Introduction
Establishing the identity of a person is becoming critical in
our vast interconnected society. The
need for reliable person authentication techniques has increased in the wake of
high concerns about security and rapid advancement. Biometrics is described as
the science of recognizing an individual based on physiological or behavioral
traits. Biometrics has become popular over the traditional token based or
knowledge based techniques (e.g. identification cards, passwords, PIN etc) This
is because of the ability of biometrics technology to differentiate between an
authorized person and imposter efficiently.
Generally if a vehicle lost and don’t
know who has taken away the vehicle and where it is? In such situation, registering
a complaint in police station and then investigation.. It is totally a risky
and time consuming process and there is no guarantee of finding the vehicle. To
overcome this problem and providing additional security, the proposed
architecture will implement a small technique using GSM and GPS technologies
with an additional future of biometric security.
Vehicle tracking systems are also popular in
consumer vehicles as a theft prevention and retrieval device. Police can simply
follow the signal emitted by the tracking system and locate the stolen vehicle.
When used as a security system, a Vehicle Tracking System may serve as either
an addition to or replacement for a traditional Car alarm. Some vehicle
tracking systems make it possible to control vehicle remotely, including block
doors or engine in case of emergency. The existence of vehicle tracking device
then can be used to reduce the insurance cost.
1.1 Design implementation:
Design
of this system includes Three parts, they are
i.
Interfacing
ii.
Coding
iii.
testing
Here I am using three main modules those
are fingerprint scanner, GPS module, GSM module and I have added vibration
sensor, motor and its driver.
I
assigned individual functionality to the individual modules to the individual
modules. The Fingerprint module will store some person’s fingerprints by
enrolling while the login has made. It will checks for authentication and
compares fingerprints with stored data while login. GPS module will takes the
latitude and longitude values and forwards its values to the controller. GSM
module will communicate with controller and used for messaging by using ATL
commands. Vibration sensor is used to detect accidents. Motor is used to verify
the output. Here we can assume the motor as vehicle engine.
I
interfaced all these modules after knowing their pin functionalities. I wrote
coding by assigning their functionalities. Testing is done by seeing the exact
values of GPS and at exact timings of out puts like fingerprint detection,
motor starting/stopping etc.
1.2 Literature survey:
This dissertation is to protect the vehicle by giving some
advanced features than present system. Here I am giving security through
fingerprint module. For developing this system we need to have the knowledge on
the previous papers.
·
Ganesh, Balaji, Varadhan “Anti-Theft Tracking
System for Automobiles” 2011 IEEE Paper
- Islam,
Karhu, Salonen” GPS and GSM antenna
with a capacitive feed for a personal avigator device”-IEEE Paper 2010
·
Cai-Cong Wu, Xiu-Wan Chen, Hong Li, Zhong-Zhong
Wu, Ying-Chun Tao”Design and development of farm vehicle monitoring and
intelligent dispatching system” 2004 IEEE paper.
·
Qiang Liu; Huapu Lu; Hongliang Zhang; Bo Zou “Research
and Desing of Intelligent Vehicle Monitoring System Based on GPS/GSM” 2006 IEEE
Paper.
- Hindawi, Nader “Performance of
differential GPS based on a real-time algorithm using SMS services of GSM
network” 2012 IEEE Paper.
·
Peng Chen; Shuang Liu “Intelligent Vehicle Monitoring System,
Based on GPS, GSM and GIS” 2010 IEEE
Paper.
1.2.1 Anti-Theft Tracking
System for Automobiles
The working is simple and just
similar to carrying a mobile phone along with you and connecting to it from
another device. Here we vary the working from that of the GPS which connects
through the internet and then a user interface, by just displaying the
information containing the location and other essential details through an SMS.
First, the GSM anti-theft tracking system is put to task when
it receives a message from the user, which is during a vehicle hijack. This
triggers the microcontroller in switching OFF the engine or it stimulates the
module in forwarding the location or both.
1.2.2 GSM and GPS based vehicle
location and tracking system
This dissertation is designed using 8051
microcontroller in this dissertation it is proposed to design an embedded system which is
used for tracking and positioning of any vehicle by using Global Positioning System
(GPS) and Global system for mobile communication (GSM). In this project LPC2148 microcontroller is used for
interfacing to various hardware peripherals. The current design is an embedded
application, which will continuously monitor a moving Vehicle and report the
status of the Vehicle on demand. For doing so an LPC2148 microcontroller is
interfaced serially to a GSM Modem and GPS Receiver. A GSM modem is used to
send the position (Latitude and Longitude) of the vehicle from a remote place.
The GPS modem will continuously give the data i.e. the latitude and longitude indicating the
position of the vehicle. The GPS modem gives many parameters as the output, but
only the NMEA data coming out is read and displayed on to the LCD. The same
data is sent to the mobile at the other end from where the position of the
vehicle is demanded. An EEPROM is used to store the mobile number. The hardware
interfaces to microcontroller are LCD display, GSM modem and GPS Receiver. The
design uses RS-232 protocol for serial communication between the modems and the
microcontroller. A serial driver IC is used for converting TTL voltage levels
to RS-232 voltage levels. In the main they are easy to steal, and the average
motorist has very little knowledge of what it is all about. To avoid this kind
of steal we are going to implement this project which provides more security to
the vehicle. When the request by user is sent to the number at the modem, the
system automatically sends a return reply to that mobile indicating the
position of the vehicle in terms of latitude and longitude from this information
we can track our vehicles.
1.2.3 Combining
GPS and GSM Cell-ID positioning for Proactive Location-based Services
Mobile terminals with built-in GPS
receivers are becoming more and more available, thus the public deployment of
location-based services (LBS) becomes feasible. Upcoming LBS are no longer only
reactive but getting more and more proactive, enabling the users to subscribe
for certain events and get notified when e.g. a friend approaches or a point of
interest comes within proximity. However, power consumption for continuous
tracking is still a major issue with mobile terminals. In this paper we define
this problem and propose solutions for an energy efficient combination of GPS
and GSM Cell-ID positioning for mobile terminals. We introduce several strategies for extending the
lifetime of the battery and show how these strategies can be integrated into
existing middleware solutions. Simulations based on a realistic proactive multi-user
context confirm the approach.
1.2.4 A New
Approach of Automobile Localization System Using GPS and GSM/GPRS Transmission
This paper presents a low cost automotive localization system using GPS and GSM-SMS services. The system permits localization of the automobile
and transmitting the position to the owner on his mobile phone as a short
message (SMS) at his request. The system can be
interconnected with the car alarm system and alert
the owner, on his mobile phone, about the events that occurs with his car when
it is parked. The system is composed by a GPS
receiver, a microcontroller and a GSM phone. Additional, the system can be settled for
acquiring and transmitting of information, when requested, about automobile status and parameters (engine status, speed,
direction, etc.) or alert when it started engine, exceed a given speed limit or
if leave a specific area. By using the PC connection, the system
can be used as navigation system. Optional, the system can be used as car tracking
system if connected with GSM/GPRS phone. The
presented application is a low cost solution for automobile position localizing and status, very useful in
case of car theft situations (alarm alert, engine
starting, localizing), for adolescent drivers
watching and monitoring by their parents (speed limit exceeding, leaving a
specific area), as well as in car tracking system application. The proposed solution can be used in
other types of application, where the information needed are requested rarely
and at irregular period of time (when requested).
1.2.5 Research and
Design of Intelligent Vehicle Monitoring System Based on GPS/GSM
Based on the
principle of the intelligent vehicle
monitoring system using GPS/GSM, this paper analyzed
the key technologies of the system such as GIS, wireless positioning and
communication. Details about the design and
implementation of the system are discussed in this
paper. Such a system provides practical measures to
resolve problems like vehicle hijacking and theft in traffic control and
management. In addition, this system also offers
certain references in monitoring civil vehicles and providing cogent
evidence for vehicle theft cases
1.2.6 Design and
development of farm vehicle monitoring and intelligent dispatching system
More and more large farms adopt precision agriculture technology in
China. On the base of requirement investigation, the paper designed and
developed farm vehicle monitoring and intelligent dispatching system (FVMIDS)
for a large farm, which owns 13,000 hm2 of land and has the most
advanced agricultural mechanism in the world. The principle, technology and
method of GPS, GIS, GSM and operational research were used for system design
and development. The system could meet the following requirements: vehicle
dispatching, vehicle inducing, vehicle monitoring, farming operation analyzing
& statistics, means of production dispatching, and so on. The model of
vehicle dispatching based on "transportation problem" was emphasized
in the paper. Test run shows that the system can meet all the requirements of
the farm and decrease vehicle-dispatching cost largely.
1.2.2 Intelligent Vehicle Monitoring System Based on GPS, GSM and GIS
To meet the requirements of some intelligent vehicle monitoring system,
the software integrates Global Position System (GPS), Geographic Information
System (GIS) and Global System for Mobile communications (GSM) in the whole.
The structure, network topology, functions, main technical features and their
implementation principles of the system are introduced. Then hardware design of
the vehicle terminal is given in short. Communication process and data
transmission between the server and the client (relay server) and client
through TCP/IP and UDP protocol are discussed in detail in this paper. Testing
result using LoadRunner software is also analyzed. Practice shows the
robustness of the software and feasibility of object-oriented programming.
1.2.3 GPS and GSM
antenna with a capacitive feed for a personal navigator device:
In
this paper, the GPS and GSM antenna system with the new capacitive feed for a
personal navigator is proposed. A very simple and effective antenna solution is
introduced, making use of the device back cover in the antenna design. Compact
size and good performance make this antenna an attractive solution for a
personal navigator device. The antenna is capable for wide band GPS and
forur-band GSM coverage.
1.2.4 Required Knowledge for the project Implementation:
·
Embedded
C programming
·
Different
Microcontrollers and specifications.
·
Interfacing
techniques for microcontroller with GSM, GPS, fingerprint, vibration sensor and
motor.
·
Detailed
knowledge on GSM, GPS, fingerprint modules.
·
Knowledge
on Keil, Proteus, Flash magic softwares.
CHAPTER 2
Microcontroller
2.1 Introduction to Microcontroller:
A microprocessor system consists of a
microprocessor with memory, input ports and output ports connected to it
externally. A microcontroller is a single chip containing a microprocessor,
memory, input ports and output ports. Since all four blocks reside on the one
chip, a microcontroller is much faster than a microprocessor system.
We have several other basic
microcontroller families such as PIC, M68HCXX, and AVR etc. All these basic
microcontrollers are useful for implementing basic interfacing and control
mechanisms for simple applications. There are several applications which
require lot of computation and high speed data processing. In such applications
advanced microcontrollers and microprocessors are used. One such advanced
architecture is ARM.
2.2 History of ARM:
ARM
stands for Advanced RISC machine. The first processor in ARM family was
developed at Acorn Computers Ltd between October 1983 and April 1985. Acorn
Computers was a British computer company established in Cambridge, England, in
1978. The company worked for Reduced Instruction Set Computer (RISC) processor
design. The company produced a variety of computers which were very popular in
the United Kingdom. These included the Acorn Electron, the BBC Micro and the
Acorn Archimedes. Particularly BBC Micro computer dominated the UK educational
computer market during the 1980s and early 1990s.
2.3
ARM Architecture:
The ARM core
uses RISC architecture. Its design philosophy is aimed at delivering simple but
powerful instructions that execute within a single cycle at a high clock speed.
The RISC philosophy concentrates on reducing the complexity of instructions
performed by the hardware because it is easier to provide greater flexibility
and intelligence in software rather than hardware. As, a result RISC design
plays greater demands on the compiler. In contrast, the traditional complex
instruction set computer (CISC) relies more on the hardware for instruction
functionality, AND consequently the CISC instructions are more complicated. Certain
design features have been characteristic of most RISC processors:
One cycle execution time: RISC processors have a CPI (clock per
instruction) of one cycle. This is due to the optimization of each instruction
on the CPU. Each instruction is of a fixed length to allow the pipeline to
fetch future instructions before decoding the current instruction.
Pipelining: The processing
of instructions is broken down into smaller units that can be executed in
parallel by pipelines. Ideally the pipeline advances by one step on each cycle
for maximum throughput. Instructions can be decoded in one pipeline stage.
Large number of registers: The RISC design philosophy generally
incorporates a larger number of registers to prevent large amount of
interactions with memory. Any register can contain either data or an address.
Registers act as the fast local memory store for all data processing operation.
Load-store architecture: The processor
operates on data held in registers. Separate load and store instructions
transfer data between the register bank and external memory
These design rules allow a RISC
processor to be simpler, and thus the core can operate at higher clock
frequencies.
2.4
ARM Processor Core:
Similar to most RISC machines
ARM works on load-store architecture, so only load and store instructions
perform memory operations and all other arithmetic and logical operations are
only performed on processor registers. The figure shows the ARM core data flow
model. In which the ARM core as functional units connected by data buses,. And
the arrows represent the flow of data, the lines represent the buses, and boxes
represent either an operation unit or a storage area. The figure shows not only
the flow of data but also the abstract components that make up an ARM core.
In the
above figure the Data enters the
processor core through the Data bus. The data may be an instruction to execute
or a data item. This ARM core represents the Von Neumann implementation of the ARM data items and instructions
share the same bus. In contrast, Harvard implementations of the ARM use two
different buses.
The instruction decoder translates
instructions before they are executed. Each instruction executed belongs to a
particular instruction set.
The ARM
processors, like all RISC processors, use load-store architecture. This means it has two instruction types for
transferring data in and out of the processor: load instructions copy data from
memory to registers in the core, and conversely the store instructions copy
data from registers to memory. There are no data processing instructions that
directly manipulate data in memory. Thus, data processing is carried out solely
in registers.
Data
items are placed in the register file – a storage bank made up of 32-bit
registers. Since the ARM core is a 32- bit processor, most instructions treat
the registers as holding signed or unsigned 32-bit values. The sign extend hardware converts signed
8-bit and 16-bit numbers to 32-bit values as they are read from memory and
placed in a register.
The ALU
(arithmetic logic unit) or MAC (multiply – accumulate unit) takes the register
values Rn and Rm from the A and B buses and
computes a result. Data processing instructions write the result in Rd directly to the register file.
Load and store instructions use the ALU to generate an address to be held in
the address register and broadcast on the Address bus.
One
important feature of the ARM is that register Rm alternatively can be preprocessed in the barrel shifter
before it enters the ALU. Together the barrel shifter and ALU can calculate a
wide range of expressions and addresses.
After
passing through the functional units, the result in Rd is written back to the register file using the Result bus. For load and store
instructions the incrementer updates the address register before the core reads
or writes the next register value from or to the next sequential memory
location. The processor continues executing instructions until an exception or
interrupt changes the normal execution flow.
2.4.1
ARM Bus Technology:
Embedded
systems use different bus technologies. The Peripheral Component Interconnect
(PCI) bus connects devices such as video card and disk controllers to the X 86
processor buses. This is called External or off chip bus technology.
Embedded
devices use an on-chip bus that is internal to the chip and allows different
peripheral devices to be inter-connected with an ARM core.
There
are two different types of devices connected to the bus
1.
Bus
Master
2.
Bus
Slave
Bus Master: A logical device capable of
initiating a data transfer with another device across the same bus (ARM
processor core is a bus Master).
Bus Slave: A logical device capable only of
responding to a transfer request from a bus master device (Peripherals are bus
slaves)
Generally
a Bus has two architecture levels
Physical
lever: Which covers electrical characteristics a bus width (16, 32, 64
bus).
Protocol
level: which deals with
protocol?
NOTE: -
ARM is primarily a design company. It seldom implements the electrical
characteristics of the bus, but it routinely specifies the bus protocol
2.4.2
AMBA (Advanced Microcontroller Bus Architecture) Bus protocol:
AMBA Bus
was introduced in 1996 and has been widely adopted as the On Chip bus architecture
used for ARM processors.
The
first AMBA buses were
1.
ARM
System Bus ( ASB )
2.
ARM
Peripheral Bus ( APB )
Later
ARM introduced another bus design called the ARM High performance Bus (AHB).
Using AMBA
i.
Peripheral
designers can reuse the same design on multiple projects
ii.
A
Peripheral can simply be bolted on the On Chip bus with out having to redesign
an interface for different processor architecture.
This plug-and-play interface for
hardware developers improves availability and time to market.
AHB
provides higher data throughput than ASB because it is based on centralized
multiplexed bus scheme rather than the ASB bidirectional bus design. This
change allows the AHB bus to run at widths of 64 bits and 128 bits
ARM
introduced two variations on the AHB bus
1.
Multi-layer
AHB
2.
AHB-Lite
In
contrast to the original AHB , which allows a single bus master to be active on
the bus at any time , the Multi-layer AHB bus allows multiple active bus
masters.
AHB-Lite
is a subset of the AHB bus and it is limited to a single bus master. This bus
was developed for designs that do not require the full features of the standard
AHB bus.
AHB and Multiple-layer AHB support
the same protocol for master and slave but have different interconnects. The
new interconnects in Multi-layer AHB are good for systems with multiple
processors. They permit operations to occur in parallel and allow for higher
throughput rates.
2.4.3 ARCHITECTURE Revisions:
Every ARM processor
implementation executes a specific
instruction set architecture (ISA), although an ISA revision may have
more than one processor implementation .The ISA has evolved to keep up with the
demands of the embedded market. This evolution has been carefully managed by
ARM, so that code written to execute on an earlier architecture revision will
also execute on a later revision of the architecture. The nomenclature
identifies individual processors and provides basic information about the
feature set.
2.4.4
NOMENCLATURE:
ARM uses the nomenclature shown
below is to describe the processor implementations. The letters and numbers
after the word “ARM” indicate the features a processor may have.
ARM { x }{ y }{ z }{ T }{ D }{ M }{ I }{ E }{J
}{ F }{ -S }
x → family
y → memory management / protection unit
z → cache
T → Thumb 16 bit decoder
D → JTAG debug
M → fast multiplier
I → Embedded ICE macro cell
E → enhanced instruction (assumes TDMI)
J → Jazelle
F → vector floating-point unit
S → synthesizable version
Ø All ARM cores after the
ARM7TDMI include the TDMI features even though they may not include those
letters after the “ ARM ” label
Ø The processor family is a group
of processor implementations that share the same hardware characteristics. For
example, the ARM7TDMI, ARM740T, and ARM720T all share the same family
characteristics and belong to the ARM7 family
Ø JTAG
is described by IEEE 1149.1
standard Test Access Port and boundary scan architecture. It is a serial
protocol used by ARM to send and receive debug information between the
processor core and test equipment
Ø Embedded
ICE macro cell is
the debug hardware built into the processor that allows breakpoints and watch
points to be set
Ø Synthesizable means that the processor core
is supplied as source code that can be compiled into a form easily used by
EDA tools.
2.4.5 Introduction to ARM7TDMI core:
The ARM7TDMI
core is a 32-bit embedded RISC processor delivered as a hard macro cell
optimized to provide the best combination of performance, power and area
characteristics.
2.4.6 ARM7TDMI Features:
1)
32/16-bit RISC architecture (ARM v4T)
2)
32-bit ARM instruction set for maximum performance and
flexibility
3)
16-bit Thumb instruction set for increased code density
4)
Unified bus interface, 32-bit data bus carries both
instructions and data
5)
Three-stage pipeline
6)
32-bit ALU
7)
Very small die size and low power consumption
8)
Fully static operation
9)
Coprocessor interface
10) Extensive
debug facilities (Embedded ICE debug unit accessible via JTAG interface unit)
2.4.7 Benefits:
1)
Generic layout can be ported to specific process
technologies
2)
Unified memory bus simplifies SoC integration process
3)
ARM and Thumb instructions sets can be mixed with
minimal overhead to support application requirements for speed and code density
4)
Code written for ARM7TDMI-S is binary-compatible with
other members of the ARM7 Family and forwards compatible with ARM9, ARM9E and
ARM10 families, thus it's quite easy to port your design to higher level
microcontroller or microprocessor
5)
Static design and lower power consumption are essential
for battery -powered devices
6)
Instruction set can be extended for specific
requirements using coprocessors
7) Embedded
ICE-RT and optional ETM units enable extensive, real-time debug facilities
2.5 ARM Register file & modes of operation:
The ARM
architecture has register file with 37 registers. In addition to these
registers there will be several other registers inside the processor which will
not be visible to the programmer but used by the processor internally to execute
instructions. The current program status register (CPSR) has condition flags
and several other control bits. When the ARM enters in privileged modes it has
access to some special registers as explained below.
However
these are arranged into several banks, with the accessible bank being governed
by the processor mode. Each mode can access a particular set of r0-r12
registers, a particular r13 (the stack pointer) and r14 (link register), r15 (the program counter), cpsr (the current program status register)and privileged modes can also
access a particular spsr (saved program status register).In user mode 16 data registers and 2 status registers are visible. Depending
upon context, register r13
and r14 can also be used as General Purpose Registers. In ARM state the
registers r0 to r13 are Orthogonal that means - any instruction which use r0
can as well be used with any other General Purpose Register (r1-r13) .
1)
The ARM processor has
three registers assigned to a particular task or special function: r13, r14 and
r15. They are frequently given different labels to differentiate them from the
other registers.
2)
Register r13 is traditionally used as the
stack pointer (sp) and stores
the head of the stack in the current processor mode
3)
Register r14 is called the link register (lr) and is where the core puts the
return address whenever it calls a subroutine.
4)
Register r15 is the program counter ( pc ) and contains the address of the
next instruction to be fetched by the processor
5)
The register file
contains all the registers available to a programmer. Which registers are
visible to the programmer depend upon the current mode of the processor.
2.5.1
ARM Modes of Operation:
ARM has total seven modes of operation. They are user
, abort, fast interrupt, request, interrupt request, supervisor, system and
undefined. Out of all these modes the user mode is non-privileged mode which
does not have write permissions to CPSR. The other six modes are privileged
modes.
Privileged: -
Full read-write access to the CPSR. Under this we are having Abort,
Fast interrupt request, Interrupt request, Supervisor, System and Undefined.
Abort (10111): When there is a failed
attempt to access memory
Fast interrupt Request (FIQ (10001))
& interrupt request (10010) :
Correspond to interrupt levels available on ARM
Supervisor mode (10011): State after
reset and generally the mode in which OS kernel executes
System mode (11111): Special version of
user mode that allows full read-write access of CPSR.
Undefined (11011): When processor
encounters an undefined instruction
Non-privileged:- Only read access to the
control filed of CPSR but read-write access to the condition flags.
User
(10000): User mode is user for programs and applications. And this is the
normal mode
The above figure shows all 37 registers of register file. Out
of these 37 registers, 20 registers are hidden from a program in different
modes. These are called banked registers
2.5.2
Current program status registers:
The CPSR
is a 32 bit register in addition to the 16 general purpose registers. The CPSR
has flag and control bits in it. The following figure illustrates the bit
positions of various control or flag bits of CPSR.
The CPSR
is divided into 4 fields, each of 8 bits size. They are Flag, status, extension
and control fields. In the present versions of ARM the status and extensions
field’s bits are reserved for future use.
If flag
up date option is enabled1 then the flag bits will be changed as
described below. Remember that flag bits are only affected when such option is
chosen in the instruction; otherwise flag bits will preserve their old values.
N –
Negative flag; this bit is set when the 31 bit (most significant bit) of result
is one, otherwise it is reset
Z – Zero
flag; this bit set if the result is zero, otherwise it is reset
C –
carry flag; this bit is set when there is a carry out of addition and no barrow
for subtraction, otherwise it is reset
V –
overflow flag; this bit is set when there is overflow in signed arithmetic
operations
The I
and F bits correspond to interrupt masking and the T bit tells the thumb state
(whether the processor is in normal mode or thumb mode).
The least significant five bits of CPSR indicate the mode in
which processor is currently operating. Except in user mode in all other modes
it is possible to write appropriate value in these bits for changing to any
other mode. The mode also can be changed when exception or interrupt occurs.
The following exceptions and interrupts results in mode change: reset, interrupt request, and fast interrupt
request, software interrupt, data abort,
pre-fetch abort and execution
of undefined instruction.
2.5.3
Banked registers:
Out of total 37 registers in register file at any
time the processor accesses 17 registers, remaining 20 registers are called
banked registers. If the processor is in user mode it accesses all R0 to R15
and CPSR register which are shown in first column in above diagram. Banked
registers are available only
when the processor is in a particular mode. Processor modes (other than
system mode) have a set
of associated banked registers that are subset of 16 register.
Consider if the processor is in fast interrupt request
mode then the register R8_fiq is used instead of R8 and similarly for few other
registers as shown in above figure. So the original R8 register is unchanged
when the processor comes back to the user mode.
2.5.4
SPSR:
The saved program status registers (SPSR)
stores the previous mode’s CPSR when there is a mode change. When the processor
returns by using special return instruction the CPSR is restored from the
corresponding SPSR. Each privileged mode (except system mode) has associated with it a
Save Program Status Register, or SPSR.
Mode Changing:
Mode changes by writing
directly to CPSR or by hardware when the
processor responds to exception or interrupt.
To return to user mode a
special return instruction is used that instructs the core to restore
the original CPSR and banked registers.
2.6 ARM Instruction Set:
Different ARM architectures
revisions support different instructions. However new revisions usually add
instructions and remain backwardly compatible. The following shows the type of
instructions that ARM support.
I.
Data Processing Instructions
II.
Branch Instructions
III.
Load-store Instructions
IV.
Software Interrupt Instruction
V.
Program Status Register Instructions
LPC2148
MICROCONTROLLER
While the USB DMA is the primary user of the additional 8 kB
RAM, this RAM is also accessible at any time by the CPU as a general purpose
RAM for data and code storage.
2.5
Pinning information
4.5
IR-SENSOR
4.7.6
Architecture of the GSM network:
4.7.6.3 Network Subsystem
4.8.1 LCD operation:
4.10.1 A Typical Application
4.12.1
Basic Theory
CHAPTER 3
LPC2148
MICROCONTROLLER
3.3.1 General description
The LPC2141/42/44/46/48 microcontrollers are
based on a 16-bit/32-bit ARM7TDMI-S CPU with real-time emulation and embedded
trace support, that combine the microcontroller with embedded high-speed flash
memory ranging from 32 kB to 512 kB. A 128-bit wide memory interface and a
unique accelerator architecture enable 32-bit code execution at the maximum
clock rate. For critical code size applications, the alternative 16-bit Thumb
mode reduces code by more than 30 % with minimal performance penalty. Due to
their tiny size and low power consumption, LPC2141/42/44/46/48 are ideal for
applications where miniaturization is a key requirement, such as access control
and point-of-sale. Serial communications interfaces ranging from a USB 2.0
Full-speed device, multiple UARTs, SPI, SSP to I2C-bus and on-chip SRAM of 8 kB
up to 40 kB, make these devices very well suited for communication gateways and
protocol converters, soft modems, voice recognition and low end imaging,
providing both large buffer size and high processing power. Various 32-bit
timers, single or dual 10-bit ADC(s), 10-bit DAC, PWM channels and 45 fast GPIO
lines with up to nine edge or level sensitive external interrupt pins make
these microcontrollers suitable for industrial control and medical systems.
2.3.2 Features and benefits
2.3.2.1 Key features
·
16-bit/32-bit ARM7TDMI-S microcontroller in a tiny LQFP64 package.
·
8 kB to 40 kB of on-chip static RAM and 32 kB to 512 kB of on-chip
flash memory.
·
128-bit wide interface/accelerator enables high-speed 60 MHz
operation.
·
In-System Programming/In-Application Programming (ISP/IAP) via
on-chip boot
loader software. Single
flash sector or full chip erase in 400 ms and programming of
256 B in 1 ms.
·
EmbeddedICE RT and Embedded Trace interfaces offer real-time
debugging with the
on-chip RealMonitor
software and high-speed tracing of instruction execution.
·
USB 2.0 Full-speed compliant device controller with 2 kB of
endpoint RAM.In addition, the LPC2146/48 provides 8 kB of on-chip RAM
accessible to USB by DMA.
·
One or two (LPC2141/42 vs. LPC2144/46/48) 10-bit ADCs provide a
total of 6/14 analog inputs, with conversion times as low as 2.44 s per
channel.
·
Single 10-bit DAC provides variable analog output
(LPC2142/44/46/48 only).
·
Two 32-bit timers/external event counters (with four capture and
four compare channels each), PWM unit (six outputs) and watchdog.
·
Low power Real-Time Clock (RTC) with independent power and 32 kHz
clock input.
·
Multiple serial
interfaces including two UARTs (16C550), two Fast I2C-bus (400 kbit/s),
SPI and SSP with buffering and variable data length capabilities.
·
Vectored Interrupt
Controller (VIC) with configurable priorities and vector addresses.
·
Up to 45 of 5 V tolerant
fast general purpose I/O pins in a tiny LQFP64 package.
·
Up to 21 external
interrupt pins available.
·
60 MHz maximum CPU clock
available from programmable on-chip PLL with settling
time of 100 s.
·
On-chip integrated
oscillator operates with an external crystal from 1 MHz to 25 MHz.
·
Power saving modes
include Idle and Power-down.
·
Individual
enable/disable of peripheral functions as well as peripheral clock scaling for
additional power optimization.
·
Processor wake-up from
Power-down mode via external interrupt or BOD.
·
Single power supply chip
with POR and BOD circuits:
·
CPU operating voltage
range of 3.0 V to 3.6 V (3.3 V 10 %) with 5 V tolerant I/O pads.
2.5
Pinning information
3.6 Functional description
3.6.1 Architectural overview
The
ARM7TDMI-S is a general purpose 32-bit microprocessor, which offers high
performance and very low power consumption. The ARM architecture is based on
Reduced Instruction Set Computer (RISC) principles, and the instruction set and
related decode mechanism are much simpler than those of microprogrammed Complex Instruction Set
Computers (CISC). This simplicity results in a high instruction throughput and
impressive real-time interrupt response from a small and cost-effective
processor core.
Pipeline techniques are employed so that all
parts of the processing and memory systems can operate continuously. Typically,
while one instruction is being executed, its successor is being decoded, and a
third instruction is being fetched from memory. The ARM7TDMI-S processor also
employs a unique architectural strategy
known as Thumb, which makes it ideally suited to high-volume applications with
memory restrictions, or applications where code density is an issue. The key
idea behind Thumb is that of a super-reduced instruction set. Essentially, the
ARM7TDMI-S processor has two instruction sets:
• The standard 32-bit ARM
set.
• A 16-bit Thumb set.
The Thumb set’s 16-bit instruction length
allows it to approach twice the density of standard ARM code while retaining
most of the ARM’s performance advantage over a traditional 16-bit processor
using 16-bit registers. This is possible because Thumb code operates on the
same 32-bit register set as ARM code.
Thumb
code is able to provide up to 65 % of the code size of ARM, and 160 % of the
performance of an equivalent ARM processor connected to a 16-bit memory system.
The particular flash implementation in the LPC2141/42/44/46/48 allows for full
speed execution also in ARM mode. It is recommended to program performance critical and short code
sections (such as interrupt service routines and DSP algorithms) in ARM mode.
The impact on the overall code size will be minimal but the speed can be
increased by 30 % over Thumb mode.
3.6.2 On-chip flash program memory
The
LPC2141/42/44/46/48 incorporate a 32 kB, 64 kB, 128 kB, 256 kB and 512 kB flash
memory system respectively. This memory may be used for both code and data
storage. Programming of the flash memory may be accomplished in several ways.
It may be programmed In System via the serial port. The application program may
also erase and/or program the flash while the application is running, allowing a
great degree of flexibility for data storage field firmware upgrades, etc. Due
to the architectural solution chosen for an on-chip boot loader, flash memory
available for user’s code on LPC2141/42/44/46/48 is 32 kB, 64 kB, 128 kB, 256
kB and 500 kB respectively. The LPC2141/42/44/46/48 flash memory provides a
minimum of 100000 erase/write cycles and 20 years of data-retention.
3.6.3 On-chip static RAM
On-chip static RAM may be used for code and/or data storage. The SRAM
may be accessed as 8-bit, 16-bit, and 32-bit. The LPC2141, LPC2142/44 and
LPC2146/48 provide 8 kB, 16 kB and 32 kB of static RAM respectively. In case of
LPC2146/48 only, an 8 kB SRAM block intended to be utilized mainly by the USB
can also be used as a general purpose RAM for data storage and code storage and
execution.
3.6.4 Memory map
The
LPC2141/42/44/46/48 memory map incorporates several distinct regions,In
addition, the CPU interrupt vectors may be remapped to allow them to reside in
either flash memory (the default) or on-chip static RAM.
3.6.5 Interrupt controller
3.6.10.1 Features
3.6.12.1 Features
3.6.16.1 Features
3.6.18 Pulse width modulator
CHAPTER 4
An ignition switch plays the key role
in the vehicle, for moving. If it is in
off condition, the vehicle does not move at an inch. In this project, for completely stopping the
vehicle we are just switched-off the ignition switch with the help of the micro
controller. A LCD display is used at the output section. To display the status of the GSM and
GPS. The maximum power supply required
to operate the hardware circuitry is +5V DC voltage. An IR transmitter and an
IR receiver is used to activate the fingerprint module and to give user ID. An
enrolling switch is used to allow authorization to the other persons while the
authorized person is logged in through fingerprint module.
4.3 Hardware components required:
A list of some of the strengths,
weaknesses and suitable applications for each biometric methodology a list of
some of the strengths, weaknesses and suitable applications for each biometric
methodology.
1)
Authentication – the
process of verifying that a user requesting a network resource is who he, she,
or it claims to be, and vice versa.
2) Conventional authentication methods
4.4.8
Pattern Recognition:
1) Description and classification of
measurements taken from physical or mental processes
4.4.10 Advantages:
Major technical indicators
1)
Supply
voltage: 5V
1
1
VCC in 5V power input (input supply voltage range can be 3.6 ~ 7.5V)
2
TXD
out the serial port transmitter
POWER-ON DELAY TIME
An ignition switch plays the key role
in the vehicle, for moving. If it is in
off condition, the vehicle does not move at an inch. In this project, for completely stopping the
vehicle we are just switched-off the ignition switch with the help of the micro
controller. A LCD display is used at the output section. To display the status of the GSM and
GPS. The maximum power supply required
to operate the hardware circuitry is +5V DC voltage. An IR transmitter and an
IR receiver is used to activate the fingerprint module and to give user ID. An
enrolling switch is used to allow authorization to the other persons while the
authorized person is logged in through fingerprint module.
4.2 Block diagram:
4.3 Hardware components required:
For the implementation
of fingerprint protected anti theft tracking system we required some important
components. Those are:
1.
Fingerprint module
2.
LPC2148 Microcontroller(consists
ARM7TDMI-S processor)
3.
GPS module
4.
GSM module
5.
Switches
6.
Vibration sensor
7.
Motor and its driving circuit
8.
230/18V step down transformer
9.
Bridge rectifier
4.4 Fingerprint module:
A fingerprint sensor is an electronic device used to capture a digital image of the fingerprint pattern. The captured image is called a
live scan. This live scan is digitally
processed to create
a biometric template (a collection of extracted features) which is stored and used for
matching.
4.4.1
General Descriptions:
FIM30 is an evolutionary standalone
fingerprint recognition module consisted of optic sensor and processing board.
As CPU and highly upgraded algorithm are embedded into a module, it provides
high recognition ratio even to small size, wet, dry, calloused fingerprint.
High speed 1: N identification and 1: N verification.
Fingerprint processing consisting of
two process: fingerprint logon process and the fingerprint matching process [which
is divided into fingerprint matching fingerprint matcing [1:1] and fingerprint
search (1:N) in two ways].
Fingerprint login, fingerprint entry
for each one 2times e times the input of image processing, synthetic templates
stored I the module. Fingerprint match, the first through the fingerprint
sensor to verify the fingerprint image input and processing, and then with the
module to match the fingerprint template comparison (If specified in the module
to match a template, called the fingerprint matching method, namely, 1:N mode),
the module gives the matching results (pass or fail.)
4.4.2
Key Function:
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. The following timing diagram and table show the operation condition
of keys. FIM 30 has functions of fingerprint enrollment, identification,
partial and entire deletion and reset in a single board, it does not require
connection with a separate PC, thereby offering convenient development
environment. Off-line functionality
stores logs on the equipment memory (up to 100 fingerprints) and it’s
identified using search engine from the internal algorithm. Evolutionary standalone fingerprint
recognition module FIM30 is ideal for on-line applications, because allows
ASCII commands to manage the device from the host. On-line functionality, fingerprints to verify
(1:1) or identify (1: N) can be stored on non volatile memory, or be sent by
RS-232 port. This FIM 3030 is going to
have the Optical Sensor to Enroll and Identify the Finger Print.
4.4.3 Optical sensor:
Optical fingerprint imaging involves
capturing a digital image of the print using visible light. This type of sensor is, in essence, a specialized digital camera. The top layer of the sensor, where the finger is placed, is
known as the touch surface. Beneath this layer is a light-emitting phosphor
layer which illuminates the surface of the finger. The light reflected from the
finger passes through the phosphor layer to an array of solid state pixels (a charge-coupled
device) which
captures a visual image of the fingerprint. A scratched or dirty touch surface
can cause a bad image of the fingerprint. A disadvantage of this type of sensor
is the fact that the imaging capabilities are affected by the quality of skin
on the finger. For instance, a dirty or marked finger is difficult to image
properly. Also, it is possible for an individual to erode the outer layer of
skin on the fingertips to the point where the fingerprint is no longer visible.
It can also be easily fooled by an image of a fingerprint if not coupled with a
"live finger" detector. However, unlike capacitive sensors, this
sensor technology is not susceptible to electrostatic discharge damage.
4.4.4
Why go for Biometrics?
A list of some of the strengths,
weaknesses and suitable applications for each biometric methodology a list of
some of the strengths, weaknesses and suitable applications for each biometric
methodology.
2) Conventional authentication methods
a) something that you have – key, magnetic
card or smartcard
b)
something that
you know – PIN or password
3)
Biometric
authentication uses personal features
a)
something that you are
4.4.5 Advantages:
Biometrics has no risk of
1)
Forgetting
it
2)
Loosing
it
3)
Getting
it stolen
4)
Getting
it copied
5)
Being
used by anyone else.
4.4.6
Essential Properties of a Biometric:
1)
Universal
a) Everyone should have the
characteristic
2)
Uniqueness
a) No two persons have the same
characteristic
3)
Permanence
a) Characteristic should be unchangeable
4)
Collectability
a) Characteristic must be measurable
4.4.7
Biometric System Process Flow:
1) Description and classification of
measurements taken from physical or mental processes
2) Examination of pattern
characteristics
3) Formulation of the recognition system
4) Important part of any biometric
system
4.4.9
Why Fingerprint biometry?
1)
High Universality
a) A majority of the population
(>96%) have legible fingerprints
b) More than the number of people who
possess passports, license and IDs
2)
High Distinctiveness
a) Even identical twins have different
fingerprints (most biometrics fail)
b) Individuality of fingerprints
established through empirical evidence
3)
High Permanence
a) Fingerprints are formed in the fetal
stage and remain structurally unchanged through out life.
b) One of the most accurate forms of
biometrics available
c) Best trade off between convenience
and security
4)
High Acceptability
a) Fingerprint acquisition is non
intrusive. Requires no training.
4.4.10 Advantages:
1) Uniqueness
2) Surety over the Cards and Keypads
3) Against to Cards Duplication,
misplacement and improper disclosure of password
4) No excuses for RF/Magnetic Cards
forget ness
5) No need to further invest on the
Cards Cost
6) No need to further manage the Cards
Writing Devices
4.4.11
Fingerprint Patterns
1) Loops
a) Ridge lines enter from one side and
curve around to exit from the same side
b) 60-65% of population
2) Whorls
a) Rounded or circular ridge pattern
b) 30-35% of population
3) Arches
a) Ridge lines enter from one side of
print and exit out the other
b) 5% of population
1)
Supply
voltage: 5V
2)
Supply
current:
3)
Current:
100mA
4)
Peak
current: 150mA
5)
Fingerprint
image input time: <0.5 second window area 14”18mm
6)
Matching:
7)
Comparison
method(1:1)
8)
Search
mode(1:N) profile:256 bytes
9)
Template
file: 512 bytes
10)
Storage
capacity: 900
11)
Security
level: five(from low to high: 1,2,3,4,5)
12)
False
Accept Rate (FAR):<0.001%(safety class3)
13)
False
rejection rate(FRR): <0.1% (safety class3)
14)
Search
time:<1.0 seconds (1:1000, the mean value)
15)
PC
interface: UART (TTL logic level) or USB1.1
16)
Communications
baud rate (UART): (9600*N)bps where N=1~12(default N=6, ie 57600bps)
17)
Storage
environment:
18)
Temperature:
-40 C - +85C
2
TXD
out the serial port transmitter
3
RXD
in serial port receiver
4
GND
– system ground
5
KEYPOWER
– power IC’s power supply should be input, input voltage is 5V (input supply
voltage range can be 3.6 ~ 7.5V)
6
OUT
– output of the power sensor, usually high output of 3.3V, when a finger
touches the sensing area, this pin outputs low.
4.4.12 Serial protocol:
Halfn – duplex asynchronous serial communication recognize wave. Olmert
was 57600bos, set by command 9600 ~ 115200bps
Frame format is 10 bits, a 0-level
start bit, 8 data bits (LSB first) and a
stop bit, no parity
POWER-ON DELAY TIME
Power
module, the initialization time is about 500mS. During this period, the module
can not respond to the host computer command.
4.4.13 Fingerprint Database:
Opened in the
FLASH module I a fingerprint template storage area as a storage area, commonly
known as the fingerprint database.
Fingerprint library data is power protection. Fingerprint template stored in
accordance with the serial nuber, if the fingerprint storage capacity of N, the
fingerprint template in the fingerprint library number is defined
as:0,1,2,…..N-2,N-1. Users can only access the fingerprint database based on
the content of serial number.
4.5
IR-SENSOR
Infrared (IR)
radiation is part of the electromagnetic spectrum, which includes radio waves,
microwaves, visible light, and ultraviolet light, as well as gamma rays and
X-rays. The IR range falls between the visible portion of the spectrum and
radio waves. IR wavelengths are usually expressed in microns, with the lR
spectrum extending from 0.7 to
1000microns. Using advanced optic systems and detectors, non-contact IR
thermometers can focus on nearly any portion or portions of the 0.7-14 micron
band. Because every object (with the exception of a blackbody) emits an optimum
amount of IR energy at a specific point along the IR band, each process may
require unique sensor models with specific optics and detector types. For
example, a sensor with a narrow spectral range center data 3.43 microns is optimized
for measuring the surface temperature of polyethylene and related materials. A
sensor set up for 5 microns is used to measure glass surfaces. A micron sensor
is used for metals and foils. The broader spectral ranges are used to measure
lower temperature surfaces, such as paper, board, poly, and foil composites.
The intensity of
an object's emitted IR energy increases or decreases in proportion to its
temperature. It is the emitted energy, measured as the target's emissivity that
indicates an object's temperature. Emissivity is a term used to quantify the
energy-emitting characteristics of different materials and surfaces. IR sensors
have adjustable emissivity settings, usually from 0.1 to 1.0, which allow
accurate temperature measurements of several surface types. The emitted energy
comes from an object and reaches the IR sensor through its optical system,
which focuses the energy onto one or more photosensitive
detectors. The detector then converts the IR energy into an electrical signal,
which is in turn converted into a temperature value. Based on the sensor's
calibration equation and the target's emissivity. This temperature value can be
displayed on the sensor or, in the case of the smart sensor, converted to a
digital output and displayed on a computer terminal. IR remote
controls use wavelengths between 850 - 950nm. At this short wavelength, the
light is invisible to the human eye, but a domestic camcorder can actually view
this portion of the electromagnetic spectrum. Viewed with a camcorder, an IR
LED appears to change brightness.
All remote controls use an encoded
series of pulses, of which there are thousands of combinations. The light
output intensity varies with each remote control, remotes working at 4.5V dc
generally will provide a stronger light output than a 3V dc control. Also, as
the photodiode in this project has a peak light response at 850nm, it will
receive a stronger signal from controls operating closer to this
wavelength. The photodiode will actually respond to IR wavelengths from 400nm
to 1100nm,so all remote controls should be compatible.
- the sensor should be sensitive to the measured
property
- the sensor should be insensitive to any other
property
- the sensor should not influence the measured
property
In theory, when the sensor is working
perfectly, the output signal of a sensor is exactly proportional to the value
of the property it is meant to measure. The gain is then defined as the ratio
between output signal and measured property. For example, if a sensor measures
temperature and has an actual voltage output, the gain is a constant with the
unit.
When the sensor is not perfect,
various deviations can occur, including gain error, long term drift, and noise.
These and other deviations can be classified as systematic, or random, errors.
Systematic deviations may be compensated for by means of some kind of
calibration strategy. Noise is an example of a random error that can be reduced
by signal processing, such as filtering, usually at the expense of the dynamic
behavior of the sensor.
4.5.1 Advantages:
Due
to their resistance to ambient-light impediments and electromagnetic
interference (EMI), Infrared LEDs enhance the performance of wireless
computer-to-PDA links, collision avoidance systems, automation equipment,
biomedical instrumentation, and telecommunications equipment.
4.5.3
Suitable Data Format
The circuit of the TSOP17 is designed in that way that
unexpected output pulses due to noise or disturbance signals are avoided. A
bandpass filter, an integrator stage and an automatic gain control are used to
suppress such disturbances. The distinguishing mark between data signal and
disturbance signal are carrier frequency, burst length and duty cycle. The data
signal should fulfill the following condition• Carrier frequency should be
close to center frequency of the band pass (e.g. 38 kHz). Burst length should
be 10 cycles/burst or longer. • After each burst which is between 10 cycles and
70cycles a gap time of at least 14 cycles is necessary. For each burst, which is longer than 1.8ms, a
corresponding gap time is necessary at some time in the data stream. This gap
time should have at least same length as the burst. • Up to 1400 short bursts
per second can be received continuously. Some examples for suitable data format
are: NEC Code, Toshiba Micom Format, Sharp Code, RC5 Code, RC6 Code, R–2000
Code, Sony Format (SIRCS).When a disturbance signal is applied to the TSOP17. it
can still receive the data signal. However the sensitivity is reduced to that
level that no unexpected pulses will occur. Some examples for such disturbance
signals which are suppressed by the TSOP17are:
- Know precisely
how far you have run and at what pace while tracking your path so you can
find your way home.
- Pinpoint the perfect
fishing spot on the water and easily relocate it.
- Get the closest
location of your favorite restaurant when you are out-of-town.
- Find the
nearest airport or identify the type of airspace in which you are flying
4.6.2 What is GPS?
Control Segment
The
control segment is responsible for constantly monitoring satellite health,
signal integrity, and orbital configuration from the ground control segment
includes the following sections:
The
signals are so accurate that time can be figured to much less than a millionth
of a second, velocity can be figured to within a fraction of a mile per hour,
and location can be figured to within a few meters.
WAAS/EGNOS:
Price:
4.7 GLOBAL SYSTEM FOR MOBILE COMMUNICATION
4.7.1Definition:
GSM Modem:
A GSM modem can be an external modem device, such as the Wavecom FASTRACK
Modem. Insert a GSM SIM card into this
modem, and connect the modem to an available serial port on your computer.
A GSM modem can be a PC Card installed in a notebook computer, such as
the Nokia Card Phone.
A GSM modem could also be a standard GSM mobile phone with the
appropriate cable and software driver to connect to a serial port on your
computer. Phones such as the Nokia 7110
with a DLR-3 cable, or various Ericsson phones, are often used for this
purpose.
A dedicated GSM modem (external or PC Card) is usually preferable to a
GSM mobile phone. This is because of some
compatibility issues that can exist with mobile phones. For example, if you wish to be able to
receive inbound MMS messages with your gateway, and you are using a mobile
phone as your modem, you must utilize a mobile phone that does not support WAP
push or MMS. This is because the mobile
phone automatically processes these messages, without forwarding them via the
modem interface. Similarly some mobile
phones will not allow you to correctly receive SMS text messages longer than
160 bytes (known as “concatenated SMS” or “long SMS”). This is because these long messages are
actually sent as separate SMS messages, and the phone attempts to reassemble
the message before forwarding via the modem interface. (We’ve observed this latter problem utilizing
the Ericsson R380, while it does not appear to be a problem with many other
Ericsson models.)
When you install your GSM modem, or connect your GSM mobile phone to the
computer, be sure to install the appropriate Windows modem driver from the
device manufacturer. To simplify
configuration, the Now SMS/MMS Gateway will communicate with the device via
this driver. An additional benefit of
utilizing this driver is that you can use Windows diagnostics to ensure that
the modem is communicating properly with the computer.
The Now SMS/MMS gateway can simultaneously support multiple modems,
provided that your computer hardware has the available communications port
resources.
4.7.3 SMART
MODEM (GSM/GPRS)
PRODUCT DESCRIPTION: 
Physical Characteristics
Temperature Range:
Operating temperature: from -200C to +550C
Make sure that the ejector is pushed out completely before accessing the
SIM Card holder do not remove the SIM card holder by force or tamper it (it may
permanently damage). Place the SIM Card Properly as per the direction of the
installation. It is very important that the SIM is placed in the right
direction for its proper working condition
Connecting External Antenna: Connect
GSM Smart Modem to the external antenna with cable end with SMA male. The
Frequency of the antenna may be GSM 900/1800 MHz. The antenna may be ( 0 dbi, 3
dbi or short length L-type antenna) as per the field conditions and signal
conditions.
Connecting Modem to external devices:
RS232 can be used to connect to the external device through the D-SUB/ USB
(for USB model only) device that is provided in the modem.
Connectors:
Description of the interfaces:
The modem comprises several interfaces:
·
LED Function including operating Status
·
External antenna (via SMA)
·
Serial and control link
·
Power Supply (Via 2 pin Phoenix tm contact)
·
SIM card holder
LED Status Indicator: 
Protecting Modem:
Do not expose to the modem to extreme conditions such as High
temperatures, direct sunlight, High Humidity, Rain, Chemicals, Water, Dust etc.
For these details see the specifications given.
Infrared (IR)
radiation is part of the electromagnetic spectrum, which includes radio waves,
microwaves, visible light, and ultraviolet light, as well as gamma rays and
X-rays. The IR range falls between the visible portion of the spectrum and
radio waves. IR wavelengths are usually expressed in microns, with the lR
spectrum extending from 0.7 to
1000microns. Using advanced optic systems and detectors, non-contact IR
thermometers can focus on nearly any portion or portions of the 0.7-14 micron
band. Because every object (with the exception of a blackbody) emits an optimum
amount of IR energy at a specific point along the IR band, each process may
require unique sensor models with specific optics and detector types. For
example, a sensor with a narrow spectral range center data 3.43 microns is optimized
for measuring the surface temperature of polyethylene and related materials. A
sensor set up for 5 microns is used to measure glass surfaces. A micron sensor
is used for metals and foils. The broader spectral ranges are used to measure
lower temperature surfaces, such as paper, board, poly, and foil composites.
The intensity of
an object's emitted IR energy increases or decreases in proportion to its
temperature. It is the emitted energy, measured as the target's emissivity that
indicates an object's temperature. Emissivity is a term used to quantify the
energy-emitting characteristics of different materials and surfaces. IR sensors
have adjustable emissivity settings, usually from 0.1 to 1.0, which allow
accurate temperature measurements of several surface types. The emitted energy
comes from an object and reaches the IR sensor through its optical system,
which focuses the energy onto one or more photosensitive
detectors. The detector then converts the IR energy into an electrical signal,
which is in turn converted into a temperature value. Based on the sensor's
calibration equation and the target's emissivity. This temperature value can be
displayed on the sensor or, in the case of the smart sensor, converted to a
digital output and displayed on a computer terminal. IR remote
controls use wavelengths between 850 - 950nm. At this short wavelength, the
light is invisible to the human eye, but a domestic camcorder can actually view
this portion of the electromagnetic spectrum. Viewed with a camcorder, an IR
LED appears to change brightness.
All remote controls use an encoded
series of pulses, of which there are thousands of combinations. The light
output intensity varies with each remote control, remotes working at 4.5V dc
generally will provide a stronger light output than a 3V dc control. Also, as
the photodiode in this project has a peak light response at 850nm, it will
receive a stronger signal from controls operating closer to this
wavelength. The photodiode will actually respond to IR wavelengths from 400nm
to 1100nm,so all remote controls should be compatible.
A sensor is a type of transducer, or
mechanism, that responds to a type of energy by producing another type of
energy signal, usually electrical. They are either direct indicating (an
electrical meter) or are paired with an indicator (perhaps indirectly through
an analog to digital converter, a computer and a display) so that the value
sensed is translated for human understanding. Types of sensors include
electromagnetic, chemical, biological and acoustic. Aside from other
applications, sensors are heavily used in medicine, industry& robotics.
In order to act as an effectual
sensor, the following guidelines must be met:
- the sensor should be sensitive to the measured
property
- the sensor should be insensitive to any other
property
- the sensor should not influence the measured
property
In theory, when the sensor is working
perfectly, the output signal of a sensor is exactly proportional to the value
of the property it is meant to measure. The gain is then defined as the ratio
between output signal and measured property. For example, if a sensor measures
temperature and has an actual voltage output, the gain is a constant with the
unit.
When the sensor is not perfect, various deviations can occur, including gain error, long term drift, and noise. These and other deviations can be classified as systematic, or random, errors. Systematic deviations may be compensated for by means of some kind of calibration strategy. Noise is an example of a random error that can be reduced by signal processing, such as filtering, usually at the expense of the dynamic behavior of the sensor.
When the sensor is not perfect, various deviations can occur, including gain error, long term drift, and noise. These and other deviations can be classified as systematic, or random, errors. Systematic deviations may be compensated for by means of some kind of calibration strategy. Noise is an example of a random error that can be reduced by signal processing, such as filtering, usually at the expense of the dynamic behavior of the sensor.
A sensor network is a computer
network of spatially distributed devices using sensors to monitor conditions
(such as temperature, sound, vibration, pressure, motion or pollutants) at a
variety of locations. Usually the devices are small and inexpensive, allowing
them to be produced and deployed in large numbers; this constrains their
resources in terms of energy, memory, and computational speed and bandwidth.
Each device is equipped with a radio transceiver, a small micro controller, and
an energy source, most commonly a battery. The devices work off each other to
deliver data to the computer which has been set up to monitor the information.
Sensor networks involve three areas: sensing, communications, and computation
(hardware, software, algorithms). They are applied in many areas, such as video
surveillance, traffic monitoring, home monitoring and manufacturing. Here the
IR transmitter is nothing but the IR LED. It just looks like a normal LED but
transmits the IR signals. Since the IR rays are out of the visible range we
cannot observe the rays from the transmitter. These
are infrared LEDs; the light output is not visible by our eyes. They can be
used as replacement LEDs for remote controls, night vision for camcorders,
invisible beam sensors, etc.
Infrared
LEDs are ideal light sources for use with night vision goggles, surveillance
cameras, medical imaging, recognition and calibration systems.
Due
to their resistance to ambient-light impediments and electromagnetic
interference (EMI), Infrared LEDs enhance the performance of wireless
computer-to-PDA links, collision avoidance systems, automation equipment,
biomedical instrumentation, and telecommunications equipment.
Solid-state
design renders Infrared LEDs impervious to electrical and mechanical shock,
vibration, frequent switching and environmental extremes. With an average life
span of 100,000-plus hours (11 years), Infrared LEDs operate reliably
year-after-year.
4.5.2
IR RECEIVER (TSOP):
The TSOP17– Series are miniaturized receivers for infrared
remote control systems. PIN diode and preamplifier are assembled on lead frame,
the epoxy package is designed as IR filter. The demodulated output signal can
directly be decoded by a microprocessor. TSOP17.. is the standard IR remote
control receiver series, supporting all major transmission codes.
Features
·
Photo
detector and preamplifier in one package
·
Internal
filter for PCM frequency
·
Improved
shielding against electrical field disturbance
·
TTL
and CMOS compatibility
·
Output
active low
·
Low
power consumption
·
High
immunity against ambient light
·
Continuous
data transmission possible (up to 2400 bps)
·
Suitable
burst length .10 cycles/burst
The circuit of the TSOP17 is designed in that way that
unexpected output pulses due to noise or disturbance signals are avoided. A
bandpass filter, an integrator stage and an automatic gain control are used to
suppress such disturbances. The distinguishing mark between data signal and
disturbance signal are carrier frequency, burst length and duty cycle. The data
signal should fulfill the following condition• Carrier frequency should be
close to center frequency of the band pass (e.g. 38 kHz). Burst length should
be 10 cycles/burst or longer. • After each burst which is between 10 cycles and
70cycles a gap time of at least 14 cycles is necessary. For each burst, which is longer than 1.8ms, a
corresponding gap time is necessary at some time in the data stream. This gap
time should have at least same length as the burst. • Up to 1400 short bursts
per second can be received continuously. Some examples for suitable data format
are: NEC Code, Toshiba Micom Format, Sharp Code, RC5 Code, RC6 Code, R–2000
Code, Sony Format (SIRCS).When a disturbance signal is applied to the TSOP17. it
can still receive the data signal. However the sensitivity is reduced to that
level that no unexpected pulses will occur. Some examples for such disturbance
signals which are suppressed by the TSOP17are:
• DC light (e.g. from tungsten bulb or sunlight)
• Continuous signal at 38kHz or at any other frequency Signals from fluorescent lamps with
electronic ballast.
4.6 GLOBAL POSITION SYSTEM
4.6.1 About GPS
Global
Positioning System (GPS) technology is changing the way we work and play. You
can use GPS technology when you are driving, flying, fishing, sailing, hiking,
running, biking, working, or exploring. With a GPS receiver, you have an
amazing amount of information at your fingertips. Here are just a few examples
of how you can use GPS technology.
- Know precisely
how far you have run and at what pace while tracking your path so you can
find your way home.
- Pinpoint the perfect
fishing spot on the water and easily relocate it.
- Get the closest
location of your favorite restaurant when you are out-of-town.
- Find the
nearest airport or identify the type of airspace in which you are flying
4.6.2 What is GPS?
The
Global Positioning System (GPS) is a satellite-based navigation system that
sends and receives radio signals. A GPS receiver acquires these signals and
provides you with information. Using GPS technology, you can determine
location, velocity, and time, 24 hours a day, in any weather conditions
anywhere in the world—for free.
GPS,
formally known as the NAVSTAR (Navigation Satellite Timing and Ranging). Global
Positioning System originally was developed for the military. Because of its
popular navigation capabilities and because you can access GPS technology using
small, inexpensive equipment, the government made the system available for
civilian use. The USA owns GPS technology and the Department of Defense
maintains it.
GPS
technology requires the following three segments.
·
Space segment.
·
Control segment.
·
User segment
Space Segment
At
least 24 GPS satellites orbit the earth twice a day in a specific pattern. They
travel at approximately 7,000 miles per hour about 12,000 miles above the
earth’s surface. These satellites are spaced so that a GPS receiver anywhere in
the world can receive signals from at least four of them.
·
Each GPS satellite constantly sends coded
radio signals (pseudorandom code) to
the earth. These GPS satellite signals contain the following information.
·
The particular satellite that is sending the
information.
·
Where that satellite should be at any given
time (the precise location of the satellite is. called ephemeris data).
·
Whether or not the satellite is working
properly.
·
The date and time that the satellite sent
the signal.
The
signals can pass through clouds, glass, and plastic. Most solid objects such as
buildings attenuate (decrease the power of) the signals. The signals cannot
pass through objects that contain a lot of metal or objects that contain water
(such as underwater locations). The GPS satellites are powered by solar energy.
If solar energy is unavailable, for example, when the satellite is in the
earth’s shadow, satellites use backup batteries to continue running. Each GPS
satellite is built to last about 10 years. The Department of Defense monitors
and the satellites to ensure that GPS technology continues to run smoothly for
years to come.
The
control segment is responsible for constantly monitoring satellite health,
signal integrity, and orbital configuration from the ground control segment
includes the following sections:
·
Master control station
·
Monitor stations
·
Ground antennas
Monitor Stations
At
least six unmanned monitor stations are located around the world. Each station
constantly monitors and receives information from the GPS satellites and then
sends the orbital and clock information to the master control station (MCS).
Master Control Station (MCS)
The
MCS) is located near Colorado Springs in Colorado. The MCS constantly receives
GPS satellite orbital and clock information from monitor stations. The
controllers in the MCS make precise corrections to the data as necessary, and
send the information (known as ephemeris data) to the GPS satellites using the
ground antennas.
Ground Antennas
Ground
antennas receive the corrected orbital and clock information from the MCS, and
then send the corrected information to the appropriate satellites.
User Segment
The
GPS user segment consists of your GPS receiver. Your receiver collects and
processes signals from the GPS satellites that are in view and then uses that
information to determine and display your location, speed, time, and so forth.
Your GPS receiver does not transmit any information back to the satellites.
4.6.3 How Does GPS
Technology Work?
The following points provide a summary of
the technology at work:
1)
The control segment constantly monitors the
GPS constellation and uploads information to satellites to provide maximum user
accuracy
2)
Your GPS receiver collects information from
the GPS satellites that are in view.
3)
Your GPS receiver accounts for errors. For
more information, refer to the Sources of Errors.
4)
Your GPS receiver determines your current
location, velocity, and time.
5)
Your GPS receiver can calculate other
information, such as bearing, track, trip distance, and distance to
destination, sunrise and sunset time so forth.
6)
Your GPS receiver displays the applicable
information on the screen.
4.6.4
Who Uses GPS?
GPS
technology has many amazing applications on land, at sea, and in the air. You
might be surprised to learn about the following examples of how people or
professions are already using GPS technology
Agriculture:
In
precision farming, GPS technology helps monitor the application of fertilizer
and pesticides. GPS technology also provides location information that helps
farmers plow, harvest, map fields, and mark areas of disease or weed
infestation.
Aviation:
Aircraft
pilots use GPS technology for en route navigation and airport approaches.
Satellite navigation provides accurate aircraft location anywhere on or near
the earth.
Environment:
GPS
technology helps survey disaster areas and maps the movement of environmental
phenomena (such as forest fires, oil spills, or hurricanes). It is even
possible to find locations that have been submerged or altered by natural
disasters.
Ground Transportation:
GPS
technology helps with automatic vehicle location and in-vehicle navigation
systems. Many navigation systems show the vehicle’s location on an electronic
street map, allowing drivers to keep track of where they are and to look up
other destinations. Some systems automatically create a route and give
turn-by-turn directions. GPS technology also helps monitor and plan routes for
delivery vans and emergency vehicles.
Marine:
GPS
technology helps with marine navigation, traffic routing, underwater surveying,
navigational hazard location, and mapping. Commercial fishing fleets use it to
navigate to optimum fishing locations and to track fish migrations.
Military:
Military
aircraft, ships, submarines, tanks, jeeps, and equipment use GPS technology for
many purposes including basic navigation, target designation, close air support,
weapon technology, and rendezvous.
Public Safety:
Emergency
and other specialty fleets use satellite navigation for location and status
information.
Rail:
Precise
knowledge of train location is essential to prevent collisions, maintain smooth
traffic flow, and minimize costly delays. Digital maps and onboard inertial
units allow fully-automated train control.
Recreation:
Outdoor
and exercise enthusiasts use GPS technology to stay apprised of location,
heading, bearing, speed, distance, and time. In addition, they can accurately
mark and record any location and return to that precise spot.
Space:
GPS
technology helps track and control satellites in orbit. Future booster rockets
and reusable launch vehicles will launch, orbit the earth. Return, and land,
all under automatic control. Space shuttles also use GPS navigation.
Surveying:
Surveyors
use GPS technology for simple tasks (such as defining property lines) or for
complex tasks (such as building infrastructures in urban centers). Locating a
precise point of reference used to be very time consuming. With GPS technology,
two people can survey dozens of control points in an hour. Surveying and
mapping roads and rail systems can also be accomplished from mobile platforms
to save time and money.
Timing:
Delivering
precise time to any user is one of the most important functions of GPS
technology. This technology helps synchronize clocks events around the world.
Pager companies depend on GPS satellites to synchronize the transmission of
information throughout their systems. Investment banking firms rely on this
service every day to record international transactions simultaneously.
4.6.5
How Accurate Is GPS?
GPS
technology depends on the accuracy of signals that travel from GPS satellites
to a GPS receiver. You can increase accuracy by ensuring that when you use (or
at least when you turn on) your GPS receiver, you are in an area with few or no
obstacles between you and the wide open sky. When you first turn on your GPS
receiver, stand in an open area for a few moments to allow the unit to get a good fix on the satellites (especially if you are heading into an
obstructed area). This gives you better accuracy for a longer period of time
(about 4-6 hours). It
takes between 65 and 85 milliseconds for a signal to travel from GPS satellite
to a GPS receiver on the surface of the earth.
WAAS/EGNOS:
The
Wide Area Augmentation System (WAAS) is a system of satellites and ground
stations that provides even better position accuracy than the already highly
accurate GPS. Europe’s version of this system is the European Geostationary
Navigation Overlay Service (EGNOS). The Federal Aviation Administration (FAA)
developed the WAAS program. It makes more airspace usable to pilots, provides
more direct end route paths, and provides new precision approach services to
runways, resulting in safety and capacity improvements in all weather
conditions at all locations throughout the U.S. National Airspace System (NAS).
Although
it was designed for aviation users, WAAS supports a wide variety of other uses,
for example, more precise marine navigation. To take advantage of WAAS
technology, you must have a WAAS-capable GPS receiver in an area where WAAS
satellite coverage is available such as North America. No additional equipment
or fees are required to take advantage of WAAS.
Sources of Errors:
Errors
can affect the accuracy of the GPS signal. Take your GPS receiver to an area
with a wide and unobstructed view of the sky to reduce the possibility and
impact of some errors. Here are some of the most common GPS errors.
Ionosphere and Troposphere
Delays:
The
satellite signal slows down as it passes through the atmosphere. The system
uses a built-in model that calculates an average delay to partially correct
this type of error.
Orbital Errors:
This
terminology refers to inaccuracies of the satellite’s reported location.
Receiver Clock Errors:
The
GPS receiver has a built-in clock that can have small timing errors.
Number of Satellites
Visible:
Obstructions
can block signal reception, causing position errors or no position reading. The
more satellites that your GPS receiver can view, the better the fix is.
Satellite Geometry/Shading:
Refers
to the relative position of the satellites at any given time. Ideal satellite
geometry exists when the satellites are located at wide angles relative to each
other. Poor geometry results when the satellites are located in a line or in a
tight grouping.
Signal Multipath:
The
GPS signal bounces off of objects, such as tall buildings or large rock
surfaces, before it reaches the GPS receiver. This increases the travel time of
the signal and, therefore, causes errors.
Buying a GPS Receiver:
Deciding
which GPS receiver to buy can be overwhelming. Think about how you want to use
the unit, for example, traveling or running. Keep the following considerations
in mind:
Product Level
Do you want the basics, or do you want all
of the bells and whistles? You can find a unit that fits your needs and budget.
Power Source:
Will
you be using the unit away from an auxiliary power source? You might need to
carry extra batteries. With some you can use a vehicle adapter or AC power
source.
Portability:
Do
you have a preference between a portable or a built-in unit? Some units mount
directly in the dashboard of your boat or aircraft.
Mapping Capability:
Do
you want to know the general direction or street-level details of your chosen
path? Map data can include streets restaurants, tourist attractions, marine
data, topography, and so forth.
Mounts:
A
mount for your GPS can be useful to keep your hands free while navigating your
bike, boat, car, or airplane. Many units with a mount, and several additional
mounts are available.
Ease of Use:
Some
receivers provide a tutorial or an easy-to-use touch screen interface. Some
even have turn-by-turn voice instructions you are navigating your route.
Antenna Configuration:
Where
are you going to use the unit? With some units, you use only the built-in
antenna. With other units, you attach an external antenna to give you better
reception
Price:
Which
units fit your price range? An inexpensive entry-level unit can be a great way
to enter the GPS world.
Software:
Whether
you want to save your favorite locations or plan a trip, map software can help.
You can use your PC or go directly your GPS receiver. Your preference for map
detail and your specific activities determine which software is right for you.
Complementary Navigation
Aids:
Remember,
a GPS receiver is a complement to navigation and should not be the only
navigational tool that you use. Using a paper map, a simple compass, and having
knowledge of manual navigation is a good, safe practice.
4.6.6 Pin
assignment:
4.7.1Definition:
Global system for mobile communication (GSM) is a globally accepted
standard for digital cellular communication. GSM is the name of a
standardization group established in 1982 to create a common European mobile
telephone standard that would formulate specifications for a pan-European
mobile cellular radio system operating at 900 MHz. It is estimated that many
countries outside of Europe will join the GSM partnership.
4.7.2 Description:
GSM, the Global System for Mobile communications, is a digital cellular
communications system, which has rapidly gained acceptance and market share
worldwide, although it was initially developed in a European context. In
addition to digital transmission, GSM incorporates many advanced services and
features, including ISDN compatibility and worldwide roaming in other GSM
networks. The advanced services and architecture of GSM have made it a model
for future third-generation cellular systems, such as UMTS. This paper will
give an overview of the services offered by GSM, the system architecture, the
radio transmission
A GSM modem can be an external modem device, such as the Wavecom FASTRACK
Modem. Insert a GSM SIM card into this
modem, and connect the modem to an available serial port on your computer.
A GSM modem can be a PC Card installed in a notebook computer, such as
the Nokia Card Phone.
A GSM modem could also be a standard GSM mobile phone with the
appropriate cable and software driver to connect to a serial port on your
computer. Phones such as the Nokia 7110
with a DLR-3 cable, or various Ericsson phones, are often used for this
purpose.
A dedicated GSM modem (external or PC Card) is usually preferable to a
GSM mobile phone. This is because of some
compatibility issues that can exist with mobile phones. For example, if you wish to be able to
receive inbound MMS messages with your gateway, and you are using a mobile
phone as your modem, you must utilize a mobile phone that does not support WAP
push or MMS. This is because the mobile
phone automatically processes these messages, without forwarding them via the
modem interface. Similarly some mobile
phones will not allow you to correctly receive SMS text messages longer than
160 bytes (known as “concatenated SMS” or “long SMS”). This is because these long messages are
actually sent as separate SMS messages, and the phone attempts to reassemble
the message before forwarding via the modem interface. (We’ve observed this latter problem utilizing
the Ericsson R380, while it does not appear to be a problem with many other
Ericsson models.)
When you install your GSM modem, or connect your GSM mobile phone to the
computer, be sure to install the appropriate Windows modem driver from the
device manufacturer. To simplify
configuration, the Now SMS/MMS Gateway will communicate with the device via
this driver. An additional benefit of
utilizing this driver is that you can use Windows diagnostics to ensure that
the modem is communicating properly with the computer.
The Now SMS/MMS gateway can simultaneously support multiple modems,
provided that your computer hardware has the available communications port
resources.
4.7.3 SMART
MODEM (GSM/GPRS)
Analogic’s GSM Smart Modem is a multi-functional, ready to use, rugged
and versatile modem that can be embedded or plugged into any application. The
Smart Modem can be customized to various applications by using the standard AT
commands. The modem is fully type-approved and can directly be integrated into
your projects with any or all the features of Voice, Data, Fax, SMS, and
Internet etc.
Smart Modem kit contain the following items:
1)
Analogic’s GSM/GPRS Smart Modem
2)
SMPS based power
supply adapter.
3)
dBi antenna with cable (optional: other types)
4)
Data cable (RS232)
5)
User Manual
PRODUCT DESCRIPTION:
The connectors integrated to the body, guarantee the
reliable output and input connections. An extractible holder is used to insert
the SIM card (Micro-SIM type). Status LED indicates the operating mode.
Operating temperature: from -200C to +550C
Storage temperature: from -250C to +700C
Installing the modem:
To install the modem, plug the device on to the supplied SMPS Adapter.
For Automotive applications fix the modem permanently using the mounting slots
(optional as per your requirement dimensions).
Inserting/ Removing the SIM Card:
To insert or Remove the SIM Card, it is necessary to press the SIM holder
ejector button with Sharp edged object like a pen or a needle. With this, the
SIM holder comes out a little, then pulls it out and insert or remove the SIM
Card
Connecting External Antenna: Connect
GSM Smart Modem to the external antenna with cable end with SMA male. The
Frequency of the antenna may be GSM 900/1800 MHz. The antenna may be ( 0 dbi, 3
dbi or short length L-type antenna) as per the field conditions and signal
conditions.
DC Supply Connection
The Modem will automatically turn ON when connection is given to it. The
following is the Power Supply Requirement:
RS232 can be used to connect to the external device through the D-SUB/ USB
(for USB model only) device that is provided in the modem.
Connectors:
The modem comprises several interfaces:
·
LED Function including operating Status
·
External antenna (via SMA)
·
Serial and control link
·
Power Supply (Via 2 pin Phoenix tm contact)
·
SIM card holder
LED Status Indicator:
The LED will indicate different status of the modem:
OFF Modem
Switched off
ON Modem
is connecting to the network
Flashing Slowly Modem is in
idle mode
Flashing rapidly Modem is
in transmission/communication (GSM only)
Do not expose to the modem to extreme conditions such as High
temperatures, direct sunlight, High Humidity, Rain, Chemicals, Water, Dust etc.
For these details see the specifications given.
·
Do
not drop, Shake or hit the Modem. (Warranty may void)
·
The
Modem should not be used in extreme vibrating conditions
·
Handle
the Antenna and cable with care.
4.7.4 AT commands features:
Line settings:
A serial link handler is set with the following default
values Autobaud, 8 bits data, 1 stop bit, no parity, flow control.
Ø Command line
Ø Commands always start with AT (which
means attention) and finish with a <CR> character.
Ø Information responses and result
codes
Ø Responses start and end with
<CR><LF>,.
Ø If command syntax is incorrect, an
ERROR string is returned.
Ø If command syntax is correct but with
some incorrect parameters, the +CME ERROR: <Err> or +CMS ERROR:
<SmsErr> strings are returned with different error codes.
Ø If the command line has been
performed successfully, an OK string is returned.
Ø In some cases, such as “AT+CPIN?” or
(unsolicited) incoming events, the product does not return the OK string as a
response.
4.7.5 Services provided by GSM
GSM was designed having interoperability with ISDN in mind,
and the services provided by GSM are a subset of the standard ISDN services.
Speech is the most basic, and most important, teleservice provided by GSM.
In addition, various data services are supported, with user
bit rates up to 9600 bps. Specially equipped GSM terminals can connect with
PSTN, ISDN, Packet Switched and Circuit Switched Public Data Networks, through
several possible methods, using synchronous or asynchronous transmission. Also
supported are Group 3 facsimile service, videotex, and teletex. Other GSM
services include a cell broadcast service, where messages such as traffic
reports, are broadcast to users in particular cells.
A service unique to GSM, the Short Message Service, allows
users to send and receive point-to-point alphanumeric messages up to a few tens
of bytes. It is similar to paging services, but much more comprehensive,
allowing bi-directional messages, store-and-forward delivery, and
acknowledgement of successful delivery.
Supplementary services enhance the set of basic teleservices.
In the Phase I specifications, supplementary services include variations of
call forwarding and call barring, such as Call Forward on Busy or Barring of
Outgoing International Calls. Many more supplementary services, including
multiparty calls, advice of charge, call waiting, and calling line
identification presentation will be offered in the Phase 2 specifications.
4.7.6
Architecture of the GSM network:
A GSM network is composed of several functional entities,
whose functions and interfaces are specified. Figure 1 shows the layout of a
generic GSM network. The GSM network can be divided into three broad parts. The
Mobile Station is carried by the subscriber. The Base Station Subsystem
controls the radio link with the Mobile Station. The Network Subsystem, the
main part of which is the Mobile services Switching Center (MSC), performs the
switching of calls between the mobile users, and between mobile and fixed
network users. The MSC also handles the mobility management operations. Not
shown are the Operations
4.7.6.1
Mobile Station:
The mobile station (MS) consists of the mobile equipment (the
terminal) and a smart card called the Subscriber Identity Module (SIM). The SIM
provides personal mobility, so that the user can have access to subscribed
services irrespective of a specific terminal. By inserting the SIM card into another
GSM terminal, the user is able to receive calls at that terminal, make calls
from that terminal, and receive other subscribed services.
A GSM network is composed of several functional entities,
whose functions and interfaces are specified. Figure 1 shows the layout of a
generic GSM network. The GSM network can be divided into three broad parts. The
Mobile Station is carried by the subscriber. The Base Station Subsystem
controls the radio link with the Mobile Station. The Network Subsystem, the
main part of which is the Mobile services Switching Center (MSC), performs the
switching of calls between the mobile users, and between mobile and fixed
network users. The MSC also handles the mobility management operations. Not
shown are the Operations
A GSM network is composed of several functional entities,
whose functions and interfaces are specified. Figure 1 shows the layout of a
generic GSM network. The GSM network can be divided into three broad
parts. Subscriber carries the Mobile
Station. The Base Station Subsystem controls the radio link with the Mobile
Station. The Network Subsystem, the main part of which is the Mobile services
Switching Center (MSC), performs the switching of calls between the mobile
users, and between mobile and fixed network users. The MSC also handles the
mobility management operations. Not shown is the Operations intendance Center,
which oversees the proper operation and setup of the network. The Mobile
Station and the Base Station Subsystem communicate across the Um interface,
also known as the air interface or radio link. The Base Station Subsystem
communicates with the Mobile services Switching Center across the A interface.
The mobile station (MS) consists of the mobile equipment (the
terminal) and a smart card called the Subscriber Identity Module (SIM). The SIM
provides personal mobility, so that the user can have access to subscribed
services irrespective of a specific terminal. By inserting the SIM card into another
GSM terminal, the user is able to receive calls at that terminal, make calls
from that terminal, and receive other subscribed services.
The mobile equipment is uniquely identified by the
International Mobile Equipment Identity (IMEI). The SIM card contains the
International Mobile Subscriber Identity (IMSI) used to identify the subscriber
to the system, a secret key for authentication, and other information. The IMEI
and the IMSI are independent, thereby allowing personal mobility. The SIM card
may be protected against unauthorized use by a password or personal identity
number.
4.7.6.2
Base Station Subsystem:
The Base Station Subsystem is composed of two parts, the Base
Transceiver Station (BTS) and the Base Station Controller (BSC). These
communicate across the standardized Abis interface, allowing (as in the rest of
the system) operation between components made by different suppliers.
The Base Transceiver Station houses the radio transceivers
that define a cell and handles the radio-link protocols with the Mobile
Station. In a large urban area, there will potentially be a large number of
BTSs deployed, thus the requirements for a BTS are ruggedness, reliability,
portability, and minimum cost.
The Base Station Controller manages the radio resources for
one or more BTSs. It handles radio-channel setup, frequency hopping, and
handovers, as described below. The BSC is the connection between the mobile
station and the Mobile service Switching Center (MSC).
4.7.6.3 Network Subsystem
The central component of the Network Subsystem is the Mobile
services Switching Center (MSC). It acts like a normal switching node of the
PSTN or ISDN, and additionally provides all the functionality needed to handle
a mobile subscriber, such as registration, authentication, location updating,
handovers, and call routing to a roaming subscriber. These services are
provided in conjunction with several functional entities, which together form
the Network Subsystem. The MSC provides the connection to the fixed networks
(such as the PSTN or ISDN). Signaling between functional entities in the
Network Subsystem uses Signaling System Number 7 (SS7), used for trunk signaling
in ISDN and widely used in current public networks.
The central component of the Network Subsystem is the Mobile
services Switching Center (MSC). It acts like a normal switching node of the
PSTN or ISDN, and additionally provides all the functionality needed to handle
a mobile subscriber, such as registration, authentication, location updating,
handovers, and call routing to a roaming subscriber. These services are
provided in conjunction with several functional entities, which together form
the Network Subsystem. The MSC provides the connection to the fixed networks
(such as the PSTN or ISDN). Signaling between functional entities in the
Network Subsystem uses Signaling System Number 7 (SS7), used for trunk signaling
in ISDN and widely used in current public networks.
The Home Location Register (HLR) and Visitor Location
Register (VLR), together with the MSC, provide the call-routing and roaming
capabilities of GSM. The HLR contains all the administrative information of
each subscriber registered in the corresponding GSM network, along with the
current location of the mobile. The location of the mobile is typically in the
form of the signaling address of the VLR associated with the mobile as a
distributed database. station. The actual routing procedure will be described
later. There is logically one HLR per GSM network, although it may be
implemented
The Visitor Location Register (VLR) contains selected
administrative information from the HLR, necessary for call control and
provision of the subscribed services, for each mobile currently located in the
geographical area controlled by the VLR. Although each functional entity can be
implemented as an independent unit, all manufacturers of switching equipment to
date implement the VLR together with the MSC, so that the geographical area
controlled by the MSC corresponds to that controlled by the VLR, thus
simplifying the signalling required. Note that the MSC contains no information
about particular mobile stations --- this information is stored in the location
registers.
The other two registers are used for authentication and
security purposes. The Equipment Identity Register (EIR) is a database that
contains a list of all valid mobile equipment on the network, where each mobile
station is identified by its International Mobile Equipment Identity (IMEI). An
IMEI is marked as invalid if it has been reported stolen or is not type
approved. The Authentication Center (AuC) is a protected database that stores a
copy of the secret key stored in each subscriber's SIM card, which is used for
authentication and encryption over the radio channel.
4.8 LIQUID CRYSTAL DISPLAY:
Liquid crystal displays (LCDs) have
materials, which combine the properties of both liquids and crystals. Rather
than having a melting point, they have a temperature range within which the
molecules are almost as mobile as they would be in a liquid, but are grouped
together in an ordered form similar to a crystal. An LCD consists of two glass
panels, with the liquid crystal material sand witched in between them. The
inner surface of the glass plates are coated with transparent electrodes which
define the character, symbols or patterns to be displayed polymeric layers are
present in between the electrodes and the liquid crystal, which makes the
liquid crystal molecules to maintain a defined orientation angle. One each
polarisers are pasted outside the two glass panels. These polarisers would
rotate the light rays passing through them to a definite angle, in a particular
direction. When the LCD is in the off state, light rays are rotated by the two
polarisers and the liquid crystal, such that the light rays come out of the LCD
without any orientation, and hence the LCD appears transparent.
When sufficient voltage is applied to
the electrodes, the liquid crystal molecules would be aligned in a specific
direction. The light rays passing through the LCD would be rotated by the
polarisers, which would result in activating/ highlighting the desired
characters. The LCD’s are lightweight with only a few millimeters thickness.
Since the LCD’s consume less power, they are compatible with low power
electronic circuits, and can be powered for long durations. The LCD’s don’t
generate light and so light is needed to read the display. By using
backlighting, reading is possible in the dark. The LCD’s have long life and a
wide operating temperature range. Changing the display size or the layout size
is relatively simple which makes the LCD’s more customers friendly.
4.8.1 LCD operation:
- In recent years the LCD is finding widespread
use replacing LEDs(seven-segment LEDs
or other multisegment LEDs).This is due to the following reasons:
- The declining prices of LCDs.
- The ability to display numbers, characters and
graphics. This is in contract to
LEDs, which are limited to numbers
and a few characters.
- Incorporation of a refreshing controller into the
LCD, there by
- relieving the CPU of the task of refreshing the
LCD. In the contrast,
- the LED must be refreshed by the CPU to keep displaying the data.
- Ease of programming for characters and graphics.
16X2
LCD:
PIN
DESCRIPTION OF LCD:
RS:
REGISTER SELECT:
0x38: 2 lines and 5x7 matrix
- In recent years the LCD is finding widespread
use replacing LEDs(seven-segment LEDs
or other multisegment LEDs).This is due to the following reasons:
- The declining prices of LCDs.
- The ability to display numbers, characters and
graphics. This is in contract to
LEDs, which are limited to numbers
and a few characters.
- Incorporation of a refreshing controller into the
LCD, there by
- relieving the CPU of the task of refreshing the
LCD. In the contrast,
- the LED must be refreshed by the CPU to keep displaying the data.
- Ease of programming for characters and graphics.
16X2
LCD:
RS:
REGISTER SELECT:
Ø there are two registers inside the
LCD.
Ø Command Register and Data Register.
Ø RS pin is used for their selection.
·
if
RS=0, command register is selected.
·
if
RS=1, data register is selected.
R/W:
READ/WRITE
§ Allows user to read the information
from the LCD and write the information to the LCD.
R/W=1
when reading
R/W=0,
when writing
E: ENABLE
§ used by the LCD to latch the information
from its data lines.
§ a high to low pulse must be applied
to this pin to receive data.
§ this pulse must be 450ns wide.
VCC: +5V POWER SUPPLY
VSS: GROUND
VEE: TO CONTROL LCD CONTRAST.
D0-D7: 8 Bit data pins used to send information to the LCD or read the
contents of the LCD’s internal registers.
LCD
COMMANDS:
0x38: 2 lines and 5x7 matrix
0x01: clear display screen
0x0E: display on, cursor blinking
0x06: increment cursor(shift cursor to
right)
0x80: force cursor to beginning of 1st
line
0xC0: force cursor to beginning of 2nd line
ALGORITHM
TO SEND DATA TO LCD:
•
1.Make
R/W low
•
2.Make
RS=0 ;if data byte is command
RS=1 ;if data byte is data (ASCII value)
•
3.Place
data byte on data register
•
4.Pulse
E (HIGH to LOW)
•
5.Repeat
the steps to send another data byte
4.9
ignition switch:
The term ignition switch is often used interchangeably to refer to two
very different parts. The lock cylinder into which the key is inserted, and the
electronic switch that sits just behind the lock cylinder. In some cars, these
two parts are combined into one unit, but in other cars they remain separate.
It is advisable to check your car's shop manual before attempting to purchase
an ignition switch, to ensure that you buy the correct part.
In order to start a car, the engine
must be turning. Therefore, in the days before ignition switches, car engines
had to be turned with a crank on the front of the car in order to start them.
The starter performs this same operation by turning the engine's flywheel, a large, flat
disc with teeth on the outer edge. The starter has a gear that engages these
teeth when it is powered, rapidly and briefly turning the flywheel, and thus
the engine.
The ignition switch generally has four
positions: off, accessories, on, and start.
Some cars have two off positions, off
and lock; one turns off the
car, and the other allows the key to be removed from the ignition. When the key
is turned to the accessories
position, certain accessories, such as the radio, are powered; however,
accessories that use too much battery power, such as window motors, remain off
in order to prevent the car's battery from being drained. The accessories position uses the least
amount of battery power when the engine is not running, which is why drive-in
movie theaters recommend that the car be left in the accessories mode during the movie.
The on position turns on all of the car's systems, including systems
such as the fuel pump,
because this is the position the ignition switch remains in while the car's
engine is running. The start
position is spring loaded so that the ignition switch will not remain there
when the key is released. When the key is inserted into the ignition switch lock
cylinder and turned to the start
position, the starter engages; when the key is released, it returns to the on position, cutting power to the
starter. This is because the engine runs at speeds that the starter cannot
match, meaning that the starter gear must be retracted once the engine is
running on its own.
Either the ignition switch or the
lock cylinder may fail in a car, but both circumstances have very different
symptoms. When the ignition switch fails, generally the electrical wiring or
the plastic housing develops problems. The car may not turn on and/or start
when this happens. Also, the spring-loaded start position could malfunction, in which case the starter will
not engage unless the key is manually turned back to the on position.
When the lock cylinder malfunctions,
however, the operation of the key itself will become problematic. If the
tumblers become stripped, the lock cylinder may be able to turn with any key,
or you may be able to remove the key when the car is on. If the tumblers begin
to shift, the lock cylinder may not turn. Sometimes the key can be wiggled
until the lock cylinder turns, but it is important to remember that this is
only a temporary fix
4.10 MAX-232:
The
MAX232 from Maxim was the
first IC which in one package contains the necessary drivers (two) and
receivers (also two), to adapt the RS-232 signal voltage levels to TTL logic.
It became popular, because it just needs one voltage (+5V) and generates the
necessary RS-232 voltage levels (approx. -10V and +10V) internally. This
greatly simplified the design of circuitry. Circuitry designers no longer need
to design and build a power supply with three voltages (e.g. -12V, +5V, and
+12V), but could just provide one +5V power supply, e.g. with the help of a
simple 78x05 voltage converter.
The MAX232 has a
successor, the MAX232A. The ICs
are almost identical, however, the MAX232A is much more often used (and easier
to get) than the original MAX232, and the MAX232A only needs external
capacitors 1/10th the capacity of what the original MAX232 needs.
It should be noted
that the MAX 232 is just a driver/receiver. It does not generate the necessary
RS-232 sequence of marks and spaces with the right timing, it does not decode
the RS-232 signal, it does not provide a serial/parallel conversion. All it does is to convert signal voltage
levels. Generating serial data with the right timing and decoding serial
data has to be done by additional circuitry, e.g. by a 16550
UART or one of these small micro controllers (e.g. Atmel AVR, Microchip
PIC) getting more and more popular.
The MAX232 and
MAX232A were once rather expensive ICs, but today they are cheap. It has also
helped that many companies now produce clones (ie. Sipex).
These clones sometimes need different external circuitry, e.g. the capacities
of the external capacitors vary. It is recommended to check the data sheet of
the particular manufacturer of an IC instead of relying on Maxim's original
data sheet.
The original
manufacturer (and now some clone manufacturers, too) offers a large series of
similar ICs, with different numbers of receivers and drivers, voltages,
built-in or external capacitors, etc. E.g. The MAX232 and MAX232A need external
capacitors for the internal voltage pump, while the MAX233 has these capacitors
built-in. The MAX233 is also between three and ten times more expensive in
electronic shops than the MAX232A because of its internal capacitors. It is
also more difficult to get the MAX233 than the garden variety MAX232A.
4.10.1 A Typical Application
The MAX 232(A) has two receivers (converts from RS-232 to TTL voltage
levels) and two drivers (converts from TTL logic to RS-232 voltage levels).
This means only two of the RS-232 signals can be converted in each direction.
The old MC1488/1498 combo provided four drivers and receivers.
Typically a pair of a driver/receiver of the MAX232 is used for
·
TX and RX
And the second one for
·
CTS and RTS.
There are not enough drivers/receivers in the MAX232 to also connect the
DTR, DSR, and DCD signals. Usually these signals can be omitted when e.g.
communicating with a PC's serial interface. If the DTE really requires these
signals either a second MAX232 is needed, or some other IC from the MAX232
family can be used (if it can be found in consumer electronic shops at all). An
alternative for DTR/DSR is also given below.
Maxim's data sheet explains the MAX232 family in
great detail, including the pin configuration and how to connect such an IC to
external circuitry. This information can be used as-is in own design to get a
working RS-232 interface. Maxim's data just misses one critical piece of information:
How exactly to connect the RS-232 signals to the IC. So here is one possible
example:
In addition one can directly wire DTR (DB9
pin 4) to DSR (DB9 pin 6) without going through any circuitry. This gives
automatic (brain dead) DSR acknowledgment of an incoming DTRsignal.
Sometimes pin 6 of the MAX232 is hard wired to DCD (DB9 pin 1). This is
not recommended. Pin 6 is the raw output of the voltage pump and inverter for
the -10V voltage. Drawing currents from the pin leads to a rapid breakdown of
the voltage, and as a consequence to a breakdown of the output voltage of the
two RS-232 drivers. It is better to use software which doesn't care about DCD,
but does hardware-handshaking via CTS/RTS only.
The circuitry is completed by connecting five capacitors to the IC as it
follows. The MAX232 needs 1.0µF capacitors, the MAX232A needs 0.1µF capacitors.
MAX232 clones show similar differences. It is recommended to consult the
corresponding data sheet. At least 16V capacitor types should be used. If
electrolytic or tantalic capacitors are used, the polarity has to be observed.
The first pin as listed in the following table is always where the plus pole of
the capacitor should be connected to.
The 5V power supply is connected to
·
+5V: Pin 16
·
GND: Pin 15
The MAX232 is a dual driver/receiver that includes a
capacitive voltage generator to supply EIA-232 voltage levels from a single 5-V
supply. Each receiver converts EIA-232 inputs to 5-V TTL/CMOS levels. These
receivers have a typical threshold of 1.3 V and a typical hysteresis of 0.5 V,
and can accept 30-V inputs. Each driver converts TTL/CMOS input levels into
EIA-232 levels. The driver, receiver, and voltage-generator functions are available
as cells in the Texas Instruments Lin ASIClibrary.
Figure 27: Block
Diagram of the DC motor
Every DC motor has six basic parts -- axle, rotor
(a.k.a., armature), stator, commutator, field magnet(s), and brushes. In most
common DC motors (and all that Beamers will see), the external magnetic field
is produced by high-strength permanent magnets1. The stator is the
stationary part of the motor -- this includes the motor casing, as well as two
or more permanent magnet pole pieces. The rotor (together with the axle and
attached commutator) rotates with respect to the stator. The rotor consists of
windings (generally on a core), the windings being electrically connected to
the commutator. The above diagram shows a common motor layout -- with the rotor
inside the stator (field) magnets.
Figure 28: Block
Diagram of the DC motor having two poles only
Figure 29: Block Diagram of the DC
motor having Three poles
You'll notice a few things from this
-- namely, one pole is fully energized at a time (but two others are
"partially" energized). As each brush transitions from one commutator
contact to the next, one coil's field will rapidly collapse, as the next coil's
field will rapidly charge up (this occurs within a few microsecond). We'll see
more about the effects of this later, but in the meantime you can see that this
is a direct result of the coil windings' series wiring:
The MAX 232(A) has two receivers (converts from RS-232 to TTL voltage
levels) and two drivers (converts from TTL logic to RS-232 voltage levels).
This means only two of the RS-232 signals can be converted in each direction.
The old MC1488/1498 combo provided four drivers and receivers.
Typically a pair of a driver/receiver of the MAX232 is used for
·
TX and RX
And the second one for
·
CTS and RTS.
There are not enough drivers/receivers in the MAX232 to also connect the
DTR, DSR, and DCD signals. Usually these signals can be omitted when e.g.
communicating with a PC's serial interface. If the DTE really requires these
signals either a second MAX232 is needed, or some other IC from the MAX232
family can be used (if it can be found in consumer electronic shops at all). An
alternative for DTR/DSR is also given below.
Maxim's data sheet explains the MAX232 family in
great detail, including the pin configuration and how to connect such an IC to
external circuitry. This information can be used as-is in own design to get a
working RS-232 interface. Maxim's data just misses one critical piece of information:
How exactly to connect the RS-232 signals to the IC. So here is one possible
example:
In addition one can directly wire DTR (DB9
pin 4) to DSR (DB9 pin 6) without going through any circuitry. This gives
automatic (brain dead) DSR acknowledgment of an incoming DTRsignal.
Sometimes pin 6 of the MAX232 is hard wired to DCD (DB9 pin 1). This is
not recommended. Pin 6 is the raw output of the voltage pump and inverter for
the -10V voltage. Drawing currents from the pin leads to a rapid breakdown of
the voltage, and as a consequence to a breakdown of the output voltage of the
two RS-232 drivers. It is better to use software which doesn't care about DCD,
but does hardware-handshaking via CTS/RTS only.
The circuitry is completed by connecting five capacitors to the IC as it
follows. The MAX232 needs 1.0µF capacitors, the MAX232A needs 0.1µF capacitors.
MAX232 clones show similar differences. It is recommended to consult the
corresponding data sheet. At least 16V capacitor types should be used. If
electrolytic or tantalic capacitors are used, the polarity has to be observed.
The first pin as listed in the following table is always where the plus pole of
the capacitor should be connected to.
The 5V power supply is connected to
·
+5V: Pin 16
·
GND: Pin 15
The MAX232 is a dual driver/receiver that includes a
capacitive voltage generator to supply EIA-232 voltage levels from a single 5-V
supply. Each receiver converts EIA-232 inputs to 5-V TTL/CMOS levels. These
receivers have a typical threshold of 1.3 V and a typical hysteresis of 0.5 V,
and can accept 30-V inputs. Each driver converts TTL/CMOS input levels into
EIA-232 levels. The driver, receiver, and voltage-generator functions are available
as cells in the Texas Instruments Lin ASIClibrary.
4.11 DC Motor :
DC motors are configured in many types and sizes,
including brush less, servo, and gear motor types. A motor consists of a rotor and a permanent
magnetic field stator. The magnetic field is maintained using either permanent
magnets or electromagnetic windings. DC motors are most commonly used in variable speed and
torque.
Motion and controls cover a wide range of
components that in some way are used to generate and/or control motion. Areas
within this category include bearings and bushings, clutches and brakes,
controls and drives, drive components, encoders and resolves, Integrated motion
control, limit switches, linear actuators, linear and rotary motion components,
linear position sensing, motors (both AC and DC motors), orientation position sensing,
pneumatics and pneumatic components, positioning stages, slides and guides,
power transmission (mechanical), seals, slip rings, solenoids and springs. Motors are the devices that provide the actual
speed and torque in a drive system. This family includes AC motor types (single and multiphase motors, universal, servo motors, induction, synchronous, and gear motor)
and DC motors (brush less, servo motor, and gear motor) as well as linear,
stepper and air motors, and motor contactors and starters.
In any electric motor, operation is
based on simple electromagnetism. A current-carrying conductor generates a magnetic field; when
this is then placed in an external magnetic field, it will experience a force
proportional to the current in the conductor,
and to the strength of the external magnetic field. As you are well aware of
from playing with magnets as a kid, opposite (North and South) polarities
attract, while like polarities (North and North, South and South) repel. The
internal configuration of a DC motor is designed to harness the magnetic
interaction between a current-carrying conductor
and an external magnetic field to generate rotational motion.
Let's start by looking at a simple
2-pole DC electric motor (here
red represents a magnet or winding with a "North" polarization, while
green represents a magnet or winding with a "South" polarization).
Figure 27: Block
Diagram of the DC motor
Every DC motor has six basic parts -- axle, rotor
(a.k.a., armature), stator, commutator, field magnet(s), and brushes. In most
common DC motors (and all that Beamers will see), the external magnetic field
is produced by high-strength permanent magnets1. The stator is the
stationary part of the motor -- this includes the motor casing, as well as two
or more permanent magnet pole pieces. The rotor (together with the axle and
attached commutator) rotates with respect to the stator. The rotor consists of
windings (generally on a core), the windings being electrically connected to
the commutator. The above diagram shows a common motor layout -- with the rotor
inside the stator (field) magnets.
The geometry of the brushes,
commutator contacts, and rotor windings are such that when power is applied,
the polarities of the energized winding and the stator magnet(s) are
misaligned, and the rotor will rotate until it is almost aligned with the
stator's field magnets. As the rotor reaches alignment, the brushes move to the
next commutator contacts, and energize the next winding. Given our example
two-pole motor, the rotation reverses the direction of current through the
rotor winding, leading to a "flip" of the rotor's magnetic field, and
driving it to continue rotating.
In real life, though, DC motors will always have more than two poles
(three is a very common number). In particular, this avoids "dead
spots" in the commutator. You can imagine how with our example two-pole
motor, if the rotor is exactly at the middle of its rotation (perfectly aligned
with the field magnets), it will get "stuck" there. Meanwhile, with a
two-pole motor, there is a moment where the commutator shorts out the power
supply (i.e., both brushes touch both commutator contacts simultaneously). This
would be bad for the power supply, waste energy, and damage motor components as
well. Yet another disadvantage of such a simple motor is that it would exhibit
a high amount of torque” ripple" (the amount of torque it could produce is
cyclic with the position of the rotor).
Figure 28: Block
Diagram of the DC motor having two poles only
Figure 29: Block Diagram of the DC motor having Three poles
You'll notice a few things from this
-- namely, one pole is fully energized at a time (but two others are
"partially" energized). As each brush transitions from one commutator
contact to the next, one coil's field will rapidly collapse, as the next coil's
field will rapidly charge up (this occurs within a few microsecond). We'll see
more about the effects of this later, but in the meantime you can see that this
is a direct result of the coil windings' series wiring:
Figure 30:
Internal Block Diagram of the Three pole DC motor
There's probably no better way to see
how an average dc motor is put together, than by just opening one up.
Unfortunately this is tedious work, as well as requiring the destruction of a
perfectly good motor. This is a basic
3-pole dc motor, with 2 brushes and three commutator contacts.
4.12 H-BRIDGE:
Figure 31:
H-Bridge
DC motors are
typically controlled by using a transistor configuration called an "H-bridge".
This consists of a minimum of four mechanical or solid-state switches, such as
two NPN and two PNP transistors. One NPN and one PNP transistor are activated
at a time. Both NPN and PNP transistors can be activated to cause a short
across the motor terminals, which can be useful for slowing down the motor from
the back EMF it creates.
4.12.1
Basic Theory
H-bridge. Sometimes called a "full bridge" the
H-bridge is so named because it has four switching elements at the
"corners" of the H and the motor forms the cross bar.
The key fact to note is that there are, in theory, four
switching elements within the bridge. These four elements are often called,
high side left, high side right, low side right, and low side left (when
traversing in clockwise order).
The switches are turned on in pairs, either high left
and lower right, or lower left and high right, but never both switches on the
same "side" of the bridge. If both switches on one side of a bridge
are turned on it creates a short circuit between the battery plus and battery
minus terminals. If the bridge is sufficiently powerful it will absorb that
load and your batteries will simply drain quickly. Usually however the switches
in question melt.
To power the motor, you turn on two switches that are
diagonally opposed. In the picture to the right, imagine that the high side
left and low side right switches are turned on.
The current flows and the motor begins to turn in a
"positive" direction. Turn on the high side right and low side left
switches, then Current flows the other direction through the motor and the
motor turns in the opposite direction.
One more topic in the basic theory section, quadrants.
If each switch can be controlled independently then you can do some interesting
things with the bridge, some folks call such a bridge a "four quadrant
device" (4QD get it?). If you built it out of a single DPDT relay, you can
really only control forward or reverse. You can build a small truth table that
tells you for each of the switch's states, what the bridge will do. As each
switch has one of two states, and there are four switches, there are 16
possible states. However, since any state that turns both switches on one side
on is "bad" (smoke issues forth: P), there are in fact only four
useful states (the four quadrants) where the transistors are turned on.
High
Side Left
High
Side Right
Low
Side Left
Low
Side Right
Quadrant
Description
On
Off
Off
On
Forward
Running
Off
On
On
Off
Backward
Running
On
On
Off
Off
Braking
Off
Off
On
On
Braking
Table
9: H-Bridge truth table
The last two rows describe a maneuver where you
"short circuit" the motor which causes the motors generator effect to
work against itself. The turning motor generates a voltage which tries to force
the motor to turn the opposite direction. This causes the motor to rapidly stop
spinning and is called "braking" on a lot of H-bridge designs. Of
course there is also the state where all the transistors are turned off. In
this case the motor coasts freely if it was spinning and does nothing if it was
doing nothing.
4.12.2
Motor
Driver Connections: 
Input
Enable
output
H
H
H
L
H
L
H
L
z
L
L
z
Table 10:
Truth table of the motor driver
Direction
Input 1
Input 2
Input 3
Input 4
Forward
H
L
L
H
Backward
L
H
H
L
Table 11:
Driver control inputs
chapter 5
5.3
Schematic Explanatio
5.3.1 GPS connections:
5.3.3 MAX-232 connections to microcontroller in is made by using a latch
in between MAX-232 and microcontroller:
CHAPTER 6
6.1 After pressing the reset switch
6.2 While login on fingerprint
1.3While vibration sensor activated
6.6 While sending stop message
CONCLUSION:
REFERENCES:
H-bridge. Sometimes called a "full bridge" the
H-bridge is so named because it has four switching elements at the
"corners" of the H and the motor forms the cross bar.
The key fact to note is that there are, in theory, four
switching elements within the bridge. These four elements are often called,
high side left, high side right, low side right, and low side left (when
traversing in clockwise order).
The switches are turned on in pairs, either high left
and lower right, or lower left and high right, but never both switches on the
same "side" of the bridge. If both switches on one side of a bridge
are turned on it creates a short circuit between the battery plus and battery
minus terminals. If the bridge is sufficiently powerful it will absorb that
load and your batteries will simply drain quickly. Usually however the switches
in question melt.
To power the motor, you turn on two switches that are
diagonally opposed. In the picture to the right, imagine that the high side
left and low side right switches are turned on.
The current flows and the motor begins to turn in a
"positive" direction. Turn on the high side right and low side left
switches, then Current flows the other direction through the motor and the
motor turns in the opposite direction.
One more topic in the basic theory section, quadrants.
If each switch can be controlled independently then you can do some interesting
things with the bridge, some folks call such a bridge a "four quadrant
device" (4QD get it?). If you built it out of a single DPDT relay, you can
really only control forward or reverse. You can build a small truth table that
tells you for each of the switch's states, what the bridge will do. As each
switch has one of two states, and there are four switches, there are 16
possible states. However, since any state that turns both switches on one side
on is "bad" (smoke issues forth: P), there are in fact only four
useful states (the four quadrants) where the transistors are turned on.
High
Side Left
|
High
Side Right
|
Low
Side Left
|
Low
Side Right
|
Quadrant
Description
|
On
|
Off
|
Off
|
On
|
Forward
Running
|
Off
|
On
|
On
|
Off
|
Backward
Running
|
On
|
On
|
Off
|
Off
|
Braking
|
Off
|
Off
|
On
|
On
|
Braking
|
Table
9: H-Bridge truth table
The last two rows describe a maneuver where you
"short circuit" the motor which causes the motors generator effect to
work against itself. The turning motor generates a voltage which tries to force
the motor to turn the opposite direction. This causes the motor to rapidly stop
spinning and is called "braking" on a lot of H-bridge designs. Of
course there is also the state where all the transistors are turned off. In
this case the motor coasts freely if it was spinning and does nothing if it was
doing nothing.
4.12.2
Motor
Driver Connections:
The motor driver requires
2 control inputs for each motor. Since we drive 2 motors, we need 4 controls
Figure 32:
Motor Driver Connections
Inputs from the microcontroller. Since it has many pins which
can be configured as outputs, there are many options for implementation. For
example, in our robot the last 4 bits of Port B (RB4, RB5, RB6,RB7 - Pins 37 to
40) are used to control the rotation direction of the motors . The enable pins
of the motor driver are connected to the PWM outputs of the microcontroller
(Pins 16and 17). This is because, as was mentioned above, by changing the width
of the pulse (implying changing the enable time of the driver) one can change
the speed of the motor. The truth table for motor driver is as shown in Table
10, where H = high, L = low, and Z =high output impedance state.
THE TRUTH TABLE OF THE MOTOR
DRIVER
Input
|
Enable
|
output
|
H
|
H
|
H
|
L
|
H
|
L
|
H
|
L
|
z
|
L
|
L
|
z
|
Table 10:
Truth table of the motor driver
DRIVER CONTROL INPUTS
Direction
|
Input 1
|
Input 2
|
Input 3
|
Input 4
|
Forward
|
H
|
L
|
L
|
H
|
Backward
|
L
|
H
|
H
|
L
|
Table 11:
Driver control inputs
Since the motors are reverse aligned, in order to have the
robot Move forward they must be configured such that one of them turns forward
and the other one turns backward. In case of any requirement for the robot to
move backward, it is sufficient to just reverse the outputs of the control
pins. For example, in our robot while moving forward, inputs of the motor
driver have states shown in the first row Of Table 11, whereas for backward
movement, the states shown in the second row of Table 11 is applied.
chapter 5
ImplEmentation of
interfacing design
5.1 Introduction:
Microcontrollers are
useful to the extent that they communicate with other devices, such as sensors,
motors, switches, keypads, displays, memory and even other micro-controllers. Many
interface methods have been developed over the years to solve the complex
problem of balancing circuit design criteria such as features, cost, size,
weight, power consumption. Many microcontroller designs typically mix multiple interfacing
methods. In a very simplistic form, a micro-controller
system can be viewed as a system that reads from (monitors) inputs, performs
processing and writes to (controls) outputs. Here I am using few interfacing
techniques for design of Fingerprint protected anti theft tracking system. Here
I am using two UART ports for interfacing Fingerprint, GPS and GSM modules
using a latch. Remaining motor, vibration sensor, stop switch, enrolling switch
etc are directly connected to GPIO pins.
5.2 Schematic
Diagram:
5.3.1 GPS connections:
Pins
connections
1. VCC (+5v)
2. This pin is connected to the
T1OUT of the MAX -232 IC
3. This pin is connected to the R1IN
of the MAX -232 IC
4. GND
5. GND
5.3.2 GSM connections:
Pins
connections
1. VCC (+5v)
2. This pin is connected to the
T2OUT of the MAX -232 IC
3. This pin is connected to the
R2IN of the MAX -232 IC
4. GND
5. GND
5.3.3 MAX-232 connections to microcontroller in is made by using a latch
in between MAX-232 and microcontroller:
Pins connections
11 This
pin is connected to P0.0 /TXD0/PWM1 of the Micro controller
12 This
pin is connected to P0.1 /RXD0/PWM3/EINT0
13 This
pin is connected to P0.2/SCL0/CAP0.0
14 This
pin is connected to P0.3/SDA0/MAT0.0/EINT1
15 Ground
16 vcc
5.3.4 LCD connections to Micro controller:
Pins Connections
1 VSS
(ground)
2 VCC
(+5V)
3 10k
pot
4
this pin is connected to P1.16 of the micro controller
6 R/w,
this pin is connected to P1.17 of the micro controller
11-14
these pins are connected through P1.18 to P1.21 of the micro controller
15 this pin is connected to
VCC
16 this pin is connected to GND
5.3.5 Fingerprint connections to the microcontroller:
Pins Connections
VCC VCC_BAR
RX P0.8/TXD1/PWM4/AD1.1
TX P0.9/RXD1/PWM6/EINT3
GND GND
IR Sensor is connected to P1.31/TRST
Vibration sensor is connected to P1.30/TMS
DC motor is connected to P1.29/TCK
CHAPTER 6
RESULTS
6.1 After pressing the reset switch
6.2 While login on fingerprint
1.3While vibration sensor activated
6.4 Enrolling process output
6.5 While sending LOCATION message
6.6 While sending stop message
CONCLUSION:
I strongly believe that the
development of a nation could be done only through progressive development of
all class of people. Hence this vehicle tracking system which not only proves
to be effective but also cheap, would definitely help a great deal in bringing
down expenses ,ensuring the safety of the vehicle be it 2 or 3 or 4 or even
higher wheeled vehicles.
FUTURE SCOPE:
This
system can be developed for car security systems. This a type of biometric
security system gives more security among all other biometrics. This can be
further developed for ATM centers for authentication. This can be developed for
door locking and unlocking security systems. This can be developed for
authentication of any other electronic machine.
REFERENCES:
[1]. Ganesh, Balaji, Varadhan “Anti-Theft Tracking
System for Automobiles” 2011 IEEE Paper
[2]. Islam,
Karhu, Salonen” GPS and GSM antenna
with a capacitive feed for a personal avigator device”-IEEE Paper 2010
[3]. Cai-Cong
Wu, Xiu-Wan Chen, Hong Li, Zhong-Zhong Wu, Ying-Chun Tao”Design
and development of farm vehicle monitoring and intelligent dispatching system”
2004 IEEE paper.
[4]. Qiang Liu;
Huapu Lu; Hongliang Zhang; Bo Zou “Research and Desing of Intelligent Vehicle
Monitoring System Based on GPS/GSM” 2006 IEEE Paper.
[5]. Hindawi, Nader “Performance of differential GPS based on a real-time
algorithm using SMS services of GSM network”
2012 IEEE Paper.
[6]. Peng Chen; Shuang Liu “Intelligent
Vehicle Monitoring System, Based on GPS, GSM and GIS” 2010 IEEE Paper.
[7]. Kaveh
Pahlavan and Prashanth Krishnamurthy, Principles of wireless networks: A
unified approach
1st,” Prentice Hall PTR Upper Saddle River, NJ, USA.2001.
[8]. datasheetarchive.com- For ARM7TDMI-S.
[9]. arm.com- For ARM
[10].
beginnersguide.com
- For GSM.
[11].
howstuffworks.com- For GSM.
[12].
rajguruelectronics.com-Fingerprint
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