed digit is uniquely represented by a pair of sine waves tones. These tones (one from low group for row and another from high group for column) are sent to the exchange when a digit is dialed by pushing the key, these tone lies within the speech band of 300 to 3400 HZ, and are chosen so as to minimize the possibility of any valid frequency pair existing in normal speech simultaneously. Actually, this minimisator is made possible by forming pairs with one tone from the higher group and the other from the lower of frequencies. A valid DTMF signal is the sum of two tones, one from a lower group ( 697-940 Hz) and the other from a higher group ( 1209-1663 Hz). Each group contains four individual tones. This scheme allows 10 unique combinations. Ten of these code represent digits 1 through 9 and 0. . tones in DTMF dialing are so chose that none of the tones is harmonic of are other tone. Therefore is no change of distortion caused by harmonics. Each tone is sent as along as the key remains pressed. The DTMF signal contains only one component from each of the high and low group. This significantly simplifies decoding because the composite DTMF signal may be separated with band pass filters into single frequency components, each of which may be handled individually.

31

MICROCONTROLLER ATMEGA8

Features

Figure 17 PIN configuration of microcontroller

High-performance, Low-power AtmelAVR 8-bit Microcontroller Advanced RISC Architecture 130 Powerful Instructions Most Single-clock Cycle Execution 32 8 General Purpose Working Registers Fully Static Operation Up to 16MIPS Throughput at 16MHz On-chip 2-cycle Multiplier High Endurance Non-volatile Memory segments 8Kbytes of In-System Self-programmable Flash program memory 512Bytes EEPROM 1Kbyte Internal SRAM Write/Erase Cycles: 10,000 Flash/100,000 EEPROM Data retention: 20 years at 85C/100 years at 25C Optional Boot Code Section with Independent Lock BitsIn-System Programming by On-chip Boot ProgramTrue Read-While-Write Operation Programming Lock for Software Security Peripheral Features Two 8-bit Timer/Counters with Separate Prescaler, one Compare Mode One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and CaptureMode Real Time Counter with Separate Oscillator Three PWM Channels 8-channel ADC in TQFP and QFN/MLF packageEight Channels 10-bit Accuracy 6-channel ADC in PDIP packageSix Channels 10-bit Accuracy Byte-oriented Two-wire Serial Interface Programmable Serial USART Master/Slave SPI Serial Interface Programmable Watchdog Timer with Separate On-chip Oscillator On-chip Analog Comparator Special Microcontroller Features Power-on Reset and Programmable Brown-out Detection Internal Calibrated RC Oscillator External and Internal Interrupt Sources Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, andStandby I/O and Packages 23 Programmable I/O Lines 28-lead PDIP, 32-lead TQFP, and 32-pad QFN/MLF Operating Voltages 2.7V - 5.5V (ATmega8L) 4.5V - 5.5V (ATmega8) Speed Grades 0 - 8MHz (ATmega8L) 0 - 16MHz (ATmega8) Power Consumption at 4Mhz, 3V, 25 degreeC

PROCESSOR

A processor is an electronic device capable of manipulating data in a way specified by a sequence of instructions.

INSTRUCTIONS

Instructions in a computer are binary numbers just like data. Different numbers, when read and executed by a processor, cause different things to happen. The instructions are also called opcodes or machine codes. Different bit patterns activate or deactivate different parts of the processing core. Every processor has its own instruction set varying in number, bit pattern and functionality.

PROGRAM

The sequence of instructions is what constitutes a program. The sequence of instructions may be altered to suit the application.

ASSEMBLY LANGUAGE

Writing and understanding such programs in binary or hexadecimal form is very difficult ,so each instructions is given a symbolic notation in English language called as mnemonics. A program written in mnemonics Form is called an assembly language program. But it must be converted into machine language for execution by processor.

Figure 18 Internal Block Diagram of ATMEGA8

ASSEMBLER

An assembly language program should be converted to machine language for execution by processor. Special software called ASSEMBLER converts a program written in mnemonics to its equivalent machine opcodes.

HIGH LEVEL LANGUAGE

A high level language like C may be used to write programs for processors. Software called compiler converts this high level language program down to machine code. Ease of programming and portability.

Pin Description:

Memory:It has8 Kbof Flash program memory (10,000 Write/Erase cycles durability),512 Bytesof EEPROM (100,000 Write/Erase Cycles).1KbyteInternal SRAM

I/O Ports:23 I/ line can be obtained from three ports; namely Port B, Port C and Port D.

Interrupts: Two External Interrupt source, located at port D. 19 different interrupt vectors supporting 19 events generated by internal peripherals.Timer/Counter:Three Internal Timers are available, two 8 bit, one 16 bit, offering various operating modes and supporting internal or external clocking.SPI (Serial Peripheral interface):ATmega8 holds three communication devices integrated. One of them is Serial Peripheral Interface. Four pins are assigned to Atmega8 to implement this scheme of communication.

USART:One of the most powerful communication solutions isUSARTand ATmega8 supports both synchronous and asynchronous data transfer schemes. It has three pins assigned for that. In many projects, this module is extensively used for PC-Micro controller communication.

TWI (Two Wire Interface):Another communication device that is present in ATmega8 is Two Wire Interface. It allows designers to set up a commutation between two devices using just two wires along with a common ground connection, As the TWI output is made by means of open collector outputs, thus external pull up resistors are required to make the circuit.Analog Comparator:A comparator module is integrated in the IC that provides comparison facility between two voltages connected to the two inputs of the Analog comparator via External pins attached to the micro controller.

Analog to Digital Converter:Inbuilt analog to digital converter can convert an analog input signal into digital data of10bitresolution. For most of the low end application, this much resolution is enough.

16*2 LCD DISPLAY HD44780

Figure 19 16*2 LCD DISPLAY

Features 5 * 8 and 5 * 10 dot matrix possible Low power operation support: 2.7 to 5.5V Wide range of liquid crystal display driver power: 3.0 to 11V Liquid crystal drive waveform: A (One line frequency AC waveform) Correspond to high speed MPU bus interface:2 MHz (when VCC = 5V) 4-bit or 8-bit MPU interface enabled: 80 *8-bit display RAM (80 characters max.) 9,920-bit character generator ROM for a total of 240 character fonts 208 character fonts (5 *8 dot) 32 character fonts (5 *10 dot)

DescriptionThe HD44780U dot-matrix liquid crystal display controller and driver LSI displays alphanumerics,Japanese kana characters, and symbols. It can be configured to drive a dot-matrix liquid crystal display under the control of a 4- or 8-bit microprocessor. Since all the functions such as display RAM, character generator, and liquid crystal driver, required for driving a dot-matrix liquid crystal display are internally provided on one chip, a minimal system can be interfaced with this controller/driver. A single HD44780U can display up to one 8-character line or two 8-character lines. The HD44780U has pin function compatibility with the HD44780S which allows the user to easily replace an LCD-II with an HD44780U. The HD44780U character generator ROM is extended to generate 208 5 *8 dot character fonts and 32 5* 10 dot character fonts for a total of 240 different character fonts. The low power supply (2.7V to 5.5V) of the HD44780U is suitable for any portable battery-driven product requiring low power dissipation.

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 overseven segmentsand other multi segmentLEDs. The reasons being: LCDs are economical; easily programmable; have no limitation of displaying special & evencustom characters(unlike in seven segments),animations and so on.

A16x2 LCDmeans 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. Click to learn more about internal structure of aLCD.

Pin Figure 110 Pin Diagram

Table 103 Pin DescriptionPin NoFunctionName

1Ground (0V)Ground

2Supply voltage; 5V (4.7V 5.3V)Vcc

3Contrast adjustment; through a variable resistor

VEE

4Selects command register when low; and data register when highRegister Select

5Low to write to the register; High to read from the registerRead/write

6Sends data to data pins when a high to low pulse is givenEnable

78-bit data pinsDB0

8DB1

9DB2

10DB3

11DB4

12DB5

13DB6

14DB7

15Backlight VCC(5V)Led+

16Backlight Ground (0V)Led-

RELAY

A relay is an electrically operated switch. Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. The coil current can be on or off so relays have two switch positions and they are double throw (changeover) switches. Relays allow one circuit to switch a second circuit which can be completely separate from the first. For example a low voltage battery circuit can use a relay to switch a 230V AC mains circuit. There is no electrical connection inside the relay between the two circuits; the link is magnetic and mechanical. The coil of a relay passes a relatively large current, typically 30mA for a 12V relay, but it can be as much as 100mA for relays designed to operate from lower voltages. Most ICs (chips) cannot provide this current and a transistoris usually used to amplify the small IC current to the larger value required for the relay coil. The maximum output current for the popular 555 timer IC is 200mA so these devices can supply relay coils directly without amplification. Relays are usually SPDT or DPDT but they can have many more sets of switch contacts, for example relays with 4 sets of changeover contacts are readily available. For further information about switch contacts and the terms used to describe them please see the page on switches. Most relays are designed for PCB mounting but you can solder wires directly to the pins providing you take care to avoid melting the plastic case of the relay.

Figure 111 Connection diagram of relay

The relay's switch connections are usually labeled COM, NC and NO: COM = Common, always connect to this; it is the moving part of the switch. NC = Normally Closed, COM is connected to this when the relay coil is off. NO = Normally Open, COM is connected to this when the relay coil is on. Connect to COM and NO if you want the switched circuit to be on when the relay coil is on. Connect to COM and NC if you want the switched circuit to be on when the relay coil is off. When anelectric currentis passed through the coil it generates amagnetic fieldthat activates the armature, and the consequent movement of the movable contact(s) either makes or breaks (depending upon construction) a connection with a fixed contact. If the set of contacts was closed when the relay was de-energized, then the movement opens the contacts and breaks the connection, and vice versa if the contacts were open. When the current to the coil is switched off, the armature is returned by a force, approximately half as strong as the magnetic force, to its relaxed position. Usually this force is provided by a spring, but gravity is also used commonly in industrial motor starters. Most relays are manufactured to operate quickly. In a low-voltage application this reduces noise.Applications:

Relays are used to realize logic functions. They play a very important role in providing safety critical logic. Relays are used to provide time delay functions. They are used to time the delay open and delay close of contacts. Relays are used to control high voltage circuits with the help of low voltage signals. Similarly they are used to control high current circuits with the help of low current signals. They are also used as protective relays. By this function all the faults during transmission and reception can be detected and isolated.

RESISTORS

The flow of charge through any material encounters an opposing force similar in many respects to mechanical friction .this opposing force is called resistance of the material .in some electric circuit resistance is deliberately introduced in form of resistor. Resistor used fall in three categories , only two of which are color coded which are metal film and carbon film resistor .the third category is the wire wound type ,where value are generally printed on the vitreous paint finish of the component. Resistors are in ohms and are represented in Greek letter omega, looks as an upturned horseshoe. Most electronic circuit require resistors to make them work properly and it is obliviously important to find out something about the different types of resistors available. Resistance is measured in ohms, the symbol for ohm is an omega ohm. 1 ohm is quite small for electronics so resistances are often given in kohm and Mohm.Resistors used in electronics can have resistances as low as 0.1 ohm or as high as 10 Mohm.

Figure 112 Symbol of Resistance

TESTING

Resistors are checked with an ohm meter/millimeter. For a defective resistor the ohm-meter shows infinite high reading.

CAPACITORS

In a way, a capacitor is a little like a battery. Although they work in completely different ways, capacitors and batteries both store electrical energy. If you have read How Batteries Work, then you know that a battery has two terminals. Inside the battery, chemical reactions produce electrons on one terminal and absorb electrons at the other terminal.

BASIC

Like a battery, a capacitor has two terminals. Inside the capacitor, the terminals connect to two metal plates separated by a dielectric. The dielectric can be air, paper, plastic or anything else that does not conduct electricity and keeps the plates from touching each other. You caneasily make a capacitor from two pieces of aluminum foil and a piece of paper. It won't be a particularly good capacitor in terms of its storage capacity, but it will work.

In an electronic circuit, a capacitor is shown like this:

Figure 113 Capacitor

When you connect a capacitor to a battery, heres what happens:

The plate on the capacitor that attaches to the negative terminal of the battery accepts electrons that the battery is producing.

The plate on the capacitor that attaches to the positive terminal of the battery loses electrons to the battery.

Figure 114 Capacitor & Battery Connection

TESTING

To test the capacitors, either analog meters or special digital meters with the specified function are used. The non-electrolyte capacitor can be tested by using the digital meter.

CRYSTAL OSCILLATORS

Crystal oscillators are oscillators where the primary frequency determining element is a quartz crystal. Because of the inherent characteristics of the quartz crystal the crystal oscillator may be held to extreme accuracy of frequency stability. Temperature compensation may be applied to crystal oscillators to improve thermal stability of the crystal oscillator. Crystal oscillators are usually, fixed frequency oscillators where stability and accuracy are the primary considerations. For example it is almost impossible to design a stable and accurate LC oscillator for the upper HF and higher frequencies without resorting to some sort of crystal control. Hence the reason for crystal oscillators. The frequency of older FT-243 crystals can be moved upward by crystal grinding.

Features: Frequency: 11.0592MHz Frequency Stability: 30ppm Frequency Tolerance: - Load Capacitance: 15pF Operating Temperature Max: 70C Operating Temperature Min: -20C Oscillator Mounting: SMD Supply Voltage Max: 3.63V Supply Voltage Min: 2.97V

DESIGN

1. BLOCK DIAGRAM

Figure 21 Block Diagram of Project Idea Circuit Diagram

Figure 22 Circuit diagram of project

Circuit Layout

Figure 23 Circuit Layout

Circuit Description Circuit for cellphonebased device control with voice acknowledgement. It comprises microcontroller ATMEGA8, DTMF decoder MT8870, voice recording/playback device and a few discrete components. Microcontroller AT89C51 is at the heart of the circuit. It is a low-power, high-performance, 8-bit microcontroller with 4 kB of flash programmable and erasable read-only memory (PEROM) used as on-chip program memory, 128 bytes of RAM used as internal data memory, 32 individually programmable input/output (I/O) lines divided into four 8-bit ports, two 16-bit programmable timers/counters, a five-vector two-level interrupt architecture, on-chip oscillator and clock circuitry. A 11.0592MHz crystal (XTAL1) is used to provide basic clock frequency for the microcontroller. Capacitor C3 and resistor R3 form the power-on reset circuit, while push-to-on switch S20 is used for manual reset. Port pins P1.0 through P1.7 of the microcontroller are configured to getthe input from push-to-on switches S1 through S8. Pins of Port P1 are pulled high via resistor network RNW1. Port pins P2.0 through P2.4 are configured to receive the decoded DTMF signal from DTMF receiver MT8870. The functions of the corresponding switches and cellphone keys.

WORKING OF PROJECT

The working of this project is controlled by a microcontroller ATMEGA8 and a DTMF decoder MT8870 is used for decoding key tones of cell phone and EEPROM is used for memory storage. The project works in the following ways:

1. Switch on power supply.

2. Message all devices off will appear on LCD.

3. Type any of the number present on the keypad of cellphone which is with user.

4. The status will appear on the LCD whether appliance is on or off.

5. To switch-off the appliance again click the same number on DTMF keypad.

6. A reset key is present to reset the microcontroller.

PCB Layout

Figure 24 PCB layout of project

PCB PREPARATION

(a) Photo-Resist Board is a piece of glass reinforces plastic. One of the sides is copper clad and this copper has a photosensitive coating. When the plastic film is peeled back this sensitive coating is revealed. After processing this will be the PCB.

Figure 25 First Stage

(b) The PCB mask (now on a transparency) is placed underneath the photo-resist board, touching the sensitive surface. Remember the plastic film must be removed. PCB mask and board are then transferred to the Ultra-Violet light box. You must be careful to ensure that the PCB mask is the right way up; otherwise when the circuit is etched you will discover that the tracks are also the wrong way round.

Figure 26 Second Stage

(c) The etchant is held in a bubble etch tank and is heated. This solution solely etches away the unwanted copper, leaving the tracks only. At this stage it is important to keep checking that the PCB is complete (time 15 to 45 minutes). If it is left in the tank too long the copper tracks will also be removed or damaged.

Figure 27 Third Stage

(d) When removed from the etching solution, the PCB is washed and a PCB eraser is used to remove any film from the tracks. This must be done carefully because the film will prevent good soldering of the components to the PCB. The tracks can be checked using a magnifying glass. If there are gaps in the tracks, sometimes they can be repaired using wire but usually a new PCB has to be etched.

Figure 28 Forth Stage

(e)The last stage is drilling the hole for component. A small PCB drill is used for this purpose. Again care is needed as a good PCB can be ruined by careless drilling.

Figure 29 Fifth Stage

(f) This complete Printed Circuit Board (PCB)has all its components soldered in position. It has been manufactured through the processes described in the information sheet. PCBs manufactured in industry are designed on a computer and then manufacturedon a production line controlled by computers. Usually there is very little human contact.

Figure 210 Sixth Stage

SOFTWARE

Source Code:

* Dtmf_Home_appliance.c * * Created: 27-04-2014 02:02:43 AM * Author: bestbuddyrohit */

#include #include #include "lcd.h"

unsigned char LUT[];char getkeypressed(){PORTC|=0xff;static char last=0;if (bit_is_set(PINC,0)){int temp=PINC&(0b0011110);if (temp!=last){char key=LUT[temp];last=temp;return key;}elsereturn 'A';}elsereturn 'A';}

unsigned char LUT[] ={0,0,'8',0,'4',0,'#',0,'2',0,'0',0,'6',0,0,0,'1',0,'9',0,'5',0,0,0,'3',0,'*',0,'7',0,0,0,0,};

/*

key 1: 16key 2: 8key 3: 24key 4: 4key 5: 20key 6: 12key 7: 28key 8 :2key 9: 18key * :26key 0 :10key #:6default : 0;

*/

int main(void){_delay_ms(1000);LCDInit(LS_NONE);LCDClear();DDRB|=(1