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OVERVIEW
The hassles of vehicular commuting in crowded metropolitans in developing countries are many – having to wait hours together in traffic jams, taking tortuous detours due to on-road constructions, trying to spot speed breakers, navigating blind turns, one-ways and so on. Forked roads, railway crossings, sudden reverse bends and steep ascents and descents are just few of the road oddities that one may encounter on the average drive. At times, such road oddities are accompanied by road-signs. Mandatory road-signs enforce law, while Cautionary road-signs are installed in hazardous areas to avert accidents. Informative road-signs provide directions, locations and other information that is potentially useful to drivers in that locality. However, most vehicle drivers miss road signs more often than not. It is understandably difficult to keep an eye out for road signs when one should be focused on driving. The inconvenience is augmented by inadequate placement and poor noticeability of the signs. They are non-intelligent displays, and preventing traffic jams and providing personalized alerts are beyond their capacity.
Vehicle drivers must obey the speed limits at certain places like school zones and other important places but due to the lack of either invisibility of speed limit boards or due to their negligence they speed up which may lead to several number of accidents yearly in our country
With rapid increase in road transport throughout the world, there emerges a need for novel concepts and intelligent systems that enhance driving safety and convenience
1.2 LITERATURE SURVEY
The problems pervade much deeper than our daily hassles. Over 130,000 fatalities due to road accidents are reported annually in India alone (National Crime Records Bureau). Most road signs in India are replaced/ refurbished every 3 years. The Planning Division of the Traffic Management Center in a state installs road signs at costs between 4000 and 22000 INR ($80-$440) each. Since we are proposing a potential replacement, RFID tags have to come with a competitive life-span and cost. Since these RFID tags are meant to be installed on to roads/road-sides, they will receive sunlight for most part of the day. We can even fabricate the Tag using the solar power to reduce the cost in our future works.
By replacing road signs with RFID tags, and using in-vehicle RFID Reader-enabled modules to sense them, and providing tangible information to the driver. By using this Prototype there is a vast Reduction of Accidents and Safety Measures are ensured.
This System mainly consists of:
1. LPC2148 Microcontroller from ARM7 family acts as a central unit for working of the project.
2. RFID reader and tags, Voice module, LCD, DC Motor for speed management.
Using this system around we can eliminate around 90% of the Road accidents and the speed controlling system acts as an added enhancement so that by locating a speed control tag vehicle automatically reduces its swift and comes to a normal speed. So that the driver gets aware of any occurring hazard.
1.3 OBJECTIVE OF THE PROJECT
The objective was to replace road signs with RFID tags, and use in-vehicle RFID Reader-enabled modules to sense them, and provide tangible information to the driver and by automatically reducing the speed of the vehicle at speed limits so that any negligence drivers gets aware of speed restricted areas like school zones, Military premises, digged Roads etc.
The Prototype provides a good understanding of Road oddities and their safety measures. The equipped Voice module provides voice messages to the driver also with a Display LCD unit. So that the driver gets a overall information regarding an upcoming Traffic signs.
1.4 ORGANIZATION OF THE PROJECT REPORT
The report is organized into six chapters. The present chapter introduces the concept of the project work and the research issues. The literature survey of the problem is done and the objective of the project work is formulated.
Chapter 2 includes Introduction to Embedded Systems, its Classification, common components, design flow
Chapter 3 deals arm7 family,arm7tdmi processor core, LPC2148, microcontroller, features of LPC2148microcontroller,LPC2148,microcontroller,Pin diagram, architectural overview, interrupt controller, pin connect block, fast general purpose parallel i/o concept deals are also discussed
Chapter 4 describes about serial communication, RS 232, MAX 232 standards
Chapter 5 describes about Hardware components used like Power supply unit, RFID Tags and Readers, voice module, LCD display, DC Motors, L293D drivers.
Chapter 6 deals in Software requirements like, Software design introduction ORCAD design, KEIL C compiler, flash programmer, hardware, software are discussed.
Chapter 7 describes about Implementation Phase of the Project, Interfacing Diagrams and Results.
Chapter 8 deals with Conclusions and Future Scope.
INTRODUCTION TO EMBEDDED SYSTEMS
Many embedded systems have substantially different design constraints than desktop computing applications. No single characterization applies to the diverse spectrum of embedded systems. However, some combination of cost pressure, long life-cycle, real¬-time requirements, reliability requirements, and design culture dysfunction can make it difficult to be successful applying traditional computer design methodologies and tools to embedded applications. Embedded systems in many cases must be optimized for life-cycle and business-driven factors rather than for maximum computing throughput. There is currently little tool support for expanding embedded computer design to the scope of holistic embedded system design. However, knowing the strengths and weaknesses of current approaches can set expectations appropriately, identify risk areas to tool adopters, and suggest ways in which tool builders can meet industrial needs. If we look around us, today we see numerous appliances which we use daily, be it our refrigerator, the microwave oven, cars, PDAs etc. Most appliances today are powered by something beneath the sheath that makes them do what they do. These are tiny microprocessors, which respond to various keystrokes or inputs. These tiny microprocessors, working on basic assembly languages, are the heart of the appliances. We call them embedded systems. Of all the semiconductor industries, the embedded systems market place is the most conservative, and engineering decisions here usually lean towards established, low risk solutions. Welcome to the world of embedded systems, of computers that will not look like computers and won’t function like anything we are familiar with.
2.1 CLASSIFICATION
Embedded systems are divided into autonomous, realtime, networked & mobile categories.
Autonomous systems
They function in standalone mode. Many embedded systems used for process control in manufacturing units& automobiles fall under this category.
Real-time embedded systems
These are required to carry out specific tasks in a specified amount of time. These systems are extensively used to carry out time critical tasks in process control.
Networked embedded systems
They monitor plant parameters such as temperature, pressure and humidity and send the data over the network to a centralized system for on line monitoring.
Mobile gadgets
Mobile gadgets need to store databases locally in their memory. These gadgets imbibe powerful computing & communication capabilities to perform realtime as well as nonrealtime tasks and handle multimedia applications. The embedded system is a combination of computer hardware, software, firmware and perhaps additional mechanical parts, designed to perform a specific function. A good example is an automatic washing machine or a microwave oven. Such a system is in direct contrast to a personal computer, which is not designed to do only a specific task. But an embedded system is designed to do a specific task with in a given timeframe, repeatedly, endlessly, with or without human interaction.
Hardware
Good software design in embedded systems stems from a good understanding of the hardware behind it. All embedded systems need a microprocessor, and the kinds of microprocessors used in them are quite varied. A list of some of the common microprocessors families are: ARM family, The Zilog Z8 family, Intel 8051/X86 family, Motorola 68K family and the power PC family. For processing of information and execution of programs, embedded system incorporates microprocessor or micro- controller. In an embedded system the microprocessor is a part of final product and is not available for reprogramming to the end user. An embedded system also needs memory for two purposes, to store its program and to store its data. Unlike normal desktops in which data and programs are stored at the same place, embedded systems store data and programs in different memories. This is simply because the embedded system does not have a hard drive and the program must be stored in memory even when the power is turned off. This type of memory is called ROM. Embedded applications commonly employ a special type of ROM that can be programmed or reprogrammed with the help of special devices.
2.2 OTHER COMMON PARTS FOUND ON MANY EMBEDDED SYSTEMS
• UART& RS232
• PLD
• ASIC’s& FPGA’s
• Watch dog timer etc.
2.3 DESIGN PROCESS
Embedded system design is a quantitative job. The pillars of the system design methodology are the separation between function and architecture, is an essential step from conception to implementation. In recent past, the search and industrial community has paid significant attention to the topic of hardware-software (HW/SW) codesign and has tackled the problem of coordinating the design of the parts to be implemented as software and the parts to be implemented as hardware avoiding the HW/SW integration problem marred the electronics system industry so long. In any large scale embedded systems design methodology, concurrency must be considered as a first class citizen at all levels of abstraction and in both hardware and software. Formal models & transformations in system design are used so that verification and synthesis can be applied to advantage in the design methodology. Simulation tools are used for exploring the design space for validating the functional and timing behaviors of embedded systems. Hardware can be simulated at different levels such as electrical circuits, logic gates, RTL e.t.c. using VHDL description. In some environments software development tools can be coupled with hardware simulators, while in others the software is executed on the simulated hardware. The later approach is feasible only for small parts of embedded systems. Design of an embedded system using Intel’s 80C188EB chip is shown in the figure. Inorder to reduce complexity, the design process is divided in four major steps: specification, system synthesis, implementation synthesis and performance evaluation of the prototype.
2.3.1 SPECIFICATION
During this part of the design process, the informal requirements of the analysis are transformed to formal specification using SDL.
2.3.2 SYSTEM-SYNTHESIS
For performing an automatic HW/SW partitioning, the system synthesis step translates the SDL specification to an internal system model switch contains problem graph& architecture graph. After system synthesis, the resulting system model is translated back to SDL.
2.3.3 IMPLEMENTATION-SYNTHESIS
SDL specification is then translated into conventional implementation languages such as VHDL for hardware modules and C for software parts of the system.
2.3.4 PROTOTYPING
On a prototyping platform, the implementation of the system under development is executed with the software parts running on multiprocessor unit and the hardware part running on a FPGA board known as phoenix, prototype hardware for Embedded Network Interconnect Accelerators.
2.3.5 APPLICATIONS
Embedded systems are finding their way into robotic toys and electronic pets, intelligent cars and remote controllable home appliances. All the major toy makers across the world have been coming out with advanced interactive toys that can become our friends for life. ‘Furby’ and ‘AIBO’ are good examples at this kind. Furbies have a distinct life cycle just like human beings, starting from being a baby and growing to an adult one. In AIBO first two letters stands for Artificial Intelligence. Next two letters represents robot. The AIBO is robotic dog. Embedded systems in cars also known as Telematic Systems are used to provide navigational security communication & entertinment services using GPS, satellite. Home appliances are going the embedded way. LG electronics digital DIOS refrigerator can be used for surfing the net, checking e-mail, making video phone calls and watching TV.IBM is developing an air conditioner that we can control over the net. Embedded systems cover such a broad range of products that generalization is difficult. Here are some broad categories.
• Aerospace and defence electronics: Fire control, radar, robotics/sensors, sonar.
• Automotive: Autobody electronics, auto power train, auto safety, car information systems.
• Broadcast & entertainment: Analog and digital sound products, camaras, DVDs, Set top boxes, virtual reality systems, graphic products.
• Consumer/internet appliances: Business handheld computers, business network computers/terminals, electronic books, internet smart handheld devices, PDAs.
• Data communications: Analog modems, ATM switches, cable modems, XDSL modems, Ethernet switches, concentrators.
• Digital imaging: Copiers, digital still cameras, Fax machines, printers, scanners.
• Industrial measurement and control: Hydro electric utility research & management traffic management systems, train marine vessel management systems.
• Medical electronics: Diagnostic devices, real time medical imaging systems, surgical devices, critical care systems.
• Server I/O: Embedded servers, enterprise PC servers, PCI LAN/NIC controllers, RAID devices, SCSI devices.
• Telecommunications: ATM communication products, base stations, networking switches, SONET/SDH cross connect, multiplexer.
• Mobile data infrastructures: Mobile data terminals, pagers, VSATs, Wireless LANs, Wireless phones.
MICROCONTROLLER AT89S52
3.1AT89S52
3.1.1DESCRIPTION OF MICROCONTROLLER AT89S52
The AT89S52 is low power ,high performance CMOS 8-bit micro controller with 8KB of in system programmable flash memory. The device is manufactured.
Using atmel’s high density nonvolatile memory technology and is compatible with the industry standard 80C51 micro controller. 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 in syatem programmable flash one monolithic chip, the Atmel AT89S52 is a powerful micro controller. Which provides a highly flexible and cost effective solution to many embedded control applications.
3.1.2Features
Compatible with MCS-51 Products
8K Bytes of In-System Programmable (ISP) Flash Memory
o Endurance: 1000 Write/Erase Cycles
4.0V to 5.5V Operating Range
Fully Static Operation: 0 Hz to 33 MHz
Three-level Program Memory Lock
256K Internal RAM
32 Programmable I/O Lines
3 16-bit Timer/Counters
Eight Interrupt Sources
Full Duplex UART Serial Channel
Low-power Idle and Power-down Modes
Interrupt Recovery from Power-down Mode
Watchdog Timer
Dual Data Pointer
Power-off Flag
The AT89S52 provides the following standard features: 8KB of Flash 256 bytes of RAM, 32 I/O lines, watchdog timer, two data pointers, three 16-bit timer/counter, full duplex serial port, on chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for pertain down to zero frequency and supports two software selectable power saving modes. The idle mode stops the CPU while allowing the RAM timer/counter, serial port, and interrupt system to continue functioning. The power down saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.
3.1.4PIN DESCRIPTION OF MICROCONTROLLER 89S52
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 1sare written to port 0 pins, the pins can be used as high impedance inputs. Port 0 can 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
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. In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input P1.1/T2EX), respectively, as shown in the following table. Port 1 also receives the low-order address bytes during Flash programming and verification.
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. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2emits 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 buffers can sink/source four TTL inputs. When 1s are writt 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 AT89S52,