ICU Patient Monitoring System With Automatic SMS System Using GSM ZIGBEE Wireless Technology

8/18/2019 ICU Patient Monitoring System With Automatic SMS System Using GSM ZIGBEE Wireless Technology

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BIOMEDICAL SIGNALS MONITORING BASED IN

MOBILE COMPUTING

ABSTRACT:

The main objective of this project consists in the development of a biomedical

instrumentation prototype for acquisition, processing and transmission of biomedical

signals. These biomedical signals are acquired and then processed with a microcontroller.

After processing, all data are sent to a communication interface that can send this

information to a personal computer or a cell phone.

The prototype developed, which is a digital blood pressure meter, is intended to

allow remote monitoring of patients living in areas with limited access to medical

assistance or scarce clinical resources. We believe that this development could be helpful

to improve people’s quality of life, as well as to allow an improvement in the government

attendance indices.

This project uses regulated 5, !5"mA power supply. !#"5 three terminal voltage

regulator is used for voltage regulation. $ridge type full wave rectifier is used to rectify

the ac output of secondary of %&"'(# step down transformer

BLOCK DIAGRAM:

Microcontroller


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POWER SUPPLY:

Heart eet

!en!or

LCD

Te"#erat$re

!en!or

%iration

!en!or

&IGBEE

MA'

()(

%olta*e

re*$lator

+ilterBri,*e

recti-ier

Ste#

,o.n

T/+


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RECEI%ER SECTION:

&IGBEE

Ma0

()(

PC


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SO+TWARE TOOLS:

)mbedded *c’

+eil compiler.

HARDWARE TOOLS:

Atmel based our own developed board

ower supply

-igbee t module

-igbee r module

/cd display

$u00er

1a %&%

2erial communication

3eart beet sensor

temperature sensor

vibration sensor

pc


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INTRODUCTION:

4ver the recent years remote health care monitoring systems for the elderly people

have drawn considerable attentions. According to 67A, the global population is no

longer young for the first time in the history 8(9. opulation ageing is affecting the entire

world and is happening in all regions. $ut, it is progressing at a faster rate in the

developing countries. 2even out of the fifteen countries in the developing world have

more than (" million old people. $y the year %"5" another fifteen developing countries

are epected to have (" million old people.

:t is worthwhile to mention here that the average life epectancy in the nited

2tates was ;!.& years in (


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only incurs epenses, but also incurs loss of patient’s mobility. @emote 3ealth are

1onitoring 2ystem B@312C has been proposed as a solution to this problem. The main

concept is to monitor a patient from a remote location and to provide her'him with

necessary medical advices. The @312 has numerous advantages compared to

conventional healthcare systems. 2ome of the advantages include BaC monitoring a

patient, BbC responding to an emergency, BcC assisting patient mobility, BdC shortening

hospital stay, and BeC reducing medical epenses. $y using @312 the physical

conditions of the patients can be monitored for twenty hours a day and seven days a

wee?. The emergency services can be provided to the patients with a minimum delay. The

patients can be served without going to a health care facility and admitting there. The

healthcare professional can perform the follow up from a remote location and hence a

patient needs to stay in a hospital for a short period of time. :n a nutshell @312 reduces

epenses related to the medical services.

1ost of the proposed @312s are based on wireless technology. The evolution

of the wireless networ? has eperienced a very fast>paced. 2ince the introduction of the

:))) #"%.(( protocol wireless networ?s have eperienced a huge mar?et demand. Within

the four years of the introduction wireless networ?s became very popular because of its

portability, convenience, ease of installation, and low cost 859. :n that time period about

!.5 million households in the nited 2tates deployed wireless networ?. Wireless networ?s

and medical sensors have been combined in @312.

There have been many medical sensors available in the mar?et. 1ost of the sensors can

measure and display critical health monitoring data such as the pulse rate, blood pressure,

temperature, and blood sugar of a patient. 4ne of the limitations of the proposed @312

is its limited coverage area. The measured data cannot be transmitted beyond a certain

distance. Thus, it is not possible for the healthcare professionals to monitor the medical

conditions of a patient from a distant location. :n a hospital either the nurse or the

physician has to move from one patient to another patient for monitoring them. 3ence, it

may not be possible for them to monitor a patient’s health conditions all the time. This

situation can be even worse when they have to ta?e care of a large number of patients in a

hospital at a given time. :n order to overcome the above mentioned limitations an on>line

health monitoring system has been proposed in this wor?. The proposed system can

monitor the temperature, pulse, muscle, and )D data of a patient. The proposed systemhas been designed by using the -ig$ee technology.


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A major portion of this system has been implemented in /abiew. 3ence, the

proposed system is reconfigurable as per users’ need. The proposed system has been

tested and verified in order to ensure its accuracy and reliability. The system consumes a

very low power. The system consumes a very low power because it transmits signal only

if the monitored parameters Bi.e., temperature, heart beat rate etc.C go outside their normal

ranges. 4therwise, the system puts the transmitter into a sleep mode to save energy.

RELATED WORKS

6umerous prototypes for remote health care system can be found in the

literatures. 2ince this wor? is based on the -ig$ee technology, we focus only on the

remote health care systems that have been designed based on the -ig$ee technology. 4ne

of the early wor?s on health care monitoring system has been proposed in 8=9. The

proposed system is suitable for patients, senior citi0ens, and others who need continuous

monitoring of their health.

The proposed system can monitor the )D signals of a patient based on 2ession

:nitiation rotocol B2:C and a -ig$ee networ?. The system consists of a wireless )D

sensor, )D console, -ig$ee module, 2: register, a proy server, a database server, and

wireless devices. 2imultaneous monitoring of the biomedical signals from multiple

patients has been addressed in 8!9. The proposed networ? is based on :))) #"%.(5.;

standard and the -ig$ee technology. The authors have proposed an optimi0ed source

routing protocol to control the networ? load. 2ome other issues including energy

consumption, networ? lifetime, and delivery ratio have also been addressed in the same

wor?. An intelligent remote healthcare system based on power line communication and

the -ig$ee networ? has been proposed in 8#9. The system consists of physiological

sensors, a -ig$ee'/ gateway, and some special software. The physiological data are

collected by the physiological sensor and are sent to a controlling center through a

-ig$ee'/ gateway. The data are stored and analysed at the controlling center. A low

power microcontroller based patient bed monitoring system has been presented in 8


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collected by the access point is transferred to a hospital networ? over mobile

communication networ?. The authors have proposed a novel Ewa?e>up on>demandF mode

of networ? operation. According to this mode the networ? EsleepsF when the most of the

circuits are turned off to reduce power consumption. 4nce the W$A26 is wa?ed up all

modules begin to wor? and all biomedical signals are obtained, stored, and transmitted.

@eliability of data transmission for healthcare monitoring system has been investigated in

8((9.

The authors have suggested that there is always a chance for loosing physiological

data when a :nternational Gournal of Wireless H 1obile 6etwor?s B:GW16C ol. =, 6o.

&, Gune %"(; 5= number of -ig$ee devices operate in a hospital at a given time. Although

the medium access control is ta?en care of by the 1A layer, the authors have designedand implemented a new medium access control algorithm to ensure reliable data

transmission of the physiological data. A telemedicine information monitoring system

consists of vital sign monitoring devices, a healthcare gateway, and a health service

information platform has been proposed in 8(%9. Among these components the healthcare

gateway is the most critical component. The -ig$ee module is used to transmit

information between the vital sign monitoring devices and the healthcare gateway. The

vital sign monitoring devices include )D, 24%, blood pressure, glucose, and body

temperature. The data is then relayed to a healthcare service information platform. The

system is based on 2ervice 4riented Architecture B24AC concept to provide the healthcare

management for people who are suffering from chronic illness. A remote patient

monitoring system based on the -ig$ee wireless sensor networ? and the :nternet Things

has been introduced in 8(&9. The system generates electronic medical records that are

saved in a database. After analysing the data the proposed system can send feedbac?

about the diagnosis, medical programs, and proposals to a remote location. The system

uses the -ig$ee networ? for real time transmission of the physical data. The data

processing and information releasing have been implemented by a database program. A

wearable remote healthcare system for assessing hydration status and visceral fat

accumulation by using $ioelectrical :mpedance B$:C analysis has been proposed in 8(;9.

The authors have designed a -ig$ee based $: to replace the conventional wired $:. The

proposed system consists of $: measurement circuit integrated with ".&5 Im 142

technology and a transducer circuit of the -ig$ee module.

Two alternative systems have been proposed for the deployment of the -ig$ee


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general wards of a hospital in 8(59. :n the first approach a single WA6 is considered for

gathering and transmitting physiological data from the patients in a ward. :n the second

approach multiple WA62 are considered. The simulation results show that the multiple

WA62 out>perform the single one in respect of efficiency and reliability for data

transmission. An epandable wireless health monitoring system based on -ig$ee has

been proposed in 8(=9. The proposed system can monitor the temperature and pulses of a

patient wirelessly. The test result presented therein shows that the proposed system can

monitor the temperature and pulse of a patient with a high accuracy. An ambient care

system BA2C framewor? to provide remote monitoring, emergency detection, activity

logging, and personal notification services has been proposed in 8(!9.

The proposed system consists of rossbow 1:A- devices, sensors, and JAenabled with -ig$ee technology. The authors concluded that the combination of the

-ig$ee technology together with a service oriented architecture is the best option for A2

services. A wireless sensor gateway BW2DC has been proposed in 8(#9 to monitor patients’

health. The main objective of this project is to monitor the cardiovascular status of a

patient. $iological signals li?e )D, pulse wave, and body weight are the important

parameters for the cardiovascular monitoring of a patient. The proposed gateway is

deigned to receive data from wireless sensors through a -ig$ee interface and to forward

the same to a personal computer via $luetooth interface. A -ig$ee based system for

remote monitoring of 24% has been proposed in 8(ordinators. All

:nternational Gournal of Wireless H 1obile 6etwor?s B:GW16C ol. =, 6o. &, Gune %"(;

5! the devices are based on 1 and -ig$ee chip. The sensor devices measure 24%

data from patients and transmit the data to the router. The router sets schedule for data

transmission to each device by using a hierarchical routing. The proposed system also

contains a web>based management system so that the patient data can be published in the

web. A real>time rehabilitation platform for patients and aged people has been proposed in

8%"9. The proposed system can collect data about the real>time wal?ing acceleration of the

patients. $y analysing the gait sequences the computer based rehabilitation system can

figure out the normal gait and abrupt falling of the people. The system also includes an

)D detector to monitor the health condition of the patients and the aged people. A

prototype of smart sniffing shoes has been designed for monitoring the foot health of a

patient in 8%(9.


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The proposed system consists of chemical sensor array installed inside the shoe.

The -ig$ee technology has been used for the data communication. A technique called

principal component analysis BAC has been used to monitor the foot health of a patient.

Another -ig$ee based health monitoring system has been proposed to monitor

temperature, heart rate, blood pressure, and movements of patients in 8%%9. The main

component of the system is an electronic device worn on the wrist or finger of a high ris?

patient. The system uses a number of sensors including an impact sensor to detect the fall

of a person. The system can monitor a medically distressed person and send an alarm to a

careta?er system connected to a remote computer. A similar wor? for monitoring the

patient’s pulse has been presented in 8%&9. The proposed system can monitor the pulses of

a patient from a remote location and it can also administer necessary medical treatment.

The proposed system consists of a pulse sensor, -ig$ee module, and ATmega%(#

microcontroller. The pulse measured by the sensor is sent to a coordinator through a

-ig$ee interface. The test results show that the proposed system can cover up to &" meter

distance. A prototype model for cardiovascular activity and fitness monitoring system

based on :))) (("!& family has been proposed in 8%;9. The :))) (("!&>(";;( defines

the set of protocols for tele>health environment at application layer and the rest of the

communication is ta?en care of by the medical grade -ig$ee networ?. The test results

show that the proposed system can report severe cardiovascular malfunctioning without

compromising the mobility. A remote heart sound and lung sound monitoring system has

been proposed in 8%59. The authors have solved the problem related to simultaneous

transmission of heart and lung sounds. 2ensors have been used to collect the heart and

lung sounds and then 7ast:A is used to separate these two signals. The sound signals are

then sent to a remote location via internet for diagnosis. A low cost sleep monitoring

system based on polysomnography has been proposed in 8%=9. The authors have

introduced some innovative sensor pillow and bed sheet system that employ the -ig$ee

wireless networ?. To monitor the respiration of the patient a sensor array of force

sensitive resistors B72@C based on polymer thic? film device has been used. The sensor

array is able to classify and verify the respiratory rate during sleep. A portable )D

monitoring system has been proposed in 8%!9.

The proposed system is controlled by 12;&" single chip computer, which

amplifies and filters the patient’s )D signals and sends data to a central controller usinga -ig$ee wireless transmission module. Another similar prototype of a -ig$ee based


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Wireless H 1obile 6etwor?s B:GW16C ol. =, 6o. &, Gune %"(; 5# based D: interface

has been developed to provide )D signal processing tas? and health care video trac?ing

and management functions. :n this wor? we have proposed a remote health monitoring

system based on the -ig$ee technology and /abiew software. The proposed system can

monitor )D signals, muscle power, temperature, and heartbeat of a patient from a

remote location. :n contrast to other related wor?s we used 6ational :nstruments’

/abiew software for implementing the project. The /abiew constitutes a graphical

programming environment that can acquire data Bi.e., biomedical signalsC. The /abiew

relies on graphical symbols rather than tetual language to describe programming actions.

The principle of dataflow governs program eecution in a straightforward manner. We

chose /abiew software because it is easy to program and it has powerful data

acquisition system. :n addition the output data generated by the /abiew program can be

easily acquired into hardware. The data acquisition is performed by using Jata

Acquisition 2ystem BJAKC provided by the 6ational :nstrument. The use of JAK

reduces the compleities of the circuits. 2ince the major portion of this wor? is

implemented in /abiew, the proposed system can be easily reconfigured and adapted to

accommodate more options in future. The system can send data to a remote location for

diagnosis. The system can also publish data in the internet so that the concerned

healthcare professionals can monitor their patients from anywhere around the World at

any time.

O%ER%IEW O+ EMBEDDED SYSTEM ARCHITECTURE

)very embedded system consists of custom>built hardware built around a entral

rocessing nit BC. This hardware also contains memory chips onto which the software is

loaded. The software residing on the memory chip is also called the *firmware’. The embedded

system architecture can be represented as a layered architecture as shown in 7ig.

The operating system runs above the hardware, and the application software runs above

the operating system. The same architecture is applicable to any computer including a des?top

computer. 3owever, there are significant differences. :t is not compulsory to have an operating

system in every embedded system. 7or small appliances such as remote control units, air

conditioners, toys etc., there is no need for an operating system and you can write only the

software specific to that application. 7or applications involving comple processing, it is

advisable to have an operating system. :n such a case, you need to integrate the application

software with the operating system and then transfer the entire software on to the memory chip.

4nce the software is transferred to the memory chip, the software will continue to run for a long


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6ow, let us see the details of the various building bloc?s of the hardware of an embedded

system. As shown in 7ig. the building bloc?s areL

M entral rocessing nit BC

M 1emory B@ead>only 1emory and @andom Access 1emoryC

M :nput Jevices

M 4utput devices

M ommunication interfaces

M Application>specific circuitry

Central Proce!!in* Unit 1CPU2:

The entral rocessing nit Bprocessor, in shortC can be any of the followingN

microcontroller, microprocessor or Jigital 2ignal rocessor BJ2C. A micro>controller is a low>

cost processor. :ts main attraction is that on the chip itself, there will be many other components

such as memory, serial communication interface, analog>to digital converter etc. 2o, for small

applications, a micro>controller is the best choice as the number of eternal components required

will be very less. 4n the other hand, microprocessors are more powerful, but you need to use


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many eternal components with them. J5 is used mainly for applications in which signal

processing is involved such as audio and video processing.

Me"or3:

The memory is categori0ed as @andom Access ((emory B@A1C and @ead 4nly 1emory

B@41C. The contents of the @A1 will be erased if power is switched off to the chip, whereas

@41 retains the contents even if the power is switched off. 2o, the firmware is stored in the

@41. When power is switched on, the processor reads the @41L the program is program is

eecuted.

In#$t ,e4ice!:

nli?e the des?tops, the input devices to an embedded system have very limited

capability. There will be no ?eyboard or a mouse, and hence interacting with the embedded

system is no easy tas?. 1any embedded systems will have a small ?eypad>you press one ?ey to

give a specific command. A ?eypad may be used to input only the digits. 1any embedded

systems used in process control do not have any input device for user interactionL they ta?e inputs

from sensors or transducers (’fnd produce electrical signals that are in turn fed to other systems.

O$t#$t ,e4ice!:

The output devices of the embedded systems also have very limited capability. 2ome

embedded systems will have a few /ight )mitting Jiodes B/)JsC to indicate the health status of

the system modules, or for visual indication of alarms. A small /iquid rystal Jisplay B/JC may

also be used to display some important parameters.

Co""$nication inter-ace!:

The embedded systems may need to, interact with other embedded systems at they may

have to transmit data to a des?top. To facilitate this, the embedded systems are provided with one

or a few communication interfaces such as @2%&%, @2;%%, @2;#5, niversal 2erial $us B2$C,

:))) (&


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omputer networ?ing products such as bridges, routers, :ntegrated 2ervices Jigital

6etwor?s B:2J6C, Asynchronous Transfer 1ode BAT1C, O.%5 and frame relay switches are

embedded systems which implement the necessary data communication protocols. 7or eample, a

router interconnects two networ?s. The two networ?s may be running different protocol stac?s.

The router’s function is to obtain the data pac?ets from incoming pores, analy0e the pac?ets and

send them towards the destination after doing necessary protocol conversion. 1ost networ?ing

equipments, other than the end systems Bdes?top computersC we use to access the networ?s, are

embedded systems

Teleco""$nication!:

:n the field of telecommunications, the embedded systems can be categori0ed as

subscriber terminals and networ? equipment. The subscriber terminals such as ?ey telephones,

:2J6 phones, terminal adapters, web cameras are embedded systems. The networ? equipment

includes multipleers, multiple access systems, ac?et Assemblers Jissemblers BAJsC, sate((ite

modems etc. : phone, : gateway, : gate?eeper etc. are the latest embedded systems that

provide very low>cost voice communication over the :nternet.

Wirele!! tec7nolo*ie!:

Advances in mobile communications are paving way for many interesting applications

using embedded systems. The mobile phone is one of the marvels of the last decade of the %"’h

century. :t is a very powerful embedded system that provides voice communication while we are

on the move. The ersonal Jigital Assistants and the palmtops can now be used to access

multimedia services over the :nternet. 1obile communication infrastructure such as base station

controllers, mobile switching centers are also powerful embedded systems.

In!e"ination:

Testing and measurement are the fundamental requirements in all scientific and

engineering activities. The measuring equipment we use in laboratories to measure parameterssuch as weight, temperature, pressure, humidity, voltage, current etc. are all embedded systems.

Test equipment such as oscilloscope, spectrum analy0er, logic analy0er, protocol analy0er, radio

communication test set etc. are embedded systems built around powerful processors. Than? to

miniaturi0ation, the test and measuring equipment are now becoming portable facilitating easy

testing and measurement in the field by field>personnel.

Sec$rit3:

2ecurity of persons and information has always been a major issue. We need to protect

our homes and officesL and also the information we transmit and store. Jeveloping embedded


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devices at homes, offices, airports etc. for authentication and verification are embedded systems.

)ncryption devices are nearly controller and memoryL and it

interacts with the smart card readerQ AT1 machine and acts as an electronic wallet. 2mart card

technology has the capability of ushering in a cashless society. Well, the list goes on. :t is no

eaggeration to say that eyes wherever you go, you can see, or at least feel, the wor? of an

embedded system.

)mbedded systems find applications in every industrial segment> consumer electronics,

transportation, avionics, biomedical engineering, manufacturing, process control and industrial

automation, data communication, telecommunication, defense, security etc. sed to encrypt the

data'voice being transmitted on communication lin?s such as telephone lines. $iometric systems

using fingerprint and face recognition are now being etensively used for user authentication in

ban?ing applications as well as for access control in high security buildings.

MICROCONTROLLERS

A microcontroller Bsometimes abbreviated I, u or 1C is a small computer

on a single integrated circuit containing a processor core, memory, and programmable

input'output peripherals. rogram memory in the form of 64@ flash or 4T @41 is also

often included on chip, as well as a typically small amount of @A1. 1icrocontrollers are

designed for embedded applications, in contrast to the microprocessors used in personal

computers or other general purpose applications.

1icrocontrollers are used in automatically controlled products and devices, such

as automobile engine control systems, implantable medical devices, remote controls,

office machines, appliances, power tools, toys and other embedded systems. $y reducing

the si0e and cost compared to a design that uses a separate microprocessor, memory, and

input'output devices, microcontrollers ma?e it economical to digitally control even more

devices and processes. 1ied signal microcontrollers are common, integrating analog

components needed to control non>digital electronic systems.

2ome microcontrollers may use four bit words and operate at cloc? rate

http://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/Flash_memory#NOR_flashhttp://en.wikipedia.org/wiki/Programmable_read-only_memoryhttp://en.wikipedia.org/wiki/Random-access_memoryhttp://en.wikipedia.org/wiki/Microprocessorhttp://en.wikipedia.org/wiki/Microprocessorhttp://en.wikipedia.org/wiki/Personal_computerhttp://en.wikipedia.org/wiki/Personal_computerhttp://en.wikipedia.org/wiki/Embedded_systemhttp://en.wikipedia.org/wiki/Embedded_systemhttp://en.wikipedia.org/wiki/Mixed-signal_integrated_circuithttp://en.wikipedia.org/wiki/Word_(computer_architecture)http://en.wikipedia.org/wiki/Clock_ratehttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/Flash_memory#NOR_flashhttp://en.wikipedia.org/wiki/Programmable_read-only_memoryhttp://en.wikipedia.org/wiki/Random-access_memoryhttp://en.wikipedia.org/wiki/Microprocessorhttp://en.wikipedia.org/wiki/Personal_computerhttp://en.wikipedia.org/wiki/Personal_computerhttp://en.wikipedia.org/wiki/Embedded_systemhttp://en.wikipedia.org/wiki/Mixed-signal_integrated_circuithttp://en.wikipedia.org/wiki/Word_(computer_architecture)http://en.wikipedia.org/wiki/Clock_ratehttp://en.wikipedia.org/wiki/Integrated_circuit


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They will generally have the ability to retain functionality while waiting for an event such

as a button press or other interruptL power consumption while sleeping B cloc? and

most peripherals offC may be just nano watts, ma?ing many of them well suited for long

lasting battery applications. 4ther microcontrollers may serve performance>critical roles,

where they may need to act more li?e a digital signal processor BJ2C, with higher cloc?

speeds and power consumption.

1any embedded systems need to read sensors that produce analog signals. This is

the purpose of the analog>to>digital converter BAJC. 2ince processors are built to

interpret and process digital data, i.e. (s and "s, they are not able to do anything with the

analog signals that may be sent to it by a device. 2o the analog to digital converter is used

to convert the incoming data into a form that the processor can recogni0e. A less common

feature on some microcontrollers is a digital>to>analog converter BJAC that allows the

processor to output analog signals or voltage levels.

http://en.wikipedia.org/wiki/Digital_signal_processorhttp://en.wikipedia.org/wiki/Digital_signal_processorhttp://en.wikipedia.org/wiki/Analog-to-digital_converterhttp://en.wikipedia.org/wiki/Digital-to-analog_converterhttp://en.wikipedia.org/wiki/Digital_signal_processorhttp://en.wikipedia.org/wiki/Analog-to-digital_converterhttp://en.wikipedia.org/wiki/Digital-to-analog_converter


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7igN Architecture of 1icrocontroller

AT89C(

The AT#power, high>performance 142 #>bit microcomputer with

#?bytes of 7lash programmable and erasable read only memory B)@41C. The device is

manufactured using Atmel’s high>density nonvolatile memory technology and is

ibl i h h i d d d #" ( d #" % i i d i h


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conventional nonvolatile memory programmer by combining a versatile #>bit with

7lash on a monolithic chip. The Atmel AT#fleible and cost>effective solution to many embedded control

applications. The AT#power, high>performance 142 #>bit

microcomputer with #? bytes of 7lash programmable and erasable read only memory

B)@41C.

+eat$re!

R ompatible with 12>5( roducts

R #+ $ytes of :n>2ystem @eprogrammable 7lash 1emory

R )nduranceN (,""" Write')rase ycles

R 7ully 2tatic 4perationN " 30 to %; 130

R Three>level rogram 1emory /oc?

R %5= #>bit :nternal @A1

R &% rogrammable :'4 /ines

R Three (=>bit Timer'ounters

R )ight :nterrupt 2ources

R rogrammable 2erial hannel

R /ow>power :dle and ower>down 1odes

R 7ive vector two>level interrupt architecture

R A full duple serial port

R 2i :nterrupt 2ources

R 4n>chip oscillator and cloc? circuitry

BLOCK DIAGRAM:


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PIN DIAGRAM


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7igN :6 Jiagram

PIN DESCRIPTION

PINS ;58 PORT ;:

)ach of these pins can be configured as input or output.

PIN 9 < RST

/ogical one on this pin stops microcontroller’s operating and erases the contents of most

registers. $y applying logical 0ero to this pin, the program starts eecution from the

beginning. :n other words, a positive voltage pulse on this pin resets the microcontroller.

PINS ;=5;> PORT ):2imilar to port (, each of these pins can serve as universal input or

output. $esides, all of them have alternative functionsN

Pin ;=: R'D

2erial asynchronous communication input or 2erial synchronous communication output.

Pin ;;: T'D

2erial asynchronous communication output or 2erial synchronous communication cloc?

output.


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:nterrupt " inputs

Pin ;): INT;

:nterrupt ( input

Pin ;?: T=

ounter " cloc? input

Pin ;: T;

ounter ( cloc? input

Pin ;@: WR

2ignal for writing to eternal BadditionalC @A1

Pin ;>: RD

2ignal for reading from eternal @A1

Pin ;8 ;9: '( ';

:nternal oscillator input and output. A quart0 crystal which determines operating

frequency is usually connected to these pins. :nstead of quart0 crystal, the miniature ceramics

resonators can be also used for frequency stabili0ation. /ater versions of the microcontrollers

operate at a frequency of " 30 up to over 5" 30.

'TAL;

:nput to the inverting oscillator amplifier and input to the internal cloc? operating circuit.

'TAL(

4utput from the inverting oscillator amplifier.

O!cillator C7aracteri!tic!

OTA/( and OTA/% are the input and output, respectively, of an inverting amplifier which can be configured for use as an on>chip oscillator, as shown in 7igure (. )ither a quart0


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To drive the device from an eternal cloc? source, OTA/% should be left unconnected while

OTA/( is driven as shown in 7igure %. There are no requirements on the duty cycle of the

eternal cloc? signal, since the input to the internal cloc?ing circuitry is through a divide>by>two

flip>flop, but minimum and maimum voltage high and low time specifications must be observed.

42://AT4@ 466)T:462

Pin (=: GND

2ignal Dround

PINS (;5(8 PORT (:

:f there is no intention to use eternal memory then these port pins are configured


24/85

i.e. addresses A#>A(5 will appear on this port. :t is important to ?now that even memory

with capacity of =;+b is not used B i.e. note all bits on port are used for memory

addressingC the rest of bits are not available as inputs or outputs.

Pin (9: PSEN

rogram 2tore )nable is the read strobe to eternal program memory. When the

AT#"

value every time the microcontroller reads a byte from memory.

Pin )=: ALE

rior to each reading from eternal memory, the microcontroller will set the lower

address byte BA">A!C on " and immediately after that activates the output A/). pon receiving

signal from the A/) pin, the eternal register B!;3T&!& or !;3T&!5 circuit is usually

embeddedC memori0es the state of " and uses it as an address for memory chip. :n the second

part of the microcontroller’s machine cycle, a signal on this pin stops being emitted and " is used

now for data transmission BJata $usC. :n this way, by means of only one additional Band cheapC

integrated circuit, data multipleing from the port is performed. This port at the same time used

for data and address transmission.

Address /atch )nable output pulse for latching the low byte of the address during

accesses to eternal memory. This pin is also the program pulse input B@4DC during 7lash

programming. :n normal operation A/) is emitted at a constant rate of ('= the oscillator

frequency, and may be used for eternal timing or cloc?ing purposes. 6ote, however, that one

A/) pulse is s?ipped during each access to eternal Jata 1emory. :f desired, A/) operation can

be disabled by setting bit " of 27@ location #)3. With the bit set, A/) is active only during a

14O or 14 instruction. 4therwise, the pin is wea?ly pulled high. 2etting the A/)>disable

bit has no effect if the microcontroller is in eternal eecution mode.

PIN ); EA/%PP:

)ternal Access )nable must be strapped to D6J in order to enable the device to

fetch code from eternal program memory locations starting at """"3 up to 77773.

6ote, however, that if loc? bit ( is programmed, EA will be internally latched on reset.


25/85


26/85

always remember that the register ban?s really reside in the first &% bytes of :nternal

@A1.

Ba!ic Re*i!ter!

T7e Acc$"$lator:

The Accumulator, as it’s name suggests, is used as a general register to

accumulate the results of a large number of instructions. :t can hold an #>bit B(>byteC

value and is the most versatile register the #


27/85

TIMERS:

The #"5% has two timersN Timer ", Timer (and Timer %. They can be used either as timers

to generate a time delay or as counters to count events happening outside the

microcontroller. Three timers are (=>bit wide. 2ince the #"5% has an #>bit architecture,

each (= bit timer is accessed as two separate registers of low byte and high byte The


28/85

higher byte is T3". 2imilarly lower byte register of Timer( is T/( and higher byte

register is T3(.

TMOD 1ti"er "o,e2 re*i!ter:

$oth timers " and ( use the same register T14J to set the various operation

modes. T14J is an #>bit register in which the lower ; bits are set aside for Timer " and

the upper ; bits for Timer (. :n each case, the lower % bits are used to set the timer mode

and the upper % bits to specify the operation.

B12$C B/2$C

DAT)

)very timer has a means of starting and stopping. 2ome timers do this by software, some

by hardware and some have both software and hardware controls. The timers in the #"5(

have both. The start and stop of the timer are controlled by the way of software by the T@

Btimer startC bits T@" and T@(. These instructions start and stop the timers as long as

DAT)U" in the T14J register. The hardware way of starting and stopping the timer by

an eternal source is achieved by ma?ing DAT)U( in the T14J register.

'TN

Timer or counter selected. leared for timer operation and set for counter operation.

1(

1ode bit (

1"

1ode bit "

DAT) 'T 1( 1" DAT) 'T 1(

1"


29/85

" " " (&>bit timer mode

#>bit timer'counter T3 with T/ as 5>bit prescaler

" ( ( (=>bit timer mode

(=>bit timer'counters T3 and T/ are cascaded

( " % #>bit auto reload timer'counter

T3 holds a value that is to be reloaded into T/ each time

it overflows

( ( & 2plit timer mode

The mode used here to generate a time delay is 14J) %.

This mode % is an #>bit timer and therefore it allows only values of ""3 to 773 to

be loaded into the timer’s register T3. After T3 is loaded with the #>bit value, the #"5(

give a copy of it to T/. When the timer starts, it starts to count up by incrementing the T/

register. :t counts up until it reaches its limit of 773. When it rolls over from 773 to ""3,

it sets high the T7 Btimer flagC. :f Timer " is used, T7" goes high and if Timer ( is used,

T7( goes high. When the T/ register rolls from 773 to " and T7 is set to (, T/ is

reloaded automatically with the original value ?ept by the T3 register.

Ti"er (

Timer % is a (=>bit Timer'ounter that can operate as either a timer or an event counter.

The type of operation is selected by bit 'T% in the 27@ T%46 Bshown in Table %C. Timer % has

three operating modesN capture, auto>reload Bup or down countingC, and baud rate generator. The

modes are selected by bits in T%46, as shown in Table &. Timer % consists of two #>bit registers,

T3% and T/%. :n the Timer function, the T/% register is incremented every machine cycle. 2ince

a machine cycle consists of (% oscillator periods, the count rate is ('(% of the oscillator frequency.


30/85

:n the ounter function, the register is incremented in response to a (>to>" transition at its

corresponding eternal input pin, T%. :n this function, the eternal input is sampled during 25%

of every machine cycle. When the samples show a high in one cycle and a low in the net cycle,

the count is incremented. The new count value appears in the register during 2&( of the cycle

following the one in which the transition was detected. 2ince two machine cycles B%; oscillator

periodsC are required to recogni0e a (>to>" transition, the maimum count rate is ('%; of the

oscillator frequency. To ensure that a given level is sampled at least once before it changes, the

level should be held for at least one full machine cycle.

Timer % @egisters ontrol and status bits are contained in registers T%46 Bshown in

Table %C and T%14J Bshown in Table ;C for Timer %. The register pair B@A%3, @A%/C are

the apture'@eload registers for Timer % in (=>bit capture mode or (=>bit auto>reload mode.

T7%N

Timer % overflow flag set by a Timer % overflow and must be cleared by software. T7% will not be

set when either @/+ U ( or T/+ U (.

)O7%N

Timer % eternal flag set when either a capture or reload is caused by a negative transition on

T%)O and )O)6% U (. When Timer % interrupt is enabled, )O7% U ( will cause the to

vector to the Timer % interrupt routine. )O7% must be cleared by software. )O7% does not cause

an interrupt in up'down counter mode BJ)6 U (C.


31/85

@/+N @eceive cloc? enable. When set, causes the serial port to use Timer % overflow pulses for

its receive cloc? in serial port 1odes ( and &. @/+ U " causes Timer ( overflow to be used for

the receive cloc?.

T/+N

Transmit cloc? enable. When set, causes the serial port to use Timer % overflow pulses for its

transmit cloc? in serial port 1odes ( and &. T/+ U " causes Timer ( overflows to be used for

the transmit cloc?.

)O)6%N

Timer % eternal enable. When set, allows a capture or reload to occur as a result of a

negative transition on T%)O if Timer % is not being used to cloc? the serial port. )O)6% U "

causes Timer % to ignore events at T%)O.

T@%N

2tart'2top control for Timer %. T@% U ( starts the timer.

'T%N Timer or counter select for Timer %. 'T% U " for timer function. 'T% U ( for eternal

event counter Bfalling edge triggeredC.

'@/%N

apture'@eload select. '@/% U ( causes captures to occur on negative transitions at

T%)O if )O)6% U (. '@/%U " causes automatic reloads to occur when Timer % overflows or

negative transitions occur at T%)O when )O)6%U (. When either @/+ or T/+ U (, this bit is

ignored and the timer is forced to auto>reload on Timer % overflow.

:nterrupt @egisters N The individual interrupt enable bits are in the :) register. Two priorities can

be set for each of the si interrupt sources in the : register.

T7e Data Pointer 1DPTR2:

The Jata ointer BJT@C is the #accessible (=>bit B%>byteC

register. The Accumulator, S@S registers, and S$S register are all (>byte values. JT@, as

the name suggests, is used to point to data. :t is used by a number of commands which

allow the #


32/85

T7e Pro*ra" Co$nter 1PC2:

The rogram ounter BC is a %>byte address which tells the #

byteC value. The 2tac? ointer is used to indicate where the net value to be removed from the

stac? should be ta?en from. When you push a value onto the stac?, the #


33/85

:nput'4utputN

This is a simplified overview of what is connected to a pin inside the microcontroller. :t

concerns

all pins ecept those included in " which do not have embedded pull>up resistor.


34/85

4utput pinN

A logic 0ero B"C is applied to a bit in the register. $y turning output 7) transistor on, the

appropriate pin is directly connected to ground.

In#$t Pin:

/ogic one B(C is applied to a bit in the register. 4utput 7) transistor is turned off. The

appropriate pin remains connected to voltage power supply through a pull>up resistor of

high resistance .


35/85

A logic state BvoltageC on any pin can be changed or read at any moment. A logic 0ero B"C

and logic one B(C are not equal. A logic one B"C represents almost short circuit to ground.

2uch a pin is configured as output.

A logic one B(C is ElooselyF connected to voltage power supply through resistors of high

resistance. 2ince this voltage can be easily Epulled downF by an eternal signal, such a pin is

configured as input.

Port =

ort " is an #>bit open>drain bi>directional :'4 port. As an output port, each pin can sin?

eight TT/ inputs. When (s are written to port " pins, the pins can be used as high impedance

inputs. ort " may also be configured to be the multipleed low order address'data bus during

accesses to eternal program and data memory. :n this mode " has internal pull>ups. ort " also

receives the code bytes during 7lash programming, and outputs the code bytes during program

verification. )ternal pull>ups are required during program verification.

:t is specific to this port to have a double purpose. :f eternal memory is used then

the lower address byte Baddresses A">A!C is applied on it. 4therwise, all bits on this port

are configured as inputs or outputs.

Another characteristic is epressed when it is configured as output. 6amely,

unli?e other ports consisting of pins with embedded pull>up resistor B connected by its end

to 5 power supply C this resistor is left out here This apparently little change has its


36/85

:f any pin on this port is configured as input then it performs as if it EfloatsF. 2uch input

has unlimited input resistance and has no voltage coming from EinsideF.

When the pin is configured as output, it performs as Eopen drainF, meaning that by

writing " to some port’s bit, the appropriate pin will be connected to ground B"C. $y

writing (, the eternal output will ?eep on EfloatingF. :n order to apply ( B5C on this


37/85

4nly in case " is used for addressing eternal memory B only in that caseC, the

microcontroller will provide internal power supply source in order to establish logical ones on

pins. There is no need to add eternal pullup resistors.

Port ;

ort ( is an #>bit bi>directional :'4 port with internal pull>ups. The ort ( output buffers

can sin?'source four TT/ inputs. When (s are written to ort ( pins they are pulled high by the

internal pull>ups and can be used as inputs. As inputs, ort ( pins that are eternally being pulled

low will source current B::/C because of the internal pull>ups. ort ( also receives the low>order

address bytes during 7lash programming and verification.

This is a true :'4 port, because there are no role assigning as it is the case with ".

2ince it has embedded pull>up resistors it is completely compatible with TT/ circuits.

Port (

2imilar to ", when using eternal memory, lines on this port occupy addresses intended

for eternal memory chip. This time it is the higher address byte with addresses A#>A(5. When

there is no additional memory, this port can be used as universal input>output port similar by its

features to the port (. ort % is an #>bit bi>directional :'4 port with internal pull>ups.

The ort % output buffers can sin?'source four TT/ inputs. When (s are written to ort % pins they

are pulled high by the internal pull>ups and can be used as inputs. As inputs, ort % pins that are eternally

being pulled low will source current B::/C because of the internal pull>ups. ort % emits the high>order

address byte during fetches from eternal program memory and during accesses to eternal data (=>bit

addresses B14OVJT@C. :n this application, it uses strong memory uses internal pull>ups when

emitting(s. Juring accesses to eternal data memory that uses #>bit addresses B14O V @:CL ort % emits

the contents of the % 2pecial 7unction @egister. ort%also receives the high>order address bits and some

control signals during 7lash programming and verification.

Port )

)ven though all pins on this port can be used as universal :'4 port, they also have an

alternative function. 2ince each of these functions use inputs, then the appropriate pins have to be

configured li?e that. :n other words, prior to using some of reserve port functions, a logical one

B(C must be written to the appropriate bit in the & register. 7rom hardware’s perspective, this port

is also similar to ", with the difference that its outputs have a pull>up resistor embedded. ort &

is an #>bit bi>directional :'4 port with internal pull>ups. The ort & output buffers can sin?'source

four TT/ inputs. When (s are written to ort & pins they are pulled high by the internal pull>ups

mailto:MOVX@DPTR).Inthismailto:MOVX@DPTR).Inthismailto:MOVX@DPTR).Inthis


38/85

current B::/C because of the pull>ups. ort & also serves the functions of various special features of

the AT#


39/85

should have in mind that pull>up resistors have a relatively high resistance. onsequently

it can be counted on only several hundred microamperes of current coming out of a pin.

MICROCONTROLLER MEMORY ORGANI&ATION

The microcontroller memory is divided into rogram 1emory and Jata 1emory.

rogram 1emory B@41C is used for permanent saving program being eecuted, while

Jata 1emory B@A1C is used for temporarily storing and ?eeping intermediate results and

variables. Jepending on the model in use at most a few +b of @41 and (%# or %5= bytes

of @A1 can be used howeverX

All #"5( microcontrollers have (=>bit addressing bus and can address =; ?b

memory. :t is neither a mista?e nor a big ambition of engineers who were wor?ing on

basic core development. :t is a matter of very clever memory organi0ation which ma?es

these controllers a real Eprogrammers’ tidbitF.

Pro*ra" Me"or3

The oldest models of the #"5( microcontroller family did not have internal

program memory. :t was added from outside as a separate chip. These models are

recogni0able by their label beginning with #"& Bfor e. #"&( or #"&%C. All later modelshave a few +bytes @41 embedded, )ven though it is enough for writing most of the

programs, there are situations when additional memory is necessary. A typical eample of

it is the use of so called loo?up tables. They are used in cases when something is

too complicated or when there is no time for solving equations describing some process.

The eample of it can be totally eotic Ban estimate of self>guided roc?ets’ meeting pointC

or totally common Bmeasuring of temperature using non>linear thermo element or

asynchronous motor speed controlC. :n those cases all needed estimates and approimates

are eecuted in advance and the final results are put in the tables Bsimilar to logarithmic

tablesC.

3ow does the microcontroller handle eternal memory depend on the pin )A logic stateY


40/85


41/85

counters and timers, input'output ports, serial data buffers etc. The previous versions have

the total memory si0e of %5= locations, while for later models this number is incremented

by additional (%# available registers. :n both cases, these first %5= memory locations

Baddresses ">77hC are the base of the memory. ommon to all types of the #"5(

microcontrollers. /ocations available to the user occupy memory space with addresses

from " to !7h. 7irst (%# registers and this part of @A1 is divided in several bloc?s.

The AT#chip @A1. The upper (%# bytes occupy a

parallel address space to the 2pecial 7unction @egisters. That means the upper (%# bytes have the

same addresses as the 27@ space but are physically separate from 27@ space. When an instruction

accesses an internal location above address !73, the address mode used in the instruction

specifies whether the accesses the upper (%# bytes of @A1 or the 27@ space. :nstructions

that use direct addressing access 27@ space. 7or eample, the following direct addressing

instruction accesses the 27@ at location "A"3 Bwhich is %C.

14 "A"3, Zdata

:nstructions that use indirect addressing access the upper (%# bytes of @A1. 7or eample, the

following indirect addressing instruction, where @" contains "A"3, accesses the data byte at

address "A"3, rather than % Bwhose address is "A"3C.

14 V@", Zdata

6ote that stac? operations are eamples of indirect addressing, so the upper (%# bytes of data

@A1 are available as stac? space.

A,,itional Me"or3 Bloc6 o- Data Me"or3

:n order to satisfy the programmers’ permanent hunger for Jata 1emory,

producers have embedded an additional memory bloc? of (%# locations into the latest

versions of the #"5( microcontrollers. 6aturally, it’s not so simpleXThe problem is that

electronics performing addressing has ( byte B# bitsC on disposal and due to that it can

reach only the first %5= locations. :n order to ?eep already eisting #>bit architecture and

compatibility with other eisting models a little tric? has been used.

sing tric? in this case means that additional memory bloc? shares the same

addresses with eisting locations intended for the 27@s B#"h> 77hC. :n order to

differentiate between these two physically separated memory spaces, different ways of

addressing are used. A direct addressing is used for all locations in the 27@s, while the


42/85

POWER SUPPLY:

The input to the circuit is applied from the regulated power supply. The a.c. input

i.e., %&" from the mains supply is step down by the transformer to (% and is fed to a

rectifier. The output obtained from the rectifier is a pulsating d.c voltage. 2o in order to

get a pure d.c voltage, the output voltage from the rectifier is fed to a filter to remove any

a.c components present even after rectification. 6ow, this voltage is given to a voltage

regulator to obtain a pure constant dc voltage.

()=% AC

=H

DC

O$t#$t

@egulator

Filter

Bri,*eRecti-ierSte# ,o.ntran!-or"er


43/85

7igN ower supply

Tran!-or"er:

sually, J voltages are required to operate various electronic equipment and these

voltages are 5,


44/85

voltage and load is maintained constant. 3owever, if either of the two is varied, J..

voltage received at this point changes. Therefore a regulator is applied at the output stage.

%olta*e re*$lator:

As the name itself implies, it regulates the input applied to it. A voltage regulator

is an electrical regulator designed to automatically maintain a constant voltage level. :n

this project, power supply of 5 and (% are required. :n order to obtain these voltage

levels, !#"5 and !#(% voltage regulators are to be used. The first number !# represents

positive supply and the numbers "5, (% represent the required output voltage levels.

%OLTAGE REGULATOR >8=:

+eat$re!:

R 4utput urrent up to (A.

R 4utput oltages of 5, =, #,


45/85

An ideal capacitor is characteri0ed by a single constant value, capacitance, which is

measured in farads. This is the ratio of the electric charge on each conductor to the potential

difference between them. :n practice, the dielectric between the plates passes a small amount of

lea?age current. The conductors and leads introduce an equivalent series resistance and the

dielectric has an electric field strength limit resulting in a brea?down voltage.

The properties of capacitors in a circuit may determine the resonant frequency and

quality factor of a resonant circuit, power dissipation and operating frequency in a digital logic

circuit, energy capacity in a high>power system, and many other important aspects.

A capacitor Bformerly ?nown as condenserC is a device for storing electric charge. The

forms of practical capacitors vary widely, but all contain at least two conductors separated

by a non>conductor. apacitors used as parts of electrical systems, for eample, consist of

metal foils separated by a layer of insulating film.

T7eor3 o- o#eration:

1ain articleN


46/85

harge separation in a parallel>plate capacitor causes an internal electric field. A dielectric

BorangeC reduces the field and increases the capacitance.

A simple demonstration of a parallel>plate capacitor

A capacitor consists of two conductors separated by a non>conductive region The non>

conductive region is called the dielectric or sometimes the dielectric medium. :n simpler

terms, the dielectric is just an electrical insulator . )amples of dielectric mediums are

glass, air, paper, vacuum, and even a semiconductor depletion region chemically identicalto the conductors. A capacitor is assumed to be self>contained and isolated, with no net

electric charge and no influence from any eternal electric field. The conductors thus hold

equal and opposite charges on their facing surfaces, and the dielectric develops an electric

field. :n 2: units, a capacitance of one farad means that one coulomb of charge on each

conductor causes a voltage of one volt across the device. The capacitor is a reasonably

general model for electric fields within electric circuits. An ideal capacitor is wholly

characteri0ed by a constant capacitance , defined as the ratio of charge [K on each

conductor to the voltage between themN

http://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Dielectric_mediumhttp://en.wikipedia.org/wiki/Insulator_(electrical)http://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Depletion_regionhttp://en.wikipedia.org/wiki/Electric_chargehttp://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Faradhttp://en.wikipedia.org/wiki/Coulombhttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Dielectric_mediumhttp://en.wikipedia.org/wiki/Insulator_(electrical)http://en.wikipedia.org/wiki/Vacuumhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Depletion_regionhttp://en.wikipedia.org/wiki/Electric_chargehttp://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Faradhttp://en.wikipedia.org/wiki/Coulombhttp://en.wikipedia.org/wiki/Volt


47/85

2ometimes charge build>up affects the capacitor mechanically, causing its capacitance to

vary. :n this case, capacitance is defined in terms of incremental changesN

Ener*3 !tora*e:

C$rrent54olta*e relation

The current iBtC through any component in an electric circuit is defined as the rate of flow

of a charge qBtC passing through it, but actual charges, electrons, cannot pass through thedielectric layer of a capacitor, rather an electron accumulates on the negative plate for

each one that leaves the positive plate, resulting in an electron depletion and consequent

positive charge on one electrode that is equal and opposite to the accumulated negative

charge on the other. Thus the charge on the electrodes is equal to the integral of the

current as well as proportional to the voltage as discussed above. As with any

antiderivative, a constant of integration is added to represent the initial voltage v Bt"C. This

is the integral form of the capacitor equation,

.

Ta?ing the derivative of this, and multiplying by , yields the derivative form,

.

http://en.wikipedia.org/wiki/Integralhttp://en.wikipedia.org/wiki/Integralhttp://en.wikipedia.org/wiki/Antiderivativehttp://en.wikipedia.org/wiki/Constant_of_integrationhttp://en.wikipedia.org/wiki/Constant_of_integrationhttp://en.wikipedia.org/wiki/Integralhttp://en.wikipedia.org/wiki/Antiderivativehttp://en.wikipedia.org/wiki/Constant_of_integration


48/85

The dual of the capacitor is the inductor , which stores energy in the magnetic field rather

than the electric field. :ts current>voltage relation is obtained by echanging current and

voltage in the capacitor equations and replacing with the inductance /.

DC circ$it!

2ee alsoN @ circuit

A simple resistor>capacitor circuit demonstrates charging of a capacitor.

A series circuit containing only a resistor , a capacitor, a switch and a constant J source

of voltage " is ?nown as a charging circuit. :f the capacitor is initially uncharged while

the switch is open, and the switch is closed at t U ", it follows from +irchhoffs voltage

law that

Ta?ing the derivative and multiplying by , gives a first>order differential equation,

At t U ", the voltage across the capacitor is 0ero and the voltage across the resistor is ".

The initial current is then i B"C U" '@. With this assumption, the differential equation

yields

http://en.wikipedia.org/wiki/Duality_(electrical_circuits)http://en.wikipedia.org/wiki/Inductorhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/RC_circuithttp://en.wikipedia.org/wiki/Resistorhttp://en.wikipedia.org/wiki/Kirchhoff's_voltage_lawhttp://en.wikipedia.org/wiki/Kirchhoff's_voltage_lawhttp://en.wikipedia.org/wiki/First-order_differential_equationhttp://en.wikipedia.org/wiki/Duality_(electrical_circuits)http://en.wikipedia.org/wiki/Inductorhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/RC_circuithttp://en.wikipedia.org/wiki/Resistorhttp://en.wikipedia.org/wiki/Kirchhoff's_voltage_lawhttp://en.wikipedia.org/wiki/Kirchhoff's_voltage_lawhttp://en.wikipedia.org/wiki/First-order_differential_equation


49/85


50/85


51/85

apacitors are combined in series to achieve a higher wor?ing voltage, for eample for smoothing

a high voltage power supply. The voltage ratings, which are based on plate separation, add up. :n

such an application, several series connections may in turn be connected in parallel, forming a

matri. The goal is to maimi0e the energy storage utility of each capacitor without overloading

it.

2eries connection is also used to adapt electrolytic capacitors for A use.

E$i4alent circ$it

As frequency approaches infinity, the capacitive impedance Bor reactanceC approaches

0ero and the )2@ becomes significant. As the reactance becomes negligible, power

dissipation approaches @12 U @12] '@ )2@ .

2imilarly to )2@, the capacitors leads add equivalent series inductance or ESL to the

component. This is usually significant only at relatively high frequencies. As inductive

reactance is positive and increases with frequency, above a certain frequency capacitance

will be canceled by inductance. 3igh>frequency engineering involves accounting for the

inductance of all connections and components.

:f the conductors are separated by a material with a small conductivity rather than a

perfect dielectric, then a small lea?age current flows directly between them. The capacitor

therefore has a finite parallel resistance, and slowly discharges over time Btime may vary

greatly depending on the capacitor material and qualityC.

http://en.wikipedia.org/wiki/Electrolytic_capacitorhttp://en.wikipedia.org/wiki/Equivalent_series_inductancehttp://en.wikipedia.org/wiki/Electrolytic_capacitorhttp://en.wikipedia.org/wiki/Equivalent_series_inductance


52/85

A resistor is a two>terminal electronic component designed to oppose an electric current by

producing a voltage drop between its terminals in proportion to the current, that is, in accordance

with 4hms lawN

U :@

@esistors are used as part of electrical networ?s and electronic circuits. They are etremely

commonplace in most electronic equipment. ractical resistors can be made of various

compounds and films, as well as resistance wire Bwire made of a high>resistivity alloy, such as

nic?el'chromeC.

The primary characteristics of resistors are their resistance and the power they can

dissipate. 4ther characteristics include temperature coefficient, noise, and inductance. /ess well>

?nown is critical resistance, the value below which power dissipation limits the maimum

permitted current flow, and above which the limit is applied voltage. ritical resistance depends

upon the materials constituting the resistor as well as its physical dimensionsL its determined by

design.

@esistors can be integrated into hybrid and printed circuits, as well as integrated

circuits. 2i0e, and position of leads Bor terminalsC are relevant to equipment designersL resistors

must be physically large enough not to overheat when dissipating their power.

Unit!

The ohm BsymbolN ^C is the 2: unit of electrical resistance, named after Deorg 2imon

4hm. An ohm is equivalent to a volt per ampere. 2ince resistors are specified and

manufactured over a very large range of values, the derived units of milliohm B( m^ U

http://en.wikipedia.org/wiki/Ohm_(unit)http://en.wikipedia.org/wiki/%CE%A9http://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Georg_Simon_Ohmhttp://en.wikipedia.org/wiki/Georg_Simon_Ohmhttp://en.wikipedia.org/wiki/Georg_Simon_Ohmhttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Amperehttp://en.wikipedia.org/wiki/Amperehttp://en.wikipedia.org/wiki/Ohm_(unit)http://en.wikipedia.org/wiki/%CE%A9http://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Georg_Simon_Ohmhttp://en.wikipedia.org/wiki/Georg_Simon_Ohmhttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Ampere


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("_& ^C, ?ilo ohms B( ?^ U ("& ^C, and mega ohm B( 1^ U ("= ^C are also in common

usage.

The reciprocal of resistance @ is called conductance D U ('@ and is measured in 2iemens

B2: unitC, sometimes referred to as a mho. Thus a 2iemens is the reciprocal of an ohmN 2 U

^ _ (. Although the concept of conductance is often used in circuit analysis, practical

resistors are always specified in terms of their resistance BohmsC rather than conductance.

SYSTEM MODEL

The proposed system consists of a set of biomedical sensors attached with the

body of a patient. A wireless transmitter is used to send the data to a wireless receiver

connected to a local monitoring unit. :n this wor? we used si biomedical sensors to

monitor heart beat rate, temperature, changes in muscles power, and )D signals of a

patient. These sensors convert the physiological changes of the patient’s body into

biomedical signals. The conditioning circuit Bi.e., Arduino microcontrollerC reads the data

from the sensors and controls the transmission of data to a monitoring unit. The

monitoring unit displays the data that is used by the physicians for necessary medical

advices. The wireless receiver consists of Obee that receives data and sends it to the local

http://en.wikipedia.org/wiki/Conductancehttp://en.wikipedia.org/wiki/Conductancehttp://en.wikipedia.org/wiki/Siemens_(unit)http://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Mhohttp://en.wikipedia.org/wiki/Conductancehttp://en.wikipedia.org/wiki/Siemens_(unit)http://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Mho


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reports as well as alarming messages to the healthcare professionals. The system bloc?

diagram of the proposed system is shown in 7igure %.

$ased on the customer requirements the system hardware can be easily modified

to accommodate more sensors. The data transmission can also ta?e place via wired or

wireless channels. The proposed system can be connected to the :nternet for global

communication. :n addition, the proposed system is carefully implemented in hardware

and software system so that it can be adapted to fulfill the user’s requirements. 2ince

accuracy is one of the most important issues in biomedical signal processing, the

proposed system has been field tested etensively to ensure its accuracy. The system can

continuously monitor the health of a patient twenty four hours a day. The proposed

system is also able to inform the healthcare professionals about any unusual healthconditions of a patient. The doctors can also use the publishing system incorporated with

the system. When the measured data eceeds the allowable normal range, the system can

send an alarm message to the concerned healthcare professionals. The system can

facilitate healthcare professionals to perform immediate medical diagnosis and to

administer the medical treatment if needed. The system measures different physical

parameters of a patient by using four different sensors as shown in 7igure &. The

microcontroller receives the signals from the sensors and processes them before sending

them to a -ig$ee transmitter module. The transmitter module transmits the signal that is

received by the receiving antenna of the -ig$ee receiver.

BLOCK DIAGRAM:

TRANSMITTER

Microcontroller


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POWER SUPPLY:

Te"#erat$re!en!or

%iration

!en!or

&IGBEE

MA'

()(

%olta*ere*$lator

+ilterBri,*e

recti-ier

Ste#

,o.n

T/+


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RECEI%ER SECTION:


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The system bloc? diagram for the receiver is shown in 7igure ;. The receiver

antenna receives the data sent by the transmitting antenna and then the data are sent to a

Bi.e., 1onitoring nitC for display. The 1onitoring nit sends report using the internet

to the concerned healthcare professionals.

The temperature sensor used in our system is shown in 7igure 5BaC and the

associated program flowchart in shown in 7igure 5BbC. We used /1&5 sensor for our

project. The /1&5 is a high precision integrated temperature sensor. :t generates an

analog voltage depending on the temperature of the patient’s body. The sensor output

voltage is linearly proportional to the body temperature. The sensor circuitry is sealed and

is not subject to oidation. The /1&5 generates a higher output voltage than

thermocouples. The sensor can measure temperature and generate signal that is sent to amicrocontroller. The data are then transmitted by the -ig$ee to the . The sensors are

connected to the :'4 port of the : microcontroller Bi.e., ArduinoC. The output voltage is

converted into temperature by a simple conversion factor. As shown in 7igure = the

temperature sensor measures the temperature and converts it into electrical signal. The

electrical signal is then processed by a microcontroller and the /abiew software.

7inally, it is displayed in the monitoring unit. We set the normal body temperature

of a patient in the range of &=` > ;"`. :f the temperature reading is less than &=` or

more than ;"` degree the alarm will be 46 and it will send an alert message to the

concerned healthcare professional. The heart beat sensor used to measure the heartbeat of

the patient is shown in 7igure =BaC. This sensor monitors the flow of blood through a clip

that is attached with a fingertip. The sensor has a laser that emits light through the s?in

and measures the reflection of the laser due to the flow of the blood. The heart beat rate of

an individual may vary. At rest, an adult man has an average pulse rate of !% beats per

minute. Athletes normally have a lower pulse rate compared to that of a less active

people. 4n the other hand children have a higher pulse rate Bappro.


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+LOW CHART:

+i*: The measurement of heart beat rates


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placed at four different places of the patient’s body as shown in 7igure # and provides an

output as shown in 7igure of>sight,

depending on power output and environmental characteristics.8(9 -ig$ee devices can

transmit data over long distances by passing data through a mesh networ? of intermediate

devices to reach more distant ones. -ig$ee is typically used in low data rate applications

that require long battery life and secure networ?ing B-ig$ee networ?s are secured by (%#

bit symmetric encryption ?eys.C -ig$ee has a defined rate of %5" ?bit's, best suited for

intermittent data transmissions from a sensor or input device.

-ig$ee was conceived in (power, wireless mesh networ? standard targeted at the wide

https://en.wikipedia.org/wiki/IEEE_802.15.4https://en.wikipedia.org/wiki/Specification_(technical_standard)https://en.wikipedia.org/wiki/Specification_(technical_standard)https://en.wikipedia.org/wiki/Personal_area_networkhttps://en.wikipedia.org/wiki/Digital_radiohttps://en.wikipedia.org/wiki/Personal_area_network#Wireless_PANhttps://en.wikipedia.org/wiki/Personal_area_network#Wireless_PANhttps://en.wikipedia.org/wiki/Bluetoothhttps://en.wikipedia.org/wiki/Wi-Fihttps://en.wikipedia.org/wiki/Wi-Fihttps://en.wikipedia.org/wiki/Line-of-sight_propagationhttps://en.wikipedia.org/wiki/Line-of-sight_propagationhttps://en.wikipedia.org/wiki/ZigBee#cite_note-specs-1https://en.wikipedia.org/wiki/Mesh_networkinghttps://en.wikipedia.org/wiki/Symmetric-key_algorithmhttps://en.wikipedia.org/wiki/Waggle_dancehttps://en.wikipedia.org/wiki/Wireless_mesh_networkhttps://en.wikipedia.org/wiki/Wireless_mesh_networkhttps://en.wikipedia.org/wiki/IEEE_802.15.4https://en.wikipedia.org/wiki/Specification_(technical_standard)https://en.wikipedia.org/wiki/Personal_area_networkhttps://en.wikipedia.org/wiki/Digital_radiohttps://en.wikipedia.org/wiki/Personal_area_network#Wireless_PANhttps://en.wikipedia.org/wiki/Bluetoothhttps://en.wikipedia.org/wiki/Wi-Fihttps://en.wikipedia.org/wiki/Wi-Fihttps://en.wikipedia.org/wiki/Line-of-sight_propagationhttps://en.wikipedia.org/wiki/ZigBee#cite_note-specs-1https://en.wikipedia.org/wiki/Mesh_networkinghttps://en.wikipedia.org/wiki/Symmetric-key_algorithmhttps://en.wikipedia.org/wiki/Waggle_dancehttps://en.wikipedia.org/wiki/Wireless_mesh_network


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typically integrated with radios and with microcontrollers that have between =">%5= +$

flashes memory. -ig$ee operates in the industrial, scientific and medical B:21C radio

bandsN %.; D30 in most jurisdictions worldwideL !#; 130 in hina, #=# 130 in )urope

and style self>organi0ing ad>hoc digital radio networ?s were conceived in the

(


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Licen!e

7or non>commercial purposes, the -ig$ee specification is available free to the general

public.8(%9 An entry level membership in the -ig$ee Alliance, called Adopter, provides

access to the as>yet unpublished specifications and permission to create products for

mar?et using the specifications.

The requirements for membership in the -ig$ee Alliance cause problems for 7ree

2oftware developers because the annual fee conflicts with the D6 Deneral ublic

/icence.8(&9The requirement for the developer to join the -ig$ee Alliance similarly

conflicts with most other free software licenses.8(;9

The -ig$ee Alliance board has been as?ed to ma?e their license compatible with D/,

but refused. The refusal came, even though $luetooth had already changed their license to

ma?e it consistent with D/.

A##lication #ro-ile!

The current list of application profiles either published, or in development areN

Released specifications

• -ig$ee 3ome Automation (.%

• 2mart )nergies (.(b

• Telecommunication 2ervices (."

• 3ealth are (."

• @7;) @emote ontrol (."

• @7;) :nput Jevice (."

• @emote ontrol %."

• /ight /in? (."

• : (."

• $uilding Automation (."

• Dateway (."

• Dreen ower (." B4ptional battery>less remote control feature of -ig$ee %"(%C

https://en.wikipedia.org/wiki/ZigBee#cite_note-12https://en.wikipedia.org/wiki/GNU_General_Public_Licencehttps://en.wikipedia.org/wiki/GNU_General_Public_Licencehttps://en.wikipedia.org/wiki/ZigBee#cite_note-13https://en.wikipedia.org/wiki/Free_softwarehttps://en.wikipedia.org/wiki/ZigBee#cite_note-14https://en.wikipedia.org/wiki/ZigBee#cite_note-14https://en.wikipedia.org/wiki/Software_licensehttps://en.wikipedia.org/wiki/License_compatibilityhttps://en.wikipedia.org/wiki/License_compatibilityhttps://en.wikipedia.org/wiki/Bluetoothhttps://en.wikipedia.org/wiki/Bluetoothhttps://en.wikipedia.org/wiki/ZigBee#cite_note-12https://en.wikipedia.org/wiki/GNU_General_Public_Licencehttps://en.wikipedia.org/wiki/GNU_General_Public_Licencehttps://en.wikipedia.org/wiki/ZigBee#cite_note-13https://en.wikipedia.org/wiki/Free_softwarehttps://en.wikipedia.org/wiki/ZigBee#cite_note-14https://en.wikipedia.org/wiki/Software_licensehttps://en.wikipedia.org/wiki/License_compatibilityhttps://en.wikipedia.org/wiki/Bluetooth


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Specifications under development

• -ig$ee 2mart )nergy %."

• 2mart )nergy (.%'(.&

• /ight /in? (.(

• 3ome Automation (.&

The &i*Bee S"art Ener*3 %(= specifications define an :nternet protocol to monitor,

control, inform and automate the delivery and use of energy and water. :t is an

enhancement of the -ig$ee 2mart )nergy version ( specifications. 8(59 :t adds services

for plug>in electric vehicle charging, installation, configuration and firmware download,

prepay services, user information and messaging, load control, demand response and

common information and application profile interfaces for wired and wireless networ?s. :t

is being developed by partners includingN

• 3omeDrid 7orum responsible for mar?eting and certifying :T>

T D.hn technology and products

• 3omelug owerline Alliance

•:nternational 2ociety of Automotive )ngineers 2A) :nternational

• :24 Alliance

• 2un2pec Alliance

• Wi>7i Alliance.

:n %""top boes. :t promised many advantages over eisting remote control

solutions, including richer communication and increased reliability, enhanced features

and fleibility, interoperability, and no line>of>sight barrier.8(=9 The -ig$ee @7;)

specification lifts off some networ?ing weight and does not support all the mesh features,

which is traded for smaller memory configurations for lower cost devices, such as remote

control of consumer electronics.

With the introduction of the second -ig$ee @7;) application profile in %"(% and

increased momentum in 124 mar?et, the -ig$ee @7;) team provides an overview on

current status of the standard, applications, and future of the technology.

https://en.wikipedia.org/wiki/Internet_protocolhttps://en.wikipedia.org/wiki/ZigBee#cite_note-15https://en.wikipedia.org/wiki/Plug-in_electric_vehiclehttps://en.wikipedia.org/wiki/Demand_responsehttps://en.wikipedia.org/wiki/G.hnhttps://en.wikipedia.org/wiki/G.hnhttps://en.wikipedia.org/wiki/G.hnhttps://en.wikipedia.org/wiki/HomePlughttps://en.wikipedia.org/wiki/SAE_Internationalhttps://en.wikipedia.org/wiki/Wi-Fi_Alliancehttps://en.wikipedia.org/wiki/ZigBee#cite_note-16https://en.wikipedia.org/wiki/Internet_protocolhttps://en.wikipedia.org/wiki/ZigBee#cite_note-15https://en.wikipedia.org/wiki/Plug-in_electric_vehiclehttps://en.wikipedia.org/wiki/Demand_responsehttps://en.wikipedia.org/wiki/G.hnhttps://en.wikipedia.org/wiki/HomePlughttps://en.wikipedia.org/wiki/SAE_Internationalhttps://en.wikipedia.org/wiki/Wi-Fi_Alliancehttps://en.wikipedia.org/wiki/ZigBee#cite_note-16

Documents

ICU Patient Monitoring System With Automatic SMS System Using GSM ZIGBEE Wireless Technology