16120651 Fingerprint Authentication With 8051

CHAPTER-1 PROJECT INTRODUCTION 1.1 INTRODUCTION Authentication plays a very critical role in security-related applications like e-commerce. There are a number of methods and techniques for accomplishing this key process. In this regard, biometrics is gaining increasing attention these days. Security systems, having realized the value of biometrics, use biometrics for two basic purposes: to verify or identif y users. There is a number of biometrics and different applications need different biometrics. Biometric is the most secure and convenient authentication tool. It can not be borrowed, stolen, or forgotten and forging one is practically impossible. Biometrics measure individual's unique physical or behavioral characteristics to recognize or authenticate their identity. Common physical biometrics includes fingerprints, hand or palm geometry, retina, iris, and facial characteristics. Behavioral characters characteristics include signature, voice, keystroke pattern, and gait. Project deals with Identification, Authentication and Setup of Security System using FIM 3030 Biometrics and 8051 Microcontroller. Beside Biometrics and 8051 Microcontroller the major components required are LCD, RTC Section (for real time clock updates), General purpose PCB, Relay section (for opening and closing of security doors) and Personal Computer etc. The interfacing between 8051-LCD, 8051-RTC, 8051 - FIM 3030 Biometrics Module (Thumb Geometry recognition) and FIM 3030 Biometric Module – Personal Computer is to be implemented. The details about each module are given in next sections of this report.

1.2 WORKING OF THE PROJECT The working of the project is explained with the help of block diagram.

Block diagram: 1

Figure 1.1 Block diagram of the system There are two modes 1. Registration mode 2. User mode In first mode, i.e., the registration mode, system communicates with personal computer for creating and maintenance of data base. This mode can be selected using mode switches available on system. In this mode scanner scans the image of thumb impression of the person and generates its bit pattern matrix according to the key points in thumb geometry and than stores it in memory available in FIM 3030 Biometrics Module known as user’s space. Only administrator has authority to register the new person. In second mode, i.e., the user mode, system breaks contact with personal 2

computer. This mode can be selected with the same switches that are mode switches on system. In this mode system again scans the thumb geometry of the person making contact with scanner for identification and start matching with the existing data base maintained during registration mode. If system recognizes the person than it would grant the access through doors according to his/her designation else access denied message would be shown on LCD and according to persons designation access through doors will be provided. For a student only door number 1 gets open. For a teacher/staff member door number 1 and 2 gets open. For an administrator all three doors i.e. door no. 1, 2 & 3 gets open for approximately 6seconds. As only single door lock is available, we are using electrical bulbs for door no. 2 and 3.System also includes real time clock updates, which updates our system clock continuously. I²C protocols are used to access real time updates from RTC (real time clock) section. Central control unit of system is Microcontroller 8051, which is also interfaced with RTC Section. Codes for whole procedure followed by system are retune in Embedded C programming language. Keil MicroVision3 Integrated Development Environment is used to compile whole program and Flash magic is used to burn the program code Hex file. Whole project is divided in 6 chapters. Second chapter describes the microcontroller 8051’s architecture. Third chapter describes the biometrics basics and the FIM system. Forth chapter describes the fundamentals of serial communication. Fifth chapter describes the hardware description of whole project. At last in appendix codes are shown related to the project.

Summary The project deals with the identification, authentication and setup of security system using Biometrics module. Main aim of project is to give access to the user according to their designation and to maintain data base. Working of project has been discussed. Finally, this chapter gives the over view of compete project working. 3

CHAPTER-2 THE 8051 MICROCONTROLLER 2.1 GENERAL In this chapter, the 8051 family, 8051 assembly language programming, loop and I/O port programming, 8051 addressing modes, arithmetic instructions, 8051 hardware connection and Intel hex file have been discussed.

2.2 THE 8051 FAMILY In 1981, Intel Corporation introduced an 8-bit microcontroller called the 8051. This microcontroller had 128 bytes of RAM, 4K bytes of on-chip ROM, two timers, one serial port, and four ports (each 8-bits wide) all on a single chip. The 8051 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at a time. Data larger than 8 bits has to broken into 8-bit pieces to be processed by the CPU. The 8051 has a total of four I/O ports, each 8 bits wide. Although the 8051 can have a maximum of 64K bytes of onchip ROM, many manufacturers have put only 4K bytes on the chip. There are different flavors of the 8051 in terms of speed and amount of on-chip ROM, but they are all compatible with the original 8051 as far as the instructions are concerned. The various members of the 8051 family are 8051 microcontroller, 8052 microcontroller and 8031 microcontroller. Block Diagram:

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Figure 1.2 Block diagram of inside the microcontroller 8051

2.2.1 8051 Microcontroller The 8051 is the original member of the 8051 family. Figure 2.1 shows the block diagram of the 8051 microcontroller. The AT89C51 is a low-power, high-performance CMOS 8bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which 5

provides a highly-flexible and cost-effective solution to many embedded control applications. The AT89C51 provides the following standard features: 4Kbytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bittimer/counters, five vector two-level interrupt architecture, a full duplex serial port, and on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.

2.2.2 Pin Description VCC Supply voltage.

GND Ground.

Port 0 Port 0 is an 8-bit open- drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as highimpedance inputs. Port 0 may also be configured to be the multiplexed low- order address/data bus during accesses to external program and data memory. In this mode P0 has internal pull-ups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pull-ups are required during program verification.

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Figure 2.2 Pin diagram for microcontroller 8051

Port 1 Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 1 also receives the low-order address bytes during Flash programming and verification. 7

Port 2 Port 2 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that uses 16-bit addresses (MOVX @DPTR). In this application, it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.

Port 3 Port 3 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 3 output buffer scan sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups. Port 3 also serves the functions of various special features of the AT89C51 as listed below:

Table 2.1function of port 3 8

Port 3 also receives some control signals for Flash programming and verification.

RST Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device.

ALE/PROG Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.

PSEN Program Store Enable is the read strobe to external program memor y. When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.

EA/VPP External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that 9

require 12-volt VPP.

XTAL1 Input to the inverting oscillator amplifier and input to the internal clock operating circuit.

XTAL2 Output from the inverting oscillator amplifier. Oscillator Characteristics XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a quartz crystal or cer amic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown.

Figure 2.3 Cr ystal Oscillator Connections There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed.

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2.2.3 Programming of Microcontroller 8051 We are using embedded C programming language to program the central unit i.e. microcontroller 8051, so that it perfor ms the specific task according to the requirement.

Need of C: Compiler produces hex file that we download into ROM of microcontroller. The size of hex file produced by compiler is one of the main concerns of microcontroller programmers for two reasons: 1. Microcontroller has limited on -chip ROM 2. The code space for 8051 is limited to 64 KB Programming in assembly language is tedious and time consuming. C is a high level programming language that is portable across many hardware architectures. So for following reasons we use C: 1. It is easier and less time consuming to write in C than assembly. 2. C is easier to modify and update. 3. You can use code available in function libraries. 4. C code is portable to other microcontrollers with little or no modification. We use reg51.h as a header file as “#include ”. These files contain all the definitions of the 80C51 registers. This file is included in your project and will be assembled together with the compiled output of your C program. C data types for 8051: 1. Unsigned char is 8-bit data type ranging 0-255 (0-FFH) 2. Signed char is 8-bit data type that uses most significant bit to represent the – or + value. We have only 7-bits for the magnitude of the signed numbers giving us values from -128 to +127. 11

3. Unsigned int is 16-bit data type ranging 0-65535(0-FFFFH). 4. Signed int is 16-bit data type that uses most significant bit to represent the – or + value. We have only 15-bits for the magnitude of the signed numbers giving us values from -32768 to +32767. Sbit is a keyword designed to access single bit addressable registers. It allows to the single bits of the SFR registers. We can use sbit to access the individual bits of the ports as “Sbit mybit=P1^0”. This controls the D0 of port P1. Bit data type allows access to the single bits of bit - addressable memory spaces 20-2FH. Sfr, the bit data type is used for the bit addressable section of RAM space 20-2FH. Bitwise operators are AND (&), OR (|), EX-OR (^), Inverter (~), Shift Right (>>) and Shift left (<<).

Summary In this chapter the 8051 Families, Architecture of 8051 Microcontroller, Pin description and Embedded C programming basics have been discussed.

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CHAPTER-3 BIOMETRICS 3.1 INTRODUCTION Humans recognize each other according to their various characteristics for ages. We recognize others by their face when we meet them and by their voice as we speak to them. Identity verification (authentication) in computer systems has been tr aditionally based on something that (key, magnetic or chip card) or (PIN, password). Things like keys or cards, however, tend to get stolen or lost and passwords are often forgotten or disclosed. To achieve more reliable verification or identification we should use something that really characterizes the given person. Biometrics offer automated methods of identity verification or identification on the principle of measurable physiological or behavioral characteristics such as a fingerprint or a voice sample. The characteristics are measurable and unique. These characteristics should not be duplicable, but it is unfortunately often possible to create a copy that is accepted by the biometric system as a true sample. This is a typical situation where the level of security provided is given as the amount of money the impostor needs to gain an unauthorized access. We have seen biometric systems where the estimated amount required is as low as $100 as well as systems where at least a few thousand dollars are necessar y. Biometric systems can be used in two different modes. Identity occurs when the user claims to be already enrolled in the system (presents an ID card or login name); in this case the biometric data obtained from the user is compared to the user ’s data already stored in the database. Identification occurs when the identity of the user is a priori unknown. In this case the user’s biometric data is matched against all the records in the database as the user can be anywhere in the database or he/she actually does not have to be there at all. 13

It is evident that identification is technically more challenging and costly. Identification accuracy generally decreases as the size of the database grows. For this reason records in large databases are categorized according to a sufficiently discriminating characteristic in the biometric data. Subsequent searches for a particular record are searched within a small subset only. This lowers the number of relevant records per search and increases the accuracy (if the discriminating characteristic was properly chosen). Before the user can be successfully verified or identified by the system, he/she must be registered with the biometric system. User ’s biometric data is captured, processed and stored. As the quality of this stored biometric data is crucial for further authentications, there are often several (usually 3 or 5) biometric samples used to create user’s master template. The process of the user’s registration with the biometric system is called enrollment.

3.1.1 What to measure? Most significant difference between biometric and traditional technologies lies in the answer of the biometric system to an authentication/identification request. Biometric systems do not give simple yes/no answers. While the password either is ’abcd’ or not and the card PIN 1234 either is valid or not, no biometric system can verify the identity or identify a person absolutely. The person’s signature never is absolutely identical and the position of the finger on the fingerprint reader will vary as well. Instead, we are told how similar the current biometric data is to the record stored in the database. Thus the biometric system actually says what is the probability of these two biometric samples come from the same person. Biometric technologies can be divided into 2 major categor ies according to what they measure: 1. Devices based on physiological characteristics of a person (such as the fingerprint or hand geometry). 2. Systems based on behavioral characteristics of a person (such as signature 14

dynamics). Biometric systems from the first categor y are usually more reliable and accurate as the physiological char acteristics are easier to repeat and often are not affected by current (mental) conditions such as stress or illness. One could build a system that requires a 100%match each time. Yet such a system would be practically useless, as only very few users (if any) could use it. Most of the users would be rejected all the time, because the measurement results never are the same. We have to allow for some variability of the biometric data in order not to reject many authorized users. However, the greater variability we allow the greater is the probability that an impostor with a similar biometric data will be accepted as an authorized user. The variability is usually called a (security) threshold or a (security) level. If the variability allowed is small then the security threshold or the security level is called high and if we allow for greater variability then the security threshold or the security level is called low.

3.1.2 Biometric techniques There are lots of biometric techniques available nowadays. A few of them are in the stage of the research only (e.g. the odor analysis), but a significant number of technologies is already mature and commercially available (at least ten different types of biometrics are commercially available nowadays: fingerprint, finger geometry, hand geometry, palm print, iris pattern, retina pattern, facial recognition, voice comparison, signature dynamics and typing rhythm).

3.1.3 Fingerprint technologies Fingerprint identification is perhaps the oldest of all the biometric techniques. Fingerprints were used already in the Old China as a means of positively identifying a person as an author of the document. Their use in law enforcement since the last century is well known and actually let to an association fingerprint = crime. This caused some worries about the user acceptance of fingerprint-based systems. The situation improves as these systems spread around and become more common. Fingerprint readers before we 15

can proceed any further we need to obtain the digitalized fingerprint. The traditional method uses the ink to get the fingerprint onto a piece of paper. This piece of paper is then scanned using a traditional scanner. This method is used only rarely today when an old paper-based database is being digitalized, scanning a fingerprint found on a scene of a crime is being processed or in law enforcement AFIS systems. Otherwise modern live fingerprint readers are used. They do not require the ink anymore. These live fingerprint readers are most commonly based on optical, thermal, silicon or ultrasonic principles.

Figure 3.1 Optical Scanner All the optical fingerprint readers comprise of the Source of light, the light sensor and a special reflection surface that changes the reflection according to the pressure. Some of the readers are fitted out with the processing and memory chips as well. Optical finger print readers are the most common at present. They are based on reflection changes at the spots where the finger papillary lines touch the reader’s surface. The size of the optical fingerprint readers typically is around 10 x 10 x 5 centimeters. It is difficult to minimize them much more as the reader has to comprise the source of light, reflection surface and the light sensor. The optical fingerprint readers work usually reliably, but sometimes have problems with dust if heavily used and not cleaned. The dust may cause latent fingerprints, which may be accepted by the reader as a real fingerprint. Optical fingerprint readers cannot be fooled by a simple picture of a fingerprint, but any 3D fingerprint model makes a significant problem, all the reader checks is the pressure. A few readers are therefore equipped with additional detectors of finger aliveness.

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Figure 3.2 Fingerprint bitmap Optical readers are relatively cheap and are manufactured by a great number of manufacturers. The field of optical technologies attracts many newly established firms (e.g., American Biometric Company, Digital Persona) as well as a few big and well -known companies (such as HP, Philips or Sony). Optical fingerprint readers are also often embedded in keyboards, mice or monitors.

Figure 3.3 Optical fingerprint reader Silicon technologies are older than the optical technologies. They are based on the capacitance of the finger. The dc-capacitive silicon fingerprint sensors consist of rectangular arrays of capacitors on a silicon chip. One plate of the capacitor is the finger; the other plate is a tiny area of metallization (a pixel) on the chip’s surface. One places his/her finger against the surface of the chip (actually against an insulated coating on the chip’s surface). The ridges of the fingerprint are close to the nearby pixels and have high capacitance to them. The valleys are more distant from the pixels nearest them and therefore have lower capacitance. Such an array of capacitors can be placed onto a chip as small as 15 x 15 x 5 mm and thus is ideal for miniaturization. A PCMCIA card (the triple height of a credit card) with a silicon fingerprint reader is already available. Integration of a fingerprint reader on a credit card-sized smartcard was not achieved yet, but it is expected in the near future. Silicon fingerprint readers are popular also in mobile phones and laptop computers due to 17

the small size. The fingerprint bitmap obtained from the silicon reader is affected by the finger moisture as the moisture significant in uences the capacitance. This often means that too wet or dry finger do not produce bitmaps with a sufficient quality and so people with unusually wet or dry finger do not produce bitmaps with a sufficient quality and so people with unusually wet or dr y finger have problems with these silicon fingerprint readers. Both optical and silicon fingerprint readers are fast enough to capture and display the fingerprint in real time. The typical resolution is around 500 DPI.Ultrasonic fingerprint readers are the newest and least common. They use ultr asound to monitor the finger surface. The user places the finger on a piece of glass and the ultr asonic sensor moves and reads whole the fingerprint. This process takes one or two seconds. Ultrasound is not disturbed by the dirt on the finger so the quality of the bitmap obtained is usually fair. Ultrasonic fingerprint readers are manufactured by a single company nowadays. This company (Ultra Scan Inc.) owns multiple patents for the ultrasonic technology. The readers produced by this company are relatively big (15 x15 x 20 centimeters), heavy, noisy and expensive (with the price around $2500). They are able to scan fingerprint at 300, 600 and 1000 DPI (according to the model). Fingerprint processing Fingerprints are not compared and usually also not stored as bitmaps. Fingerprint matching techniques can be placed into two categories: minutiaebased and correlation based. Minutiae-based techniques find the minutiae points’ first and then map their relative placement on the finger. Minutiae are individual unique characterminutiae istics within the fingerprint pattern such as ridge endings, bifurcations, divergences, dots or islands (see the picture on the following page). In the recent years automated fingerprint comparisons have been most often based on minutiae. The problem with minutiae is that it is difficult to extract the minutiae points accurately when the fingerpr int is of low quality. This method also does not take into account the global pattern of ridges and furrows. The correlation-based method is able to 18

correlation based overcome some of the difficulties of the minutiae-based approach. However, it has some of its own shortcomings. Correlation-based techniques require the precise location of a registration point and are affected by image translation and rotation.

Loop Arch

Whorl Figure 3.4 Loop, Arch& Whorl

The loop is the most common type of fingerprint pattern and accounts for about 65% of all prints. The arch pattern is a more open curve than the loop. There are two types of arch patterns: the plain arch and the tented arch. Whorl patterns occur in about 30% of all fingerprint and are defined by at least one ridge that makes a complete circle. The readability of a fingerprint depends on a variety of work and environmental factors. These include age, gender, occupation and race. A young, female, Asian mineworker is seen as the most difficult subject. A surprisingly high proportion of the populations have missing finger, with the left forefinger having the highest percentage at 0.62%. There are about 30 minutiae within a typical fingerprint image obtained by a live fingerprint reader. The number and spatial distribution of minutiae varies according to the quality of the fingerprint image, finger pressure, moisture and placement. In the decision process, the biometric system tries to find minutiae transformation between the current distribution and the stored template. The matching decision is then based on the possibility and complexity of the necessary transformation. The decision usually takes from 5 milliseconds to 2 seconds.

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Figure 3.5 Fingerprint ridge These are not continuous, straight ridges. Instead they are broken, forked, changed directionally, or interrupted. The points at which ridges end, fork and change are called minutia points and these minutia points provide unique, identifying information. There area number of types of minutia points. The most common are ridge endings and ridge bifurcations (points at which a ridge divides into two or more branches). The speed of the decision sometimes depends on the security level and the negative answer very often takes longer time than the positive one (sometimes even 10 times more). There is no direct dependency between the speed and accuracy of the matching algorithm according to our experience. We have seen fast and accurate as well as slow and less accurate matching algorithms. The minutiae found in the fingerprint image are also used to store the fingerprint for future comparisons. The minutiae are en- templates coded and often also compressed. The size of such a master template usually is between 24 bytes and one kilobyte.

Figure 3.6 The minutiae matching The minutia matching is a process where two sets of minutiae are compared to decide whether they represent the same finger or not. Fingerprints contain a large amount of data. Because of the high level of data present in the image, it is possible to eliminate false matches and reduce the number of possible 20

matches to a small fraction. This means that the fingerprint technology can be used for identification even within large databases. Fingerprint identification technology has undergone an extensive research and development since the seventies. The initial reason for the effort was the response to the FBI requirement for an identification search system. Such systems are called Automated Fingerprint Identification Systems (AFIS) and are used to identif y individuals in large AFIS databases (typically to find the offender of a crime according to a fingerprint found at the crime scene or to identify a person whose identity is unknown). AFIS systems are operated by professionals who manually intervene the minutiae extraction and matching process and thus their results are really excellent. The typical access control systems, on the other side, are completely automated. Their accuracy is slightly worse. The quality of the fingerprint image obtained by an automated fingerprint reader from an inexperienced (non-professional) user is usually lower. Access control systems Fingerprint readers often do not show any fingerprint preview and so the users do not know if the positioning and pressure of the finger is correct. The automatic minutiae extraction in a lower quality image is not perfect yet. Thus the overall accuracy of such a system is lower. Some newer systems are based not only on minutiae extraction; they use the length and position of the papillary lines as well. A few system take into account even pores (their spatial distribution), pores but the problem with pores is that they are too dependent on the fingerprint image quality and finger pressure. Most of the biometric fingerprint systems use the fingerprint reader to provide for the fingerprint bitmap image only, whole the processing and matching is done by a software that runs on a computer (the software is often available for Microsoft Windows operating systems only). There are currently only very few fingerprint devices that does all the processing by the hardware. The manufacturers of the fingerprint readers used to deliver the fingerprint processing software with the hardware. Today, the market specializes. Even if it is still possible to buy a fingerprint reader with a software package (this is the popular way especial for the low-end devices for home or office use) there are many manufacturers that produce fingerprint hardware only (e.g. fingerprint silicon chips by Thomson) or software companies that offer device-independent fingerprint processing software. Device 21

independent software is not bound to images obtained by one single input device, but their accuracy is very low if various input devices are mixed.

3.1.4 The layer model Although the use of each biometric technology has its own specific issues, the basic operation of any biometric system is very similar. The system typically follows the same set of steps. The typical steps separation of actions can lead to identifying critical issues and to improving security of the overall process of biometric authentication. The whole process starts with the enrollment:

3.1.5 First measurement (acquisition) This is the first contact of the user with the biometric system. The user’s biometric sample is obtained using an input device. The quality of the first biometric sample is crucial for further authentications of the user, so the quality of this biometric sample must be particularly checked and if the quality is not sufficient, the acquisition of the biometric sample must be repeated. It may happen that even multiple acquisitions do not generate biometric samples with quality is crucial sufficient quality. Such a user cannot be registered with the system. There are also mute people, people without finger or with injured eyes. Both these categories create a “failed to enroll “group of users. Users very often do not have any previous experiences with the kind of the biometric system they are being registered with, so their behavior at the time of the first contact with the technology is not natural. This negatively in uences the quality of the first measurement and that is why the first measurement is guided by a professional who explains the use of the biometric reader. Creation of master characteristics the biometric measurements are processed after the acquisition. The number of biometric samples necessary for further processing is based on the nature of the used biometric technology. Sometimes a single sample is sufficient, but often multiple biometric samples are required. The biometric characteristics are most commonly neither compared nor stored in the raw format (say as a bitmap). The raw 22

measurements contain a lot of noise or irrelevant information, which need not be stored. So the measurements are processed and only the important features are extracted and used. This significant reduces the size of the data. The process of feature extraction is not lossless and so the extracted features cannot be used to reconstruct the biometric sample completely. Storage of master characteristics after processing the first biometric sample and extracting the features, we have to store (and maintain) the newly obtained master template. Choosing a proper discriminating characteristic for the categorization of records in large databases can improve identification (search) tasks later on. There are basically 4 possibilities where to store the template: in a card, in the central database on a server, on a workstation or directly in an authentication terminal. The storage in an authentication terminal cannot be used for template must be encrypted large-scale systems, in such a case only the first two possibilities are applicable. If privacy issues need to be considered then the storage on a card has an advantage, because in this case no biometric data must be stored (and potentially misused) in a central database. The storage on a card requires a kind of a digital signature of the master template and of the association of the user with the master template. Biometr ic samples as well as the extracted features are very sensitive data and so the master template should be stored always encrypted no matter what storage is used. As soon as the user is enrolled, he/she can use the system for successful authentications or identification. This process is typically fully automated and takes the following steps:

Acquisition(s) The current biometric measurements must be obtained for the system to be able to make the comparison with the master template. These subsequent acquisitions of the user’s biometric measurements are done at various places where the authentication of the user is required. This might be user’s computer in the office, an ATM machine or a sensor in front of a door. For the best performance the kind of the input device used at the enrollment and for the subsequent acquisitions should be the same. Other conditions of use should also be as similar as possible with the conditions at 23

the enrollment. These include the background (face recognition), the background noise (voice verification) or the moisture (fingerprint). While the enrollment is usually guided by trained personnel, the subsequent biometric measurements are most commonly fully automatic and unattended. This brings up a few special issues. Firstly, the user needs to know how to use the device to provide the sample in the best quality. This is often not easy because the device does not show any preview of the sample obtained, so for example in the case of a fingerprint reader, the user does not know whether the positioning of the finger on the reader and the pressure is correct. Secondly, as the reader is left unattended, it is up to the reader to check that the measurements obtained really belong to live persons (the aliveness property). For example, a fingerprint reader aliveness test should tell if the fingerprint it gets is from a live finger, not from a mask that is put on top of a finger. Similarly, an iris scanner should make sure that the iris image it is getting is from a real eye not a picture of an eye. In many biometric techniques (e.g. fingerprinting) the further processing trusts the biometric hardware to check the aliveness of the person and provide genuine biometric measurements only. Some other systems (like the face recognition) check the user’s aliveness in software (the proper change of a characteristic with time). No matter whether hardware or software is used, ensuring that the biometric measurements are genuine is crucial for the system to be secure. Without the assumption of the genuine data obtained at the input we cannot get a secure system. It is not possible to formally prove that a reader provides only genuine measurements and this affects also the possibility of a formal proof attacks and of the security of whole the biometric system. The aliveness test of a person is not an easy task. New countermeasures are always to be followed by newer attacks. We do not even know how efficient the current countermeasures are against the attacks to come. Biometric readers are not yet the main target of sophisticated criminals. But then we can expect a wave of professional attacks. We have seen a few biometric readers where the estimated cost of an attack is as low as a few hundred dollars. The security of such a system is really poor Creation of new characteristics the biometric measurements obtained in the previous step is processed and new characteristics are created. The process of feature extraction is basically the same as in the case of the enrollment. Only a single biometric sample is usually available. This might mean that the number or quality of the features 24

extracted is lower than at the time of enrollment.

Comparison the currently computed characteristics are then compared with the characteristics obtained during enrollment. This process is ver y dependent on the nature of the biometric technology used. Sometimes the desired security threshold is a parameter of the matching process, sometimes the biometric system returns a score within range. If the system performs verification then the newly obtained characteristics are compared only with one master template (or with a small number of master templates, e.g. a set of master templates for a few different finger). For an identification request the new characteristics are matched against a large number of master templates (either against all the records in the database or if the database is clustered then against the relevant part of the database.

3.2 FIM30N General Descriptions 3.2.1 FIM30N is a low-price stand-alone Fingerprint Identification Device with many excellent features. It provides benefits such as high identification performance, low power consumption and RS-232 serial interface with the various commands for easy integration into a wide range of applications. It is a durable and compact device with fingerprint identification module containing NITGEN® optics-based fingerprint sensor inside.

Target Application 3.2.2 1. Door-lock system 2. Safe Box 3. Simple Access Controller 4. Vehicle Control 5. ATM , POS 6. And more

Basic Feature 3.2.3 25

Hardware Specification

Table 3.1 Hardware specification of FIM3030 Operation Specification

Table 3.2 Operational specification of FIM3030

Block Diagram 3.2.4 26

Figure 3.7 RS-232C communication data consist of 8-bit data, no parity, 1-bit start-bit . and 1-bit stop-bit

Operation 3.2.5 1. Communication FIM30N has RS-232 serial communication port through that FIM30N communicates at the same time. These ports support 6 baud rate modes such as 9600, 14400, 19200, 38400, 57600, and 115200 bps. FIM30N follows NITGEN Serial Communication protocol.

2. User Data Area FIM30N provides 64 Kbytes flash memory. Using this memor y, host can save private data for specific usage. The caution is needed because the responsibility for reading, writing and erasing user data area is given to the host.

Key Function 3. 27

FIM30N supports 3 function key inputs such as Enroll Key, delete Key, and Identify Key. Using these keys without serial communication, enrollment, deletion, all deletion and identification operating can be executed.

External Port 3.2.6 1. External Interface Connection (JP1)

Table 3.3 Pin description of FIM 3030

20-Pin Sensor Connection (JP2) 2.

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Table 3.4 Pin Descr iption of sensor

NITGEN FIM - Ev Tool 3.2.7 It is tool provided by NITGEN with user fr iendly GUI for addition, deletion of records. It connects the module with the personal computer through C OM Port. Hence we can do the pr ocess of enrollment of new comer and maintain the data base.

Summary In this chapter the basics of Biometrics and its var ious types has been discussed. The specifications and wor king of FIM 3030 Nitgen Module with working Ev tool have been under stood thoroughly. .

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CHAPTER-4 SERIAL COMMUNICATION 4.1BASICS OF SERIAL COMMUNICATION Computer transfers data in two ways these are Parallel : Often 8 or more lines (wire conductors) are used to transfer data to a 1. device that is only few feet away. Serial : To transfer to a device located many meters away, the serial method is 2. used. The data is sent one bit at a time .

Figure 4.1 Mode of Communication At the transmitting end, the byte of data must be converted to serial bits using parallelin- serial-out shift register. At the receiving end, there is a serial-in-parallel-out shift register to receive the serial data and pack them into byte. When the distance is short, the digital signal can be transferred as it is on a simple wire and requires no modulation. If data is to be transferred on the telephone line, it must be converted from 0s and 1s to audio tones. This conversion is perfor med by a device called a modem, 30

“Modulator/demodulator”. Serial data communication uses two methods. First are synchronous method transfers a block of data at a time. Second is an asynchronous method transfer a single byte at a time. It is possible to write software to use either of these methods, but the programs can be tedious and long. There are special IC chips made by many manufacturers for serial communications namely UART (universal asynchronous Receiver-transmitter) & USART (universal synchronous-asynchronous Receiver-tr ansmitter).

Figure 4.2 Diagrammatic Simplex & Duplex Transmission A protocol is a set of rules agreed by both the sender and receiver. Asynchronous serial data communication is widely used for character-oriented transmissions where each character is placed in between start and stop bits, this is called framing and blockoriented data transfers use the synchronous method. The start bit is always one bit, but the stop bit can be one or two bits the start bit is always a 0 (low) and the stop bit(s) is 1 (high).

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Figure 4.3 Transmissions of Data Due to the extended ASCII characters, 8-bit ASCII data is common in modern PCs the use of one stop bit is standard. Assuming that we are transferring a text file of ASCII characters using 1 stop bit, we have a total of 10 bits for each character. In some systems in order to maintain data integrity, the parity bit of the character byte is included in the data frame. The rate of data transfer in serial data communication is stated in bps (bits per second). Another widely used terminology for bps is baud rate. As far as the conductor wire is concerned, the baud rate and bps are the same, and we use the terms interchangeably. The data transfer rate of given computer system depends on communication ports incorporated into that system. An interfacing standard RS232 was set by the Electronics Industries Association (EIA) in 1960. The standard was set long before the advent of the TTL logic family, its input and output voltage levels is not TTL compatible where a 1 is represented by -3 ~ -25 V, while a 0 bit is +3 ~ +25 V, making -3 to +3 undefined.

4.2MAX232 A line driver required to convert RS232 voltage levels to TTL levels, and vice versa. It includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a 32

single 5-V supply. Each receiver converts TIA/EIA-232-F inputs to 5-V TTL/CMOS levels. These receivers have a typical threshold of 1.3 V, a typical hysteresis of 0.5 V, and can accept ±30-V inputs. Each driver converts TTL/CMOS input levels into TIA/EIA232-F levels.

Pin Diagram

Figure 4.4 MAX 232 pin conf iguration

Connection with Microcontroller and DB9

Figure 4.5 Connections with Microcontroller and DB9 33

8051 has two pins that are used specifically for transferring and receiving data serially. These two pins are called TxD and RxD and are part of the port 3 group (P3.0 and P3.1).These pins are TTL compatible; therefore, they require a line driver to make them RS232 compatible. To allow data transfer between the PC and an 8051 system without any error, we must make sure that the baud rate of 8051 system matches the baud rate of the PC’s COM port.

4.3 REGISTER STRUCTURE SBUF Register: This is an 8-bit register used solely for serial communication. For a byte data to be transferred via the TxD line, it must be placed in the SBUF register. The moment a byte is written into SBUF, it is framed with the start and stop bits and transferred serially via the TxD line. SBUF holds the byte of data when it is received by 8051 RxD line. When the bits are received serially via RxD, the 8051 defames it by eliminating the stop and start bits, making a byte out of the data received, and then placing it in SBUF.

SCON Register: SCON is an 8-bit register used to program the start bit, stop bit, and data bits of data framing, among other things.

Table 4.1 Functions of various bits in SCON register 34

SM0, SM1 : They determine the framing of data by specif ying the number of bits per character, and the start and stop bits.

Table 4.2 Mode selection using SM0 & SM1

SM2: This enables the multiprocessing capability of the 8051. REN (receive enable): It is a bit-addressable register. When it is high, it allows 8051 to receive data on RxD pin. If low, the receiver is disables (transmit interrupt). When 8051 finishes the transfer of 8-bit character. It raises TI flag to indicate that it is ready to transfer another byte. TI bit is raised at the beginning of the stop bit RI (receive interrupt). When 8051 receives data serially via RxD, it gets rid of the start and stop bits and places the byte in SBUF register. It raises the RI flag bit to indicate that a byte has been received and should be picked up before it is lost. RI is raised halfway through the stop bit.

4.4I²C Philips Semiconductors developed the I²C bus over 20 years ago and has an extensive collection of specific use and general purpose devices. Originally, the I²C bus was designed to link a small number of devices on a single card, such as to manage the tuning of a car radio or TV. The maximum allowable capacitance was set at 400 pF to allow proper rise and fall times for optimum clock and data signal integrity with a top speed of 100 kbps. In 1992 the standard bus speed was increased to 400 kbps, to keep up with the ever-increasing performance requirements of new ICs. The 1998 I²C specification, 35

increased top speed to 3.4 Mbits/sec. All I²C devices are designed to be able to communicate together on the same two-wire bus and system functional architecture is limited only by the imagination of the designer. But while its application to bus lengths within the confines of consumer products such as PCs, cellular phones, car radios or TV sets grew quickly, only a few system integrators were using it to span a room or a building. The I²C bus is now being increasingly used in multiple card systems, such as a blade servers, where the I²C bus to each card needs to be isolatable to allow for card insertion and removal while the rest of the system is in operation, or in systems where many more devices need to be located onto the same card, where the total device and trace capacitance would have exceeded 400 pF.

New bus extension & control devices help expand the I²C bus beyond the 400 pF limit of about 20 devices and allow control of more devices, even those with the same address. These new devices are popular with designers as they continue to expand and increase the range of use of I²C devices in maintenance and control applications.

4.4.1 Features 1. I²C Only two bus lines are required: a serial data line (SDA) and a serial clock line (SCL). 2. Each device connected to the bus is software addressable by a unique address and simple master/slave relationships exist at all times; masters can operate as mastertransmitters or as master-receivers. 3. It’s a true multi-master bus including collision detection and arbitration to prevent data corruption if two or more masters simultaneously initiate data transfer. 4. Serial, 8-bit oriented, bi-directional data transfers can be made at up to 100 kbit/s in the Standard-mode, up to 400 kbit/s in the Fast-mode, or up to 3.4 Mbit/s in the High-speed mode. 5. On-chip filtering (50 ns) rejects spikes on the bus data line to preserve data integrity. 6. The number of ICs that can be connected to the same bus segment is limited only 36

by the maximum bus capacitive loading of 400 pF.

Communication Procedure 4.4.2 One IC that wants to talk to another must: 1. Wait until it sees no activity on the I²C bus. SDA and SCL are both high. The bus is ‘free’. 2. Put a message on the bus that says 'its mine' - I have STARTED to use the bus. All other ICs then LISTEN to the bus data to see whether they might be the one who will be called up (addressed). 3. Provide on the CLOCK (SCL) wire a clock signal. It will be used by all the ICs as the reference time at which each bit of DATA on the data (SDA) wire will be correcting (valid) and can be used. The data on the data wire (SDA) must be valid at the time the clock wire (SCL) switches from ‘low’ to 'high' voltage. 4. Put out in serial form the unique binary 'address'(name) of the IC that it wants to communicate with. 5. Put a message (one bit) on the bus telling whether it wants to SEND or RECEIVE data from the other chip. 6. Ask the other IC to ACKNOWLEDGE (using one bit) that it recognized its address and is ready to communicate. 7. After the other IC acknowledges all is OK, data can be transferred. 8. The first IC sends or receives as many 8-bit words of data as it wants. After every 8-bit data word the sending IC expects the receiving IC to acknowledge the transfer is going OK. 9. When all the data is finished the first chip must free up the bus and it does that by a special message called 'STOP'. It is just one bit of information transferred by a special ‘wiggling’ of the SDA/SCL wires of the bus. The bus rules say that when data or addresses are being sent, the DATA wire is only allowed to be changed in voltage (so, '1', '0') when the voltage on the clock line is LOW.

37

The 'start' and 'stop' special messages BREAK that rule, and that is how they are recognized as special. Any device with the ability to initiate messages is called a ‘master’. It might know exactly what other chips are connected, in which case it simply addresses the one it wants, or there might be optional chips and it then checks what’s there by sending each address and seeing whether it gets any response (acknowledge).

Theory of Operation 4.4.3 I²C is a low to medium speed serial bus with unimpressive list of features: 1. Resistant to glitches and noise 2. Supported by a large and diverse range of peripheral devices 3. A well-known robust protocol 4. A long track record in the field 5. A respectable communication distance which can be extended to longer distances with bus extenders 6. Compatible with a number of processors with integrated I²C ports ( micro 8,16,32 bits) in 8048, 80C51 or 6800 and 68xxx architectures 7. Easily emulated in software by any microcontroller 8. Available from an important number of component manufacturers

Figure 4.6 I²C hardware architecture 38

Bus Terminology 4.4.4 Transmitter - the device that sends data to the bus. A transmitter can either be a device that puts data on the bus of its own accord (a ‘master-transmitter ’), or in response to a request from data from another devices (a ‘slave-transmitter ’). Receiver - the device that receives data from the bus. Master - the component that initializes a transfer, generates the clock signal, and terminates the transfer. A master can be either a transmitter or a receiver. Slave - the device addressed by the master. A slave can be either receiver or transmitter. Multi-master - the ability for mor e than one master to co-exist on the bus at the same time without collision or data loss. Arbitration - the prearranged procedure that authorizes only one master at a time to take control of the bus. Synchronization - the prearranged procedure that synchronizes the clock signals provided by two or more masters. SDA - data signal line (Serial DAta) SCL - clock signal line (Serial CLock)

START and STOP Conditions 4.4.5 Within the procedure of the I²C bus, unique situations arise which are defined as START (S) and STOP (P) conditions.

39

Figure 4.7 I²C bus Overview START: A HIGH to LOW transition on the SDA line while SCL is HIGH STOP: A LOW to HIGH transition on the SDA line while SCL is HIGH The master always generates START and STOP conditions. The bus is considered to be busy after the START condition. The bus is considered to be free again a certain time after the STOP condition. The bus stays busy if a repeated START (Sr) is generated instead of a STOP condition. In this respect, the START (S) and repeated START (Sr) conditions are functionally identical. The S symbol will be used as a generic ter m to represent both the START and repeated START conditions, unless Sr is particularly relevant. Detection of START and STOP conditions by devices connected to the bus is easy if they incorpor ate the necessary interfacing hardware. However, microcontrollers with no such interface have to sample the SDA line at least twice per clock period to sense the transition.

Hardware configuration 4.4.6 Figure shows the hardware configuration of the I²C bus. The ‘bus’ wires are named SDA 40

(serial data) and SCL (serial clock). These two bus wires have the same configuration. They are pulled-up to the logic ‘high’ level by resistors connected to a single positive supply, usually +3.3 V or +5 V but designers are now moving to +2.5 V and towards 1.8 V in the near future. All the connected devices have open-collector (open-drain for CMOS - both terms mean only the lower transistor is included) driver stages that can transmit data by pulling the bus low, and high impedance sense amplifiers that monitor the bus voltage to receive data. Unless devices are communicating by turning on the lower transistor to pull the bus low, both bus lines remain ‘high’. To initiate communication a chip pulls the SDA line low. It then has the responsibility to drive the SCL line with clock pulses, until it has finished, and is called the bus ‘master’.

Bus Communication 4.4.7 Communication is established and 8-bit bytes are exchanged, each one being acknowledged using a 9th data bit generated by the receiving party, until the data transfer is complete. The bus is made free for use by other ICs when the ‘master’ releases the SDA line during a time when SCL is high. Apart from the two special exceptions of start and stop, no device is allowed to change the state of the SDA bus line unless the SCL line is low. If two masters try to start a communication at the same time, arbitration is perfor med to determine a “winner” (the master that keeps control of the bus and continue the transmission) and a “loser” (the master that must abort its transmission). The two masters can even generate a few cycles of the clock and data that ‘match’, but eventually one will output a ‘low’ when the other tries for a ‘high’. The ‘low’ wins, so ‘loser’ device withdraws and waits until the bus is freed again. There is no minimum clock speed; in fact any device that has problems to ‘keep up the pace’ is allowed to ‘complain’ by holding the clock line low. Because the device generating the clock is also monitoring the voltage on the SCL bus, it immediately ‘knows’ there is a problem and has to wait until the device releases the SCL line.

41

Address scheme 4.4.8 Any I²C device can be attached to the common I²C bus and they talk with each other, passing information back and forth. Each device has a unique 7-bit or 10-bit I²C address. For 7-bit devices, typically the first four bits are fixed, the next three bits are set by hardware address pins (A0, A1, and A2) that allow the user to modify the I²C address allowing up to eight of the same devices to operate on the I²C bus. These pins are held high to VCC, sometimes through a resistor, or held low to GND. The last bit of the initial byte indicates if the master is going to send (write) or receive (read) data from the slave. Each transmission sequence must begin with the start condition and end with the stop condition. On the 8th clock pulse, SDA is set ‘high’ if data is going to be read from the other device, or ‘low’ if data is going to be sent (write). During its 9th clock, the master releases SDA line to accomplish the Acknowledge phase. If the other device is connected to the bus, and has decoded and recognized its ‘address’, it will acknowledge by pulling the SDA line low. The responding chip is called the bus ‘slave’.

Figure 4.8 I²C Address scheme

42

Terminology for bus transfer 4.4.9

Figure 4.9 I²C Read Write operations 1. F (FREE) - the bus is free; the data line SDA and the SCL clock are both in the high state. 2. S (START) or SR (Repeated START) - data transfer begins with a start condition (not a start bit). The level of the SDA data line changes from high to low, while the SCL clock line remains high. When this occurs, the bus is ‘busy’. 3. C (CHANGE) - while the SCL clock line is low, the data bit to be transferred can be applied to the SDA data line by a transmitter. During this time, SDA may change its state, as along as the SCL line remains low. 4. D (DATA) - a high or low bit of information on the SDA data line is valid during the high level of the SCL clock line. This level must be maintained stable during the entire time that the clock remains high to avoid misinterpretation as a Start or Stop condition. 5. P (STOP) - data transfer is terminated by a stop condition, (not a stop bit). This occurs when the level on the SDA data line passes from the low state to the high state, while the SCL clock line remains high. When the data transfer has been terminated, the bus is free once again. 43

4.5LCD Unit A liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. It is prized by engineers because it uses very small amounts of electric power, and is therefore suitable for use in battery-powered electronic devices. Each pixel consists of a column of liquid crystal molecules suspended between two transparent electrodes, and two polarizing filters, the axes of polarity of which are perpendicular to each other. Without the liquid crystals between them, light passing through one would be blocked by the other. The liquid crystal twists the polar ization of light entering one filter to allow it to pass through the other. The molecules of the liquid crystal have electric charges on them. By applying small electrical charges to transparent electrodes over each pixel or sub pixel , the molecules are twisted by electrostatic forces. This changes the twist of the light passing through the molecules, and allows varying degrees of light to pass (or not to pass) through the polarizing filters. Before applying an electrical charge, the liquid crystal molecules are in a relaxed state. Charges on the molecules cause these molecules to align themselves in a helical structure, or twist (the "crystal"). In some LCDs, the electrode may have a chemical surface that seeds the crystal, so it crystallizes at the needed angle. Light passing through one filter is rotated as it passes through the liquid crystal, allowing it to pass through the second polarized filter. A small amount of light is absorbed by the polarizing filters, but otherwise the entire assembly is transparent. When an electrical charge is applied to the electrodes, the molecules of the liquid cr ystal align themselves parallel to the electric field , thus limiting the rotation of entering light. If the liquid crystals are completely untwisted, light passing through them will be polarized perpendicular to the second filter, and thus be completely blocked. The pixel will appear unlit. By controlling the twist of the liquid crystals in each pixel, light can be allowed to pass though in varying amounts, correspondingly illuminating the pixel.

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Figure 4.10 LCD Display

Pin description of LCD 4.5.1 PIN

SYMBOL

I/

DESCRIPTIONS

O 1 VSS ----GROUND --2 VCC ----+5V POWER SUPPLY --3 VEE ----POWER SUPPLY TO CONTROL CONTRAST ---4 RS I RS=O TO SELECT COMMAND REGISTER RS=1 TO SELECT DATA REGISTER 5 R/W I R/W=0 FOR WRITE,R/W=1 FOR READ 6 E I/O ENABLE 8TO 14 DB0 TO DB14 I/O 8 BIT DATA BUSES Table 4.3 Pin description of LCD

4.5.2 LCD COMMAND CODES 1. 80 Force cursor to beginning to 1st line 45

2. C0 Force cursor to beginning to 2nd line 3. 38 2 lines and 5x7 matrix 4. 1C Shift the entire display to the right 5. 18 Shift the entire display to the left 6. 14 Shift cursor position to right 7. 10 Shift cursor position to left 8. F Display on, cursor blinking 9. E Display on, cursor blinking 10. C Display on, cursor off 11. A Display off, cursor on 12. 8 Display off, cursor off 13. 7 Shift display left 14. 5 Shift display right 15. 6 Increment cursor (shift cursor to right) 16. 4 Decrement cursor (shift cursor to lef t) 17. 2 Return home 18. 1 Clear display screen

Keil (IDE) MicroVision3 4.6 Keil Software development tools are used to create products for practically every industr y: consumer electronics, industrial control, networking, office automation, automotive, space exploration. Micro Vision Two is a second generation IDE that simplifies project development and application testing. With Micro Vision Two, we can easily create embedded applications in a mixture of C and assembly. Real-time applications benefit from our highly optimized C libraries and real-time kernels. MicroVision3 provides a centralized front-end interface for the compiler, assembler, linker, debugger, and other development tools. The Project Window in MicroVision3 displays the current target, groups, and source files that comprise our project. Rather than creating a single target for each project, MicroVision2allows multiple targets for each

46

project file. So, with a single project file, we can create a target for simulating, a target for our emulator, and a production target for programming into EPROM {E-PROM}. Each target is composed of one or more groups which are in turn composed of one or more source files. Groups let us divide the source files into functional blocks or assign source files to different team members. Options may be configured at each level of the project. This gives us a great deal of freedom and flexibility when organizing our application. In addition to the on-line help, MicroVision3 provides on-line versions of the development tool manuals as well as the device manuals. Keil C Compilers are based on the ANSI standard and include extensions necessary to support the 8051, 251, and 166 microcontroller families. The optimizer in our compiler is tuned for each specific architecture and provides the highest level of code density and execution speed. The Keil C compilers give full us control over our embedded platform. We decide which register banks are used, when to access certain memory areas, which variables are stored in bits, when and how to use special function registers, and so on. Without ever writing any assembly code we may even write interrupt service routines in C. Code generated by the Keil C Compiler compares with that of a professional assembly programmer. This is due to the level of optimizations that are performed. One such optimization is global register optimization. By analyzing which registers are used in each function, the compiler can better optimize register usage program-wide and generate smaller, faster programs. This is accomplished by iterative compilation steps during the make process. The MicroVision3 debugger is designed to make testing your programs as efficient as possible. While editing and debugging your programs, text and code attributes are displayed in the source window. As you step through your program, the current line is marked with a yellow arrow. Code coverage shows you which lines of your program have been executed. Green means the line has been run. Grey means is has not.

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Breakpoints are clearly marked in the source window. Red for enabled, white for disabled. These attributes make following program flow easier than ever. The features of the Micro Vision Two debugger don’t stop there. When simulating your programs, you not only get source-level, symbolic simulation. You also get on-chip peripheral simulation. Dialog boxes display the condition of all peripherals and on-chip components. The debugger supports a C macro language that you may use to simulate external hardware. We may create functions to simulate digital and analog input signals for your application. This lets you get straight to testing and debugging before the target hardware is available. With nothing more than the simulator and the macro language, you can create a high-fidelity simulation of your end product.

Summary In this chapter we have discussed the basics of serial communication. MAX232 has been discussed with it pin configuration and characteristics. The various registers used in serial communication have explained. The I²C protocols used for communication have explained. The LCD unit also discussed here.

CHAPTER-5 48

HARDWARE DESIGN RTC (REAL TIME CLOCK) 5.1 General description 5.1.1 The DS1307 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially through an I²C, bidirectional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. The DS1307 has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply. Timekeeping operation continues while the part operates from the backup supply.

Typical operating circuit 5.1.2

Figure 5.1 RTC connections with controller

Features 5.1.3

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1. Real-Time Clock (RTC) Counts Seconds, Minutes, Hours, Date of the Month, Month, Day the week, and Year with Leap-Year Compensation Valid Up to 2100. 2. 56-B yte, Batter y-Backed, General-Purpose RA with Unlimited Writes. I²C Serial Interface. 3. Programmable Square-Wave Output Signal. 4. Automatic Power-Fail Detect and Switch Circuit. 5. Consumes Less than 500nA in Battery-Backup Mode with Oscillator Running . 6. Optional Industrial Temperature Range: -40°C to +85°C . 7. Available in 8-Pin Plastic DIP or SO. 8. Underwriters Laboratories (UL) Recognized

Pin description 5.1.4

Figure 5.2 Pin diagram of DS1307 IC

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Table 4.4 Pin description of DS1307

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OrCAD schematic for system PCB connections 5.2 J26

J20 LS2 J1

VCC

1 J8

52 R9 3 3

1 J24

Q2

2

4

Q11 3

2

1 2

R8 CON3

J21 LS1

J23

VCC

1 52 R11 3 3

81 92 10 3

Q4

4 Q31

J10

J9

2 J6

11

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SW2

U1

13

6

2

14

7

3

J7

J2 C O N N TR B L K 8

C7

C9 C8

239

C O N N TR BL K 2 1 2

P0 .0 /A D 0 P 2 .0 / A8 J22 P0 .1 /A D 1 P 2 .1 / A9 4 437 233 LS3 P0 .2 /A D 2 P2 .2 /A 1 0 5 536 244 1 P0 .3 /A D 3 P2 .3 /A 1 1 6 635 255 52 P0 .4 /A D 4 P2 .4 /A 1 2 SW1 7 734 266 Q6 3 3 P0 .5 /A D 5 P2 .5 /A 1 3 8 833 277 Q5 4 P0 .6 /A D 6 P2 .6 /A 1 4 932 288 J3 1 P0 .7 /A D 7 P2 .7 /A 1 5 J5 2 CON8 1 10 1 R12 P1 .0 P 3 . 0 /R XD CON9 1 2 11 2 P1 .1 P 3 . 1 /TX D 2 3 12 3 P1 .2 P 3 .2 / IN T0 3 4 13 4 BT1 P1 .3 P 3 .3 / IN T1 4 5 14 5 P1 .4 P 3 . 4 /T0 5 6 15 6 P1 .5 P 3 . 5 /T1 C2 6 7 16 7 P1 .6 P3 .6 /W R C AP 7 8 P1 .7 P3 . 7 /R D J18 8 BA TTE R Y R1 19 30 XTA L 1 AL E/ PR O G C3 18 29 XTA L 2 P S EN 338

5

1

1

R10

211 222

R13

17

8

J16 C6 31 EA /V P P 9

12

C5

R ST C1 C AP

34 56 AT8 9 C 5 1

R7

78 J19 D 2 R E SI STO R 1J15

M A X2 3 2 2 U2

3 C4

4

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5

C10 6 R2

R3

R4R5

J17

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CON6

R E S IS TO R LED J11

J12

J13 J14 Title