PROJECT REPORT ON ELECTION VOTING VIA SMS

Transcription

1 PROJECT REPORT ON ELECTION VOTING VIA SMS BY ROHAN.S.GAVANKAR ( ) RONAK.P.KAMDAR ( ) SHASHANK.S.KATKAR ( ) UNDER THE GUIDANCE OF Prof. SHARVARI. P.DESHMANE IN PARTIAL FULFILLMENT OF B.E. ELECTRONICS & TELECOMMUNICATION DEGREE OF UNIVERSITY OF MUMBAI DEPARTMENT OF ELECTRONICS & TELECOMMUNICATION K.J.SOMAIYA COLLEGE OF ENGINERING, VIDYAVIHAR, MUMBAI ( )

2 K.J.SOMAIYA COLLEGE OF ENGINEERING, VIDYAVIHAR, MUMBAI DEPARTMENT OF ELECTRONICS &TELECOMMUNICATION CERTIFICATE This is to certify that the following students Rohan.S. Gavankar (EXTC B-85) Ronak.P. Kamdar (EXTC B-87) Shashank. S. Katkar (EXTC B-94) have successfully completed the project Titled ELECTION VOTING VIA SMS towards the partial fulfillment of degree of Bachelor of Engineering in Electronics and Telecommunications of the University of Mumbai during academic year Name & Designation Name & Designation Internal Guide External Guide Prof.(Mrs.) J.M.Kundargi Head of the Department Dr. (Mrs.) Medha Dixit Principal INTERNAL EXAMINER EXTERNAL EXAMINER

3 ABSTRACT Using SMS Based Voting machine we can vote from our home just by sending a sms a specified format from our mobile. The entire voters will be provided with a unique password (pin) and identification number. For voting we have to send a sms in a predefined format. The voting machine will receive this messages and decode the message and verify the the Pin number and identification number if both number matches the voting machine will accept the vote else the message is rejected by the machine. The voting machine is implemented using P89V51RD2 microcontroller.a GSM MODEM is used to receive messages from voters. The microcontroller accepts this message and verifies the message and keep updates. An LCD is used to display the result.

4 ACKNOWLEDGMENT We wish to express my sincere gratitude to Prof. J. M. Kundargi, (Head of EXTC Department) for providing us an opportunity to do our project work on ELECTION VOTING VIA SMS. This project bears on imprint of many people. We sincerely thank our project guide Prof. Sharvari.P.Deshmane for channelizing us towards the successful completion of our project. We also wish to express our gratitude to the officials and other staff members of KJSCE who rendered their help during the period of our project work. Our special thanks to Prof. Mrunal.P.Chandane for her vital insights and kind co-operation to the completion of our project work. Last but not the least, we thank our family for giving us life in first place, for educating us with aspects from both arts and sciences, for unconditional support and encouragement to pursue our interests, even when the interests went beyond boundaries of language, field and geography. 1

5 TABLE OF CONTENTS: Sr. No. Page Title Page No. 1 Title page i 2 Certificate ii 3 Abstract iii 4 Acknowledgment iv 5 Introduction 4 6 Chapter 1:Introduction to P89V51RD2 Microcontroller 1.1 General Description Features Block diagram Pin diagram Pin description Memory organization Flash Memory in Application Programming 13 7 Chapter 2:Max 232 IC Explanation 15 8 Chapter 3:GSM Module Features AT Commands 18 2

6 Sr. no Page Title Pg.no General Syntax of Extended AT Commands Result code of AT commands SMS tutorial 28 9 Chapter 4: Hitachi LCD display Features Chapter 5: Block diagram Block diagram explanation Circuit diagram Circuit diagram explanation Flowchart Hardware used Software used References 61 3.

7 LIST OF TABLES & FIGURES Sr. No. Title Page No. 1.1 P89V51RB2/RC2/RD2 BLOCK DIAGRAM P89V51RD2 Pin diagram P89V51RD2 pin description P89V51RD2 pin description P89V51RD2 pin description Internal and External data memory structure of P89V51RD Max 232 IC SIM 300 GSM Module The screenshot of MS HyperTerminal's Connection Description dialog box in Win The screenshot of MS HyperTerminal's Connect To dialog box in Windows The screenshot of MS HyperTerminal's Properties dialog box in Windows The screenshot of MS HyperTerminal's main window in Windows Hitachi LCD display Block Diagram Circuit diagram voltage regulator Bridge Rectifier Flowchart CXX test board kit 58 4

8 1.INTRODUCTION India is world s largest democracy. Fundamental right to vote or simply voting in elections forms the basis of Indian democracy. In India all earlier elections a voter used to cast his vote by using ballot paper. This is a longtime-consuming process and very much prone to errors. This situation continued till election scene was completely changed by electronic voting machine. No more ballot paper, ballot boxes, stamping,etc.all this condensed into a simple box called ballot unit of the electronic voting machine. Cell phone based voting machine is capable of saving considerable printing stationery and transport of large volumes of electoral material. It is easy to transport, store, and maintain. It completely rules out the chance of invalid votes. Its use results reduction of polling time, resulting in fewer problems in electoral preparations, law and order, candidates' expenditure,etc. and easy and accurate counting without any mischief at the counting centre. The aim of our project is to design & develop a mobile based voting machine. This Project focuses onto implement GSM (Global System for Mobile Communication) based Voting System. This system is implemented using an embedded microcontroller. The embedded microcontroller used here is P89V51RD2. Actually, the aim of the project is to implement an Automatic Voting system. GSM Based voting machine is fully controlled system. There is no chance of any mistake. Primarily, the system functions with the help of different technologies like the traditional cellular network such as Global System for Mobile Communications (GSM) and other radio frequency medium. Today GSM fitted Banks, cars; ambulances, fleets and police vehicles are common sights. The functional units of our projects are GSM MODEM, LCD display, P89V51RD2. 5

9 CHAPTER 1: INTRODUCTION TO P89V51RD2 MICROCONTROLLER 1. 1 General description The P89V51RB2/RC2/RD2 are 80C51 microcontrollers with 16/32/64 kb Flash and 1024 bytes of data RAM. A key feature of the P89V51RB2/RC2/RD2 is its X2 mode option. The design engineer can choose to run the application with the conventional 80C51 clock rate (12 clocks per machine cycle) or select the X2 mode (6 clocks per machine cycle) to achieve twice the throughput at the same clock frequency. Another way to benefit from this feature is to keep the same performance by reducing the clock frequency by half, thus dramatically reducing the EMI. The Flash program memory supports both parallel programming and in serial In-System Programming (ISP). Parallel programming mode offers gang-programming at high speed, reducing programming costs and time to market. ISP allows a device to be reprogrammed in the end product under software control. The capability to field/update the application firmware makes a wide range of applications possible. The P89V51RB2/RC2/RD2 is also In-Application Programmable (IAP), allowing the Flash program memory to be reconfigured even while the application is running. 6

10 1.2. Features 1. 80C51 Central Processing Unit 2. 5 V Operating voltage from 0 MHz to 40 MHz 3. 16/32/64 kb of on-chip Flash user code memory with ISP (In-System Programming) and IAP (In-Application Programming) 4. Supports 12-clock (default) or 6-clock mode selection via software or ISP SPI (Serial Peripheral Interface) and enhanced UART 5. PCA (Programmable Counter Array) with PWM and Capture/Compare functions 6. Four 8-bit I/O ports with three high-current Port 1 pins (16 ma each) 7. Three 16-bit timers/counters 8. Programmable watchdog timer 9. Eight interrupt sources with four priority levels 10. Second DPTR register 11. Low EMI mode (ALE inhibit) 12. TTL- and CMOS-compatible logic levels 13. DIP40, PLCC44 and TQFP44 packages 7

11 1.3 Block Diagram Figure 1.1 8

12 1.4. Pin diagram Figure 1.2 9

13 1.5 Pin Description Figure

14 Figure

15 Figure

16 1.6 Memory Organization Figure

17 1.7 Flash Memory in Application programming Flash Organization The P89V51RB2/RC2/RD2 program memory consists of a 16/32/64 kb block. An In- System Programming (ISP) capability, in a second 8 kb block, is provided to allow the user code to be programmed in-circuit through the serial port. There are three methods of erasing or programming of the Flash memory that may be used. First, the Flash may be programmed or erased in the end-user application by calling low-level routines through a common entry point (IAP). Second, the on-chip ISP boot loader may be invoked. This ISP boot loader will, in turn, call low-level routines through the same common entry point that can be used by the end-user application. Third, the Flash may be programmed or erased using the parallel method by using a commercially available EPROM programmer which supports this device Boot Block When the microcontroller programs its own Flash memory, all of the low level details are handled by code that is contained in Block 1. A user program calls the common entry point in the Block 1 with appropriate parameters to accomplish the desired operation. Boot block operations include erase user code, program user code, program security bits, etc. A Chip-Erase operation can be performed using a commercially available parallel programer. This operation will erase the contents of this Boot Block and it will be necessary for the user to reprogram this Boot Block (Block 1) with the Philips-provided ISP/IAP code in order to use the ISP or IAP capabilities of this device In-System Programming In-System Programming is performed without removing the microcontroller from the System. The In-System Programming facility consists of a series of internal hardware resources coupled with internal firmware to facilitate remote programming of the P89V51RB2/RC2/RD2 through the serial port. This firmware is provided by Philips and embedded within each P89V51RB2/RC2/RD2 device. The Philips In-System Programming facility has made in-circuit programming in an embedded application The ISP function uses five pins (VDD, VSS, TxD, RxD, and RST). Only a small Connector needs to be available to interface your application to an external circuit in Order to use this feature. 14

18 CHAPTER 2: MAX 232 IC Figure

19 2.1 Features The MAX232 is an integrated circuit that converts signals from an RS-232 serial port to signals suitable for use in TTL compatible digital logic circuits. The MAX232 is a dual driver/receiver and typically converts the RX, TX, CTS and RTS signals. The drivers provide RS- 232 voltage level outputs (approx. ± 7.5 V) from a single +5V supply via on-chip charge pumps and external capacitors. This makes it useful for implementing RS-232 in devices that otherwise do not need any voltages outside the 0 V to + 5 V range, as power supply design does not need to be made more complicated just for driving the RS-232 in this case. The receivers reduce RS-232inputs (which may be as high as ± 25 V), to standard 5 V TTL levels. These receivers have atypical threshold of 1.3 V, and a typical hysteresis of 0.5 V. The later MAX232A is backwards compatible with the original MAX232 but may operate at higher baud rates and can use smaller external capacitors ± 0.1 F in place of the 1.0 F capacitors used with the original device. The newer MAX3232 is also backwards compatible, but operates at a broader voltage range, from 3 to 5.5V. 16

20 CHAPTER 3: GSM MODULE Figure

21 3.1 Features A GSM modem is a wireless modem that works with a GSM wireless network. A wireless modem behaves like a dial-up modem. The main difference between them is that a dial- up modem sends and receives data through a fixed telephone line while a wireless modem Sends and receives data through radio waves. A GSM modem can be an external device or a PC Card PCMCIA Card. Typically, an external GSM modem is connected to a computer through a serial cable or a USB cable. A GSM modem in the form of a PC Card / PCMCIA Card is designed for use with a laptop computer. It should be inserted into one of the PC Card /PCMCIA Card slots of a laptop computer. Like a GSM mobile phone, a GSM modem requires a SIM card from a wireless carrier in order to operate. As mentioned below of this SMS tutorial l computers use AT commands to control modems. Both GSM modems and dial-up modems support a common set of standard AT commands. You can use a GSM modem just like a dialup modem. In addition to the standard AT commands; GSM modems support an extended set of AT commands. These extended AT commands are defined in the GSM standards. With the extended AT commands, you can do things like: 1. Reading, writing and deleting SMS messages. 2. Sending SMS messages. 3. Monitoring the signal strength. 4. Monitoring the charging status and charge level of the battery. 5. Reading, writing and searching phone book entries. The number of SMS messages that can be processed by a GSM modem per minute is very low -- only about six to ten SMS messages per minute. 18

22 3.2 AT Commands AT commands are instructions used to control a modem. AT is the abbreviation of ATtention. Every command line starts with "AT" or "at". That's why modem commands are called AT commands. Many of the commands that are used to control wired dial-up modems, such as ATD (Dial), ATA (Answer), ATH (Hook control) and ATO (Return to online data state), are also supported by GSM/GPRS modems and mobile phones. Besides this common AT command set, GSM/GPRS modems and mobile phones support an AT command set that is specific to the GSM technology, which includes SMS-related commands like AT+CMGS (Send SMS message), AT+CMSS (Send SMS message from storage), AT+CMGL (List SMS messages) and AT+CMGR (Read SMS messages). Note that the starting "AT" is the prefix that informs the modem about the start of a command line. It is not part of the AT command name. For example, D is the actual AT command name in ATD and +CMGS is the actual AT command name in AT+CMGS. However, some books and web sites use them interchangeably as the name of an AT command. Here are some of the tasks that can be done using AT commands with a GSM/GPRS modem or mobile phone: Get basic information about the mobile phone or GSM/GPRS modem. For example, name of manufacturer (AT+CGMI), model number (AT+CGMM), IMEI number (International Mobile Equipment Identity) (AT+CGSN) and software version (AT+CGMR). Get basic information about the subscriber. For example, MSISDN (AT+CNUM) and IMSI number (International Mobile Subscriber Identity) (AT+CIMI). Get the current status of the mobile phone or GSM/GPRS modem. For example, mobile phone activity status (AT+CPAS), mobile network registration status (AT+CREG), radio signal strength (AT+CSQ), battery charge level and battery charging status (AT+CBC). 19

23 Establish a data connection or voice connection to a remote modem (ATD, ATA, etc). Send and receive fax (ATD, ATA, AT+F*). Send (AT+CMGS, AT+CMSS), read (AT+CMGR, AT+CMGL), write (AT+CMGW) or delete (AT+CMGD) SMS messages and obtain notifications of newly received SMS messages (AT+CNMI). Read (AT+CPBR), write (AT+CPBW) or search (AT+CPBF) phonebook entries. Perform security-related tasks, such as opening or closing facility locks (AT+CLCK), checking whether a facility is locked (AT+CLCK) and changing passwords (AT+CPWD). (Facility lock examples: SIM lock [a password must be given to the SIM card every time the mobile phone is switched on] and PH-SIM lock [a certain SIM card is associated with the mobile phone. To use other SIM cards with the mobile phone, a password must be entered.]) Control the presentation of result codes / error messages of AT commands. For example, you can control whether to enable certain error messages (AT+CMEE) and whether error messages should be displayed in numeric format or verbose format (AT+CMEE=1 or AT+CMEE=2). Get or change the configurations of the mobile phone or GSM/GPRS modem. For example, change the GSM network (AT+COPS), bearer service type (AT+CBST), radio link protocol parameters (AT+CRLP), SMS center address (AT+CSCA) and storage of SMS messages (AT+CPMS). Save and restore configurations of the mobile phone or GSM/GPRS modem. For example, save (AT+CSAS) and restore (AT+CRES) settings related to SMS messaging such as the SMS center address. 20

24 Note that mobile phone manufacturers usually do not implement all AT commands, command parameters and parameter values in their mobile phones. Also, the behavior of the implemented AT commands may be different from that defined in the standard. In general, GSM/GPRS modems designed for wireless applications have better support of AT commands than ordinary mobile phones. In addition, some AT commands require the support of mobile network operators. For example, SMS over GPRS can be enabled on some GPRS mobile phones and GPRS modems with the +CGSMS command (command name in text: Select Service for MO SMS Messages). But if the mobile network operator does not support the transmission of SMS over GPRS, you cannot use this features.there are two types of AT commands: basic commands and extended commands. Basic commands are AT commands that do not start with "+". For example, D (Dial), A (Answer), H (Hook control) and O (Return to online data state) are basic commands. Extended commands are AT commands that start with "+". All GSM AT commands are extended commands. For example, +CMGS (Send SMS message), +CMSS (Send SMS message from storage), +CMGL (List SMS messages) and +CMGR (Read SMS messages) are extended commands. [4] 21

25 3.3 General Syntax of Extended AT Commands The general syntax of extended AT commands is straightforward. The syntax rules are provided below. The syntax of basic AT commands is slightly different. We will not cover the syntax of basic AT commands in this SMS tutorial since all SMS messaging commands are extended AT commands. Syntax rule 1. All command lines must start with "AT" and end with a carriage return character. (We will use <CR> to represent a carriage return character in this SMS tutorial.) In a terminal program like HyperTerminal of Microsoft Windows, you can press the Enter key on the keyboard to output a carriage return character. Example: To list all unread inbound SMS messages stored in the message storage area, type "AT", then the extended AT command "+CMGL", and finally a carriage return character, like this: AT+CMGL<CR> Syntax rule 2. A command line can contain more than one AT command. Only the first AT command should be prefixed with "AT". AT commands in the same command-line string should be separated with semicolons. Example: To list all unread inbound SMS messages stored in the message storage area and obtain the manufacturer name of the mobile device, type "AT", then the extended AT command "+CMGL", followed by a semicolon and the next extended AT command "+CGMI": 22

26 AT+CMGL;+CGMI<CR> An error will occur if both AT commands are prefixed with "AT", like this: AT+CMGL;AT+CGMI<CR> Syntax rule 3. A string is enclosed between double quotes. Example: To read all SMS messages from message storage in SMS text mode (at this time you do not need to know what SMS text mode is. More information will be provided later in this SMS tutorial), you need to assign the string "ALL" to the extended AT command +CMGL, like this: AT+CMGL="ALL"<CR> Syntax rule 4. Information responses and result codes (including both final result codes and unsolicited result codes) always start and end with a carriage return character and a linefeed character. Example: After sending the command line "AT+CGMI<CR>" to the mobile device, the mobile device should return a response similar to this: <CR><LF>Nokia<CR><LF> <CR><LF>OK<CR><LF> 23

27 The first line is the information response of the AT command +CGMI and the second line is the final result code. <CR> and <LF> represent a carriage return character and a linefeed character respectively. The final result code "OK" marks the end of the response. It indicates no more data will be sent from the mobile device to the computer / PC. When a terminal program such as HyperTerminal of Microsoft Windows sees a carriage return character, it moves the cursor to the beginning of the current line. When it sees a linefeed character, it moves the cursor to the same position on the next line. Hence, the command line "AT+CGMI<CR>" that you entered and the corresponding response will be displayed like this in a terminal program such as HyperTerminal of Microsoft Windows: AT+CGMI Nokia OK Information Response and Final Result Code Don't forget the meanings of information response and final result code stated above, since you will see these two terms frequently as you go through this SMS tutorial. AT+CGMI <-- Command line entered Nokia <-- Information response OK <-- Final result code [4] 24

28 3.4 Result codes of AT commands Result codes are messages sent from the GSM/GPRS modem or mobile phone to provide you information about the execution of an AT command and the occurrence of an event. Two types of result codes are useful to you when dealing with AT commands for SMS messaging: Final result codes Unsolicited result codes Final Result Codes of AT Commands A final result code marks the end of an AT command response. It is an indication that the GSM/GPRS modem or mobile phone has finished the execution of a command line. Two frequently used final result codes are OK and ERROR. Only one final result code will be returned for each command line. Thus, you will not see both OK and ERROR in the response of a command line The OK Final Result Code The OK final result code indicates that a command line has been executed successfully by the GSM/GPRS modem or mobile phone. It always starts and ends with a carriage return character and a linefeed character. Here is an example for illustration. Let's say you send the command line "AT+CMGL;+CGMI<CR>" to your GSM/GPRS modem. The AT command "+CMGL" is used to list SMS messages stored in the message storage area and the AT command "+CGMI" is used to get the manufacturer name of the GSM/GPRS modem. If everything works properly without any errors, the command line, together with the response returned, should be something similar to this: 25

29 AT+CMGL;+CGMI<CR> <CR><LF>+CMGL: 1,"REC UNREAD"," ",,"06/11/11,00:30:29+32"<CR><LF> Welcome to our SMS tutorial.<cr><lf> <CR><LF>Nokia<CR><LF> <CR><LF>OK<CR><LF> As mentioned earlier, when a terminal program such as HyperTerminal of Microsoft Windows sees a carriage return character, it moves the cursor to the beginning of the current line. When it sees a linefeed character, it moves the cursor to the same position on the next line. Hence, the command line you entered, together with the response returned, will be displayed like this in a terminal program such as HyperTerminal of Microsoft Windows: AT+CMGL;+CGMI +CMGL: 1,"REC UNREAD"," ",,"06/11/11,00:30:29+32" Welcome to our SMS tutorial. Nokia OK The ERROR Final Result Code The ERROR final result code indicates that an error occurs when the GSM/GPRS modem or mobile phone tries to execute a command line. After the occurrence of an 26

30 error, the GSM/GPRS modem or mobile phone will not process the remaining AT commands in the command-line string. Below are some common causes of error: The syntax of the command line is incorrect. The value specified to a certain parameter is invalid. The name of the AT command is spelt incorrectly. The GSM/GPRS modem or mobile phone does not support one or more of the AT commands, command parameters or parameter values in the commandline string. Like the OK final result code, the ERROR final result code always starts and ends with a carriage return character and a linefeed character. Here is an example for illustration. Suppose you want to instruct your GSM/GPRS modem to list SMS messages from the message storage area and get the manufacturer name of the GSM/GPRS modem. You intend to type the command line "AT+CMGL;+CGMI<CR>" but make a careless mistake by typing "+CMFL" instead of "+CMGL". The GSM/GPRS modem will return the ERROR final result code, as shown below: AT+CMFL;+CGMI<CR> <CR><LF>ERROR<CR><LF> As an error occurs when the GSM/GPRS modem processes "+CMFL", the GSM/GPRS modem stops the execution of the command line and so the second AT command "+CGMI" is not processed. 27

31 If you type the second AT command "+CGMI" incorrectly instead of the first AT command "+CMGL", the GSM/GPRS modem will output the result of the execution of the AT command "+CMGL" before outputting the ERROR final result code, like this: AT+CMGL;+CGMU<CR> <CR><LF>+CMGL: 1,"REC UNREAD"," ",,"06/11/11,00:30:29+32"<CR><LF> Welcome to our SMS tutorial.<cr><lf> <CR><LF>ERROR<CR><LF> As mentioned earlier, when a terminal program such as HyperTerminal of Microsoft Windows sees a carriage return character, it moves the cursor to the beginning of the current line. When it sees a linefeed character, it moves the cursor to the same position on the next line. Hence, the command line you entered, together with the response returned, will be displayed like this in a terminal program such as HyperTerminal of Microsoft Windows: AT+CMGL;+CGMU +CMGL: 1,"REC UNREAD"," ",,"06/11/11,00:30:29+32" Welcome to our SMS tutorial. ERROR [4] 28

32 3.5 SMS tutorial In general, there are two ways to send SMS messages from a computer / PC to a mobile phone: 1. Connect a mobile phone or GSM/GPRS modem to a computer / PC. Then use the computer / PC and AT commands to instruct the mobile phone or GSM/GPRS modem to send SMS messages. 2. Connect the computer / PC to the SMS center (SMSC) or SMS gateway of a wireless carrier or SMS service provider. Then send SMS messages using a protocol / interface supported by the SMSC or SMS gateway The 1st Way: Sending SMS Messages from a Computer Using a Mobile Phone or GSM/GPRS Modem The SMS specification has defined a way for a computer to send SMS messages through a mobile phone or GSM/GPRS modem. A GSM/GPRS modem is a wireless modem that works with GSM/GPRS wireless networks. A wireless modem is similar to a dial-up modem. The main difference is that a wireless modem transmits data through a wireless network whereas a dial-up modem transmits data through a copper telephone line. Most mobile phones can be used as a wireless modem. However, some mobile phones have certain limitations comparing to GSM/GPRS modems. To send SMS messages, first place a valid SIM card from a wireless carrier into a mobile phone or GSM/GPRS modem, which is then connected to a computer. There are several ways to connect a mobile phone or GSM/GPRS modem to a computer. For example, they can be connected through a serial cable, a USB cable, a Bluetooth link or an infrared link. The actual way to use depends on the capability of the mobile phone or GSM/GPRS modem. For example, if a mobile phone does not support Bluetooth, it cannot connect to the computer through a Bluetooth link. 29

33 After connecting a mobile phone or GSM/GPRS modem to a computer, you can control the mobile phone or GSM/GPRS modem by sending instructions to it. The instructions used for controlling the mobile phone or GSM/GPRS modem are called AT commands. (AT commands are also used to control dial-up modems for wired telephone system.) Dial-up modems, mobile phones and GSM/GPRS modems support a common set of standard AT commands. In addition to this common set of standard AT commands, mobile phones and GSM/GPRS modems support an extended set of AT commands. One use of the extended AT commands is to control the sending and receiving of SMS messages. The following table lists the AT commands that are related to the writing and sending of SMS messages: AT command Meaning +CMGS Send message +CMSS Send message from storage +CMGW Write message to memory +CMGD Delete message +CMGC Send command +CMMS More messages to send One way to send AT commands to a mobile phone or GSM/GPRS modem is to use a terminal program. A terminal program's function is like this: It sends the characters you typed to the mobile phone or GSM/GPRS modem. It then displays the response it 30

34 receives from the mobile phone or GSM/GPRS modem on the screen. The terminal program on Microsoft Windows is called HyperTerminal. Below shows a simple example that demonstrates how to use AT commands and the HyperTerminal program of Microsoft Windows to send an SMS text message. The lines in bold type are the command lines that should be entered in HyperTerminal. The other lines are responses returned from the GSM / GPRS modem or mobile phone. AT OK AT+CMGF=1 OK AT+CMGW=" " > A simple demo of SMS text messaging. +CMGW: 1 OK AT+CMSS=1 +CMSS: 20 OK 31

35 Here is a description of what is done in the above example: Line 1: "AT" is sent to the GSM / GPRS modem to test the connection. The GSM / GPRS modem sends back the result code "OK" (line 2), which means the connection between the HyperTerminal program and the GSM / GPRS modem works fine. Line 3: The AT command +CMGF is used to instruct the GSM / GPRS modem to operate in SMS text mode. The result code "OK" is returned (line 4), which indicates the command line "AT+CMGF=1" has been executed successfully. If the result code "ERROR" is returned, it is likely that the GSM / GPRS modem does not support the SMS text mode. To confirm, type "AT+CMGF=?" in the HyperTerminal program. If the response is "+CMGF: (0,1)" (0=PDU mode and 1=text mode), then SMS text mode is supported. If the response is "+CMGF: (0)", then SMS text mode is not supported. Line 5 and 6: The AT command +CMGW is used to write an SMS text message to the message storage of the GSM / GPRS modem. " " is the recipient mobile phone number. After typing the recipient mobile phone number, you should press the Enter button of the keyboard. The GSM / GPRS modem will then return a prompt "> " and you can start typing the SMS text message "A simple demo of SMS text messaging.". When finished, press Ctrl+z of the keyboard. Line 7: "+CMGW: 1" tells us that the index assigned to the SMS text message is 1. It indicates the location of the SMS text message in the message storage. Line 9: The result code "OK" indicates the execution of the AT command +CMGW is successful. Line 10: The AT command +CMSS is used to send the SMS text message from the message storage of the GSM / GPRS modem. "1" is the index of the SMS text message obtained from line 7. Line 11: "+CMSS: 20" tells us that the reference number assigned to the SMS text message is

36 Line 13: The result code "OK" indicates the execution of the AT command +CMSS is successful. To send SMS messages from an application, you have to write the source code for connecting to and sending AT commands to the mobile phone or GSM/GPRS modem, just like what a terminal program does. You can write the source code in C, C++, Java, Visual Basic, Delphi or other programming languages you like. However, writing your own code has a few disadvantages: You have to learn how to use AT commands. You have to learn how to compose the bits and bytes of an SMS message. For example, to specify the character encoding (e.g. 7-bit encoding and 16-bit Unicode encoding) of an SMS message, you need to know which bits in the message header should be modified and what value should be assigned. Sending SMS messages with a mobile phone or GSM/GPRS modem has a drawback -- the SMS transmission speed is low. As your SMS messaging application becomes more popular, it has to handle a larger amount of SMS traffic and finally the mobile phone or GSM/GPRS modem will not be able to take the load. To obtain a high SMS transmission speed, a direct connection to an SMSC or SMS gateway of a wireless carrier or SMS service provider is needed. However, AT commands are not used for communicating with an SMS center or SMS gateway. This means your have to make a big change to your SMS messaging application in order to move from a wireless- modembased solution to a SMSC-based solution. In most cases, instead of writing your own code for interacting with the mobile phone or GSM/GPRS modem via AT commands, a better solution is to use a high-level SMS messaging API (Application programming interface) / SDK (Software development kit) / library. The API / SDK / library encapsulates the low-level details. So, an SMS application developer does not need to know AT commands and the composition of SMS messages in the bit-level. Some SMS messaging APIs / SDKs / libraries support SMSC protocols in addition to AT commands. To move from a wireless-modem-based SMS solution to a SMSC-based SMS solution, usually you 33

37 just need to modify a configuration file / property file or make a few changes to your SMS messaging application's source code. Another way to hide the low-level AT command layer is to place an SMS gateway between the SMS messaging application and the mobile phone or GSM/GPRS modem. (This has been described in the section "What is an SMS Gateway?" earlier.) Simple protocols such as HTTP / HTTPS can then be used for sending SMS messages in the application. If an SMSC protocol (e.g. SMPP, CIMD, etc) is used for communicating with the SMS gateway instead of HTTP / HTTPS, an SMS messaging API / SDK / library can be very helpful to you since it encapsulates the SMSC protocol's details. Usually a list of supported / unsupported mobile phones or wireless modems is provided on the web site of an SMS messaging API / SDK / library or an SMS gateway software package. Remember to check the list if you are going to use an SMS messaging API / SDK / library or an SMS gateway software package Major Drawback of Sending SMS Messages through a Mobile Phone or GSM/GPRS Modem -- Low SMS Sending Rate Using a mobile phone or GSM/GPRS modem to send SMS messages has a major drawback, that is the SMS sending rate is too low. Only 6-10 SMS messages can be sent per minute (when the "SMS over GSM" mode is used). The performance is not affected by the connection between the computer and the mobile phone or GSM/GPRS modem (i.e. the SMS sending rate is about the same no matter the mobile phone or GSM/GPRS modem is connected to the computer through a serial cable, USB cable, Bluetooth link or infrared link) and does not depend on whether a mobile phone or GSM/GPRS modem is used (i.e. the SMS sending rate is about the same no matter a mobile phone or a GSM/GPRS modem is used). The determining factor for the SMS sending rate is the wireless network. 34

38 3.5.3 How to receive SMS messages using Computer/PC? In general, there are three ways to receive SMS messages using your computer / PC: 1. Connect a mobile phone or GSM/GPRS modem to a computer / PC. Then use the computer / PC and AT commands to get the received SMS messages from the mobile phone or GSM/GPRS modem. 2. Get access to the SMS center (SMSC) or SMS gateway of a wireless carrier. Any SMS messages received will be forwarded to your computer / PC using a protocol / interface supported by the SMSC or SMS gateway. 3. Get access to the SMS gateway of an SMS service provider. Any SMS messages received will be forwarded to your computer / PC using a protocol / interface supported by the SMS gateway The 1st Way: Using a Computer to Receive SMS Messages through a Mobile Phone or GSM/GPRS Modem Receiving SMS messages through a mobile phone or GSM/GPRS modem has a major advantage over the other two ways -- wireless carriers usually do not charge any fees for receiving incoming SMS messages with their SIM cards. The disadvantage of receiving SMS messages this way is that a mobile phone or GSM/GPRS modem cannot handle a large amount of SMS traffic. One way to overcome this is to load balance the SMS traffic with a pool of mobile phones or GSM/GPRS modems. Each mobile phone or GSM/GPRS modem will have its own SIM card and mobile phone number. In terms of programming, sending and receiving SMS messages through a mobile phone or GSM/GPRS modem are similar. What you need to do is to send instructions (in the form of AT commands) to the mobile phone or GSM/GPRS modem. The following table lists the AT commands that are related to the receiving and reading of SMS messages: 35

39 AT command Meaning +CNMI New message indications +CMGL List messages +CMGR Read messages +CNMA New message acknowledgement Below shows a simple example that demonstrates how to use AT commands and the HyperTerminal program of Microsoft Windows to read SMS text messages received by a GSM / GPRS modem or mobile phone. The lines in bold type are the command lines that should be entered in HyperTerminal. The other lines are responses returned from the GSM / GPRS modem or mobile phone. AT OK AT+CMGF=1 OK AT+CMGL="ALL" +CMGL: 1,"REC READ"," ",,"06/11/11,00:30:29+32" Hello, welcome to our SMS tutorial. +CMGL: 2,"REC READ"," ",,"06/11/11,00:32:20+32" A simple demo of SMS text messaging. OK 36

40 Here is a description of what is done in the above example: Line 1: "AT" is sent to the GSM / GPRS modem to test the connection. The GSM / GPRS modem sends back the result code "OK" (line 2), which means the connection between the HyperTerminal program and the GSM / GPRS modem works fine. Line 3: The AT command +CMGF is used to instruct the GSM / GPRS modem to operate in SMS text mode. The result code "OK" is returned (line 4), which indicates the command line "AT+CMGF=1" has been executed successfully. If the result code "ERROR" is returned, it is likely that the GSM / GPRS modem does not support the SMS text mode. To confirm, type "AT+CMGF=?" in the HyperTerminal program. If the response is "+CMGF: (0,1)" (0=PDU mode and 1=text mode), then SMS text mode is supported. If the response is "+CMGF: (0)", then SMS text mode is not supported. Line 5-9: The AT command +CMGL is used to list all SMS text messages in the message storage of the GSM / GPRS modem. There are two SMS text messages in the message storage: "Hello, welcome to our SMS tutorial." and "A simple demo of SMS text messaging.". " " is the sender mobile phone number. "06/11/11,00:30:29+32" and "06/11/11,00:32:20+32" tell us when the SMS text messages were received by the SMSC. "+32" is the time zone. Note that the unit is a quarter of an hour. So, +32 means GMT+8 hours, since 32 quarters of an hour = 8 hours. "REC READ" indicates both of the SMS text messages have been read before. Line 11: The result code "OK" indicates the execution of the AT command +CMGL is successful. To enable an application to receive SMS messages, you have to write the source code for connecting to and sending AT commands to the mobile phone or GSM/GPRS modem, just like what a terminal program (such as HyperTerminal of Microsoft 37

41 Windows) does. You can write the source code in C, C++, Java, Visual Basic, Delphi or other programming languages you like. However, like what we have discussed in the earlier section "The 1st Way: Sending SMS Messages from a Computer Using a Mobile Phone or GSM/GPRS Modem", usually a better solution is to use a high-level SMS messaging API (Application programming interface) / SDK (Software development kit) / library instead of writing your own code for interacting with the mobile phone or GSM/GPRS modem via AT commands. The API / SDK / library encapsulate the low-level details. So, an SMS application developer does not need to know AT commands and the composition of SMS messages in the bit-level. Some SMS messaging APIs / SDKs / libraries support SMSC protocols in addition to AT commands. To move from a wireless- modembased SMS solution to a SMSC-based SMS solution, usually you just need to modify a configuration file / property file or make a few changes to your SMS messaging application's source code. Another high-level solution is to place an SMS gateway between the SMS messaging application and the mobile phone or GSM/GPRS modem. The SMS messaging application can then use simple protocols such as HTTP / HTTPS for receiving SMS messages. If an SMSC protocol (e.g. SMPP, CIMD, etc) is used for communicating with the SMS gateway instead of HTTP / HTTPS, an SMS messaging API / SDK / library can be very helpful to you since it encapsulates the SMSC protocol's details. 38

42 How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem? Microsoft HyperTerminal is a small program that comes with Microsoft Windows. You can use it to send AT commands to your mobile phone or GSM/GPRS modem. It can be found at Start -> Programs ->Accessories -> Communications - > HyperTerminal. If you cannot find it and you are using Windows 98, then probably you have not installed it. You can go to Control Panel -> Add/Remove Programs - >Windows Setup tab -> Communications list box item -> Details button to install MS HyperTerminal. Before you start programming your SMS application, you may want to check if your mobile phone, GSM/GPRS modem and SIM card are working properly first. The MS HyperTerminal is a handy tool when it comes to testing your GSM devices. It is a good idea to test your GSM devices beforehand. When a problem occurs, sometimes it is difficult to tell what causes the problem. The cause can be your program, the GSM device or the SIM card. If you test your GSM device and SIM card with MS HyperTerminal and they operate properly, then it is very likely that the problem is caused by your program. For Linux users, minicom can be used instead of HyperTerminal. 39

43 The Procedure for Sending AT Commands to a Mobile Phone or GSM/GPRS Modem Using MS HyperTerminal To use MS HyperTerminal to send AT commands to your mobile phone or GSM/GPRS modem, you can follow the procedure below: 1. Put a valid SIM card into the mobile phone or GSM/GPRS modem. You can obtain a SIM card by subscribing to the GSM service of a wireless network operator. 2. Connect your mobile phone or GSM/GPRS modem to a computer and set up the corresponding wireless modem driver. You should find the wireless modem driver in the CD or disk that was provided by the manufacturer. If the manufacturer does not provide such CD or disk with your mobile pho ne or GSM/GPRS modem, you can go to the manufacturer's web site and see whether the wireless modem driver can be downloaded there. If the wireless modem driver cannot be found on the web site, you can still use Windows' standard modem driver. 3. Run MS HyperTerminal by selecting Start -> Programs -> Accessories - > Communications ->HyperTerminal. 4. In the Connection Description dialog box, enter a name and choose an icon you like for the connection. Then click the OK button. 40

44 Figure In the Connect To dialog box, choose the COM port that your mobile phone or GSM/GPRS modem is connecting to in the Connect using combo box. For example, choose COM1 if your mobile phone or GSM/GPRS modem is connecting to the COM1 port. Then click the OK button. (Sometimes there will have more than one COM port in the Connect using combo box. To know which COM port is used by your mobile phone or GSM/GPRS modem, follow the procedure below: In Windows 98: Go to Control Panel -> Modem. Then click the Diagnostics tab. In the list box, you can see which COM port the mobile phone or GSM/GPRS modem is connected to. In Windows 2000 and Windows XP: Go to Control Panel -> Phone and Modem Options. Then click the Modems tab. In the list box, you can see which COM port the mobile phone or GSM/GPRS modem is connected to.) 41

45 . Figure The Properties dialog box comes out. Enter the correct port settings for your mobile phone or GSM/GPRS modem. Then click the OK button. (To find the correct port settings that should be used with your mobile phone or GSM/GPRS modem, one way is to consult the manual of your mobile phone or GSM/GPRS modem. Another way is to check the port settings used by the wireless modem driver that you installed earlier. To check the port settings used by the wireless modem driver on Windows 98, follow these steps: a. Go to Control Panel -> Modem. b. Select your mobile phone or GSM/GPRS modem in the list box. c. Click the Properties button. d. The Properties dialog box appears. The Maximum speeds field on the General tab corresponds to HyperTerminal's Bits per second field. Click the Connection tab and you can find the settings for data bits, parity and stop 42

46 bits. Click the Advanced button and you can find the setting for flow control. To check the port settings used by the wireless modem driver on Windows 2000 and Windows XP, follow these steps: a. Go to Control Panel -> Phone and Modem Options -> Modems tab. b. Select your mobile phone or GSM/GPRS modem in the list box. c. Click the Properties button. d. The Properties dialog box appears. Click the Advanced tab and then click the Change Default Preferences button. e. The Change Default Preferences dialog box appears. The Port speed field on the General tab corresponds to HyperTerminal's Bits per second field. You can also find the setting for flow control on the General tab. On the Advanced tab, you can find the settings for data bits, parity and stop bits.) 43

47 Figure Type "AT" in the main window. A response "OK" should be returned from the mobile phone or GSM/GPRS modem. Type "AT+CPIN?" in the main window. The AT command "AT+CPIN?" is used to query whether the mobile phone or GSM/GPRS modem is waiting for a PIN (personal identification number, i.e. password). If the response is "+CPIN: READY", it means the SIM card does not require a PIN and it is ready for use. If your SIM card requires a PIN, you need to set the PIN with the AT command "AT+CPIN=<PIN>". 44

48 Figure 3.5 If you get the responses above, your mobile phone or GSM/GPRS modem is wo rking properly. You can start typing your own AT commands to control the mobile phone or GSM/GPRS modem. 45

49 3.5 Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages After testing the communication between the PC and GSM/GPRS modem/mobile phone, the next thing that you may want to do is to check if the GSM/GPRS modem or mobile phone supports the use of AT commands to send, receive and read SMS messages. Most GSM/GPRS modems support all three functions. However, only some mobile phones support all of them. Sending SMS Messages To find out whether a GSM/GPRS modem or mobile phone supports the sending of SMS messages through AT commands, you have to: 1. Use the AT command +CSMS (command name in text: Select Message Service) to check whether mobile-originated SMS messages are supported. 2. Perform test operations to check whether +CMGS (command name in text: Send Message) and/or +CMSS (command name in text: Send Message from Storage) are supported. (You may want to check the AT commands +CMGW [command name in text: Write Message to Memory] and +CMGD [command name in text: Delete Message] in addition as they are sometimes used together with +CMSS.) 46

50 Receiving SMS Messages and Reading SMS Messages from Message Storage To find out whether a GSM/GPRS modem or mobile phone supports the receiving and reading of SMS messages through AT commands, you have to: 1. Use the AT command +CSMS (command name in text: Select Message Service) to check whether mobile-terminated SMS messages are supported. 2. Perform test operations to check whether +CNMI (command name in text: New Message Indications to TE), +CMGL (command name in text: List Messages) and/or +CMGR (command name in text: Read Message) are supported. If the GSM/GPRS modem or mobile phone supports the +CNMI AT command, it can send a notification or directly forward the message to the PC whenever a new SMS message arrives. If the GSM/GPRS modem or mobile phone does not support +CNMI but supports +CMGL and/or +CMGR, the PC has to poll the GSM/GPRS modem or mobile phone repeatedly in order to know if any new SMS messages have arrived. [4] 47

51 CHAPTER 4: HITACHI LCD DISPLAY Figure

52 4.1 Features An HD44780 Character LCD is a de facto industry standard liquid crystal display (LCD) display device designed for interfacing with embedded systems. These screens come in a variety of configurations including 8x1, which is one row of eight characters, 16x2, and 20x4. The most commonly manufactured configuration is 40x4 characters, which requires two individually addressable HD44780 controllers with expansion chips as the HD44780 can only address up to 80 characters. These LCD screens are limited to text only and are often used in copiers, fax machines, laser printers, industrial test equipment, networking equipment such as routers and storage devices..character LCDs use a standard 14-pin interface and those with backlights have 16 pins. The pin outs are as follows: 1. Ground 2. VCC (+3.3 to +5V) 3. Contrast adjustment (VO) 4. Register Select (RS). RS=0: Command, RS=1: Data 5. Read/Write (R/W). R/W=0: Write, R/W=1: Read 6. Clock (Enable). Falling edge triggered 7. Bit 0 (Not used in 4-bit operation) 8. Bit 1 (Not used in 4-bit operation) 9. Bit 2 (Not used in 4-bit operation) 10. Bit 3 (Not used in 4-bit operation) 11. Bit Bit Bit 6 49

53 14. Bit Backlight Anode (+) 16. Backlight Cathode (-) Character LCDs can operate in 4-bit or 8-bit mode. In 4 bit mode, pins 7 through 10 are unused and the entire byte is sent to the screen using pins 11 through 14 by sending 4-bits (nibble) at a time. 50

54 CHAPTER 5: BLOCK DIAGRAM Figure

55 5.1 Block diagram explanation Working of Block Diagram A mobile interfaced to P89V51RD2 microcontroller.the user has his password stored in front of his id number in the memory of µc. The User has to send his voting information via sms to the mobile interfaced to the microcontroller. The µc will consider a vote if the password of a person matches to his election id. When a vote gets approved it gets locked and the user account will be expired. The mobile interfaced to the µc will send an acknowledgment message when the vote is granted; if something goes wrong then µc will send a negative acknowledgment message via sms to the user. If the password of the person is entered in the same order, there will be a positive vote given to the candidate to which the voter is voting. If the password is in the reverse manner, there will be a negative voting against the candidate voted. This is done in order to reduce the risk of forcible voting. The factor of negative voting is kept to be 1/3 rd i.e 1/3 rd vote will be subtracted from the candidate s vote to compensate the cheating. This factor is determined after a lot of probability work done so that no one can determine the winner just on the basis of negative voting. This cannot help in judging the output of the election. Thus we can completely rely on the system. 52

56 5.2. Circuit diagram Figure 15 Figure

57 5.3 Circuit diagram explanation Here port 2 is connected to the lcd to display data from the microcontroller to the lcd. The virtual terminal is used to send and receive data via serial port and is used instead of a GSM module. The HEX file of the program is loaded into the controller and the clock frequency and baud rates of all the devices are adjusted so that they work in synchronization. Some pins of port 0 are used to give the write and latching commands to the lcd. 54

58 5.3.1 POWER SUPPLY 7805 VOLTAGE REGULATOR The 78xx (also sometimes known as LM78xx) series of devices is a family of self-contained fixed linear voltage regulator integrated circuits. The 78xx family is a very popular choice for many electronic circuits which require a regulated power supply, due to their ease of use and relative cheapness. When specifying individual ICs within this family, the xx is replaced with a two-digit number, which indicates the output voltage the particular device is designed to provide (for example, the 7805 has a 5 volt output, while the 7812 produces 12 volts). The 78xx line are positive voltage regulators, meaning that they are designed to produce a voltage that is positive relative to a common ground. There is a related line of 79xx devices which are complementary negative voltage regulators. 78xx and 79xx ICs can be used in combination to provide both positive and negative supply voltages in the same circuit, if necessary.78xx ICs have three terminals and are most commonly found in the TO220 form factor, although smaller surface-mount and larger TO3 packages are also available from some manufacturers. These devices typically support an input voltage which can be anywhere from a couple of volts over the intended output voltage, up to a maximum of 35 or 40 volts, and can typically provide up to around 1 or 1.5 amps of current (though smaller or larger packages may have a lower or higher current rating). Figure

59 5.3.2 BRIDGE RECTIFIER A diode bridge is an arrangement of four diodes in a bridge configuration that provides the same polarity of output for either polarity of input. When used in its most common application, for conversion of an alternating current (AC) input into direct current a (DC) output, it is known as a bridge rectifier. A bridge rectifier provides full-wave rectification from a two-wire AC input, resulting in lower cost and weight as compared to a rectifier with a 3-wire input from a transformer with a center-tapped secondary winding. Figure

60 5.4. Flowchart 57

61 Figure

62 5.5 Hardware used Cxx test board kit Figure