Post on 11-May-2017
A Seminar Report on Multi-Focus Image Fusion
TEMPERATURE SENSOR USING
MICROCONTROLLER USING 8051
B Tech (Telecommunication), Project Stage - I
By
Prateek Dua(723)
Sudhanshu Sharma(742)
Vimanyu Kachroo(747)
Under the Guidance of
Prof. Rahul Koshti
Department of Electronics and Telecommunication Engineering
S.V.K.M’s NMIMS, Mukesh Patel School of Technology
Management and Engineering.
i
Acknowledgement
Apart from, the success of my seminar depends largely on the encouragement and
guidelines of many others. I take this opportunity to express my gratitude to the
people who have been instrumental in the successful completion of this seminar.
I would like to show my greatest appreciation to Prof. Rahul Koshti, my project
guide. I can’t say thank them enough for their tremendous support and help.
Without their encouragement and guidance this seminar would not have
materialized.
I am grateful for the guidance, support and help received from other members who
contributed and contributing to this seminar which is vital for the success of this
seminar.
Name of Student: Prateek Dua(723)
Sudhanshu Sharma(742)
Vimanyu Kachroo(747)
Btech(EXTC)
Abstract
An analog temperature sensor is pretty easy to explain, it’s a chip that tells you
what the ambient temperature is!
These sensors use a solid-state technique to determine the temperature. That is to
say, they don’t use mercury (like old thermometers), bimetallic strips (like in some
home thermometers or stoves), nor do they use thermostats (temperature sensitive
resistors). Instead, they use the fact as temperature increases, the voltage across a
diode increases at a known rate.
By precisely amplifying the voltage change, it is easy to generate an analog signal
that is directly proportional to temperature. There have been some improvements
on the technique but, essentially that is how temperature is measured.
Because these sensors have no moving parts, they are precise, never wear out, don't
need calibration, work under many environmental conditions, and are consistent
between sensors and readings. Moreover they are very inexpensive and quiet and
quite easy to use
Table of Contents
No. Title Page No.
Acknowledgement
Abstract
1. Introduction 1
2. Literature Review 3
3. Hardware used 4
3.1 Block diagram
4. Hardware information 6
4.1 Introduction to Micro controller
4.2 A/D Converter
4.3 LM35 Temperature Sensor
4.4 Resistors
4.5Capacitors
5. Applications 14
6. Future development 15
7. Reference 16
List of Figures
Figure 2.1 : Flow diagram 3
Figure 3.1 : Block diagram 5
Figure 4.1 : Pin diagram of AT89C51 6
Figure 4.3 : LM 35 diagram 11
Figure 4.4 : color coded resistor 12
Figure 4.5 : Capacitor symbol 12
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1. Introduction
The aim of this project is to design an ambient temperature measurement circuit.
The motivation for doing this project is the fact that temperature measurement has
become an integral part of any control system operating in a temperature sensitive
environment and the various learning outcomes associated during the
implementation of the project.
In this project the ambient temperature will be displayed on a LCD. An 89s52
Microcontroller will be used for handling all the required computations and
control.
In following we have briefly discussed details of a Microcontroller and the project
in general. A temperature sensor LM 35 is used for sensing the ambient
temperature. The system will get the temperature from the IC and it will display
the temperature over the seven segment display and this temperature was compared
with the value stored by the user. The main work of the project is to sense the
temperature and display it and then control it by using relays. Now to display a
temperature we have to just convert the temperature which is analog into a digital
quantity by using an analog to digital convertor that is referred as ADC or A/D
convertor.
To control a temperature sensitive device we refer a range of temperature which
with compared by the current temperature that is sensed by the temperature sensor.
The temperature based applications are based on mostly on three types these are:-
1 .Under temperature application
2. Over temperature application
3. Power tripping application
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2. Literature Review
There are many aspects that should be considered when measuring temperature;
the needs of a home refrigerator are different to those of a commercial furnace, or
those for monitoring liquids flowing through pipes in a beverage-processing plant.
The previous application examples present very different challenges to those
encountered when measuring the temperature within the housing of a cell phone or
laptop computer. While each of these applications need to measure temperature,
they all have very different requirements. Some considerations are how hot, where
is the temperature being measured and how precise does the measurement need to
be.
Now for an example if equipment is working continuously then it becomes heated.
Due to heating the insulation of that particular device is being molten. And now it
become slow or we can say that it become less efficient.
To prevent this condition we continuously monitor the device temperature. The
work of relay to control temperature is depends on the surrounding conditions, like
if the device is over heated then the reference range of temperature. At this time we
have to avoid the overheating & provide cooling to the device.
But in those countries where the snow fall occurs then the device is become under
heating then to avoid this condition we have to provide heating to the device.
And if the device exceeds the temperature range which is previously define by us,
then the device is being turned OFF or we can say that the device is being tripped.
The above discussed three cases are operated by three different relays. One relay
provide heating by heater which is connected to the relay; this relay is activated
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when the “UNDER TEMPERATURE” condition occur. Once heater is on the
device starts heating & works properly as required.
The second relay provides cooling to the device by a fan or blower which is
connected with relay, this relay activated when over temperature condition occurs.
Due to this the device becomes cooled.
If the temperature range get out of the range of reference range then required to on
the fan or blower. But if in case the fan is not in working condition and the device
temperature is exceeds the relay tripped the device to prevent the damage. It is
used for safety purpose. In this whole system is using the oscillation frequency
11.0592MHz. all the relays are connected with the transistors at active high mode
so as buzzer is also connected in the active high mode with the transistor.
Figure 2.1 flow diagram
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3. Hardware Used
Microcontroller AT89S52(8052 derivative).
IC DS 1820 (Temperature Sensor).
LM 7805 (Regulator IC for 5 volts constant D.C supply
LCD For display at remote station.
Crystal Oscillator to produce 11.0592 MHz Frequency for microcontroller
clock.
General Purpose PCB Software Used.
Keil u-Vision 3.0:-
Keil Software is used provide you with software development tools for 8051
based microcontrollers. With the Keil tools, you can generate embedded
applications for virtually every 8051 derivative.
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3.1 BLOCK DIAGRAM
Figure 3.1 block diagram
4. HARDWARE INFORMATION
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4.1 Introduction to Micro controller
When we have to learn about a new computer we have to familiarize about the
machine capability we are using, and we can do it by studying the internal
hardware design (devices architecture), and also to know about the size, number
and the size of the registers. A microcontroller is a single chip that contains the
processor (the CPU), non-volatile memory for the program (ROM or flash),
volatile memory for input and output (RAM), a clock and an I/O control unit. Also
called a "computer on a chip," billions of microcontroller units (MCUs) are
embedded each year in a myriad of products from toys to appliances to
automobiles. For example, a single vehicle can use 70 or more microcontrollers.
Figure 4.1:
Pin diagram of
AT89C51
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89s52: The AT89S52 is a low-power, high-performance CMOS 8-bit
microcontroller with 8K bytes of in-system programmable Flash memory. The
device is manufactured using Atmelâ„¢s high-density nonvolatile memory
technology and is compatible with the industry-standard 80C51 instruction set and
pinout. The on-chip Flash allows the program memory to be reprogrammed in-
system or by a conventional nonvolatile memory programmer. By combining a
versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the
Atmel's AT89S52 is a powerful microcontroller which provides a highly-flexible
and cost-effective solution to many embedded control applications.
In addition, the AT89S52 is designed with static logic for operation down to zero
frequency and supports two software selectable power saving modes. The Idle
Mode stops the CPU while allowing the RAM, timer/counters, serial port, and
interrupt system to continue functioning. The Power-down mode saves the RAM
con-tents but freezes the oscillator, disabling all other chip functions until the next
interrupt The hardware is driven by a set of program instructions, or software.
Once familiar with hardware and software, the user can then apply the
microcontroller to the problems easily. The following are some of the capabilities
of 8051 microcontroller.
Internal ROM and RAM
I/O ports with programmable pins
Timers and counters
Serial data communication
The 8051 architecture consists of these specific features:
16 bit PC &data pointer (DPTR)
8 bit program status word (PSW)
8
8 bit stack pointer (SP)
Internal ROM 4k
Internal RAM of 128 bytes.
4 register banks, each containing 8 registers
0 bits of general purpose data memory
32 input/output pins arranged as four 8 bit ports0-P3
Two 16 bit timer/counters: T0-T1
Two external and three internal interrupt sources
Oscillator and clock circuits.
4.2 A/D Converter.
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ADC0804:
ADC0804 is a very commonly used 8-bit analog to digital convertor. It is a single
channel IC. The digital outputs vary from 0 to a maximum of 255. ADC0804 needs
a clock to operate. The time taken to convert the analog value to digital value is
dependent on this clock source. An external clock can be given at the Clock IN pin
Pin Description:
Pin No
Function Name
10
1 Activates ADC; Active low Chip select
2 Input pins Read
3 Input pin; Low to high
pulse is given to start the
conversion
Write
4 Clock Input pin; to give
external clock.
Clock IN
5 Output pin; Goes low when
conversion is complete
Interrupt
6,7 Analog non-inverting input
& Analog inverting Input.
Vin(+) & Vin(-)
8 Ground(0V) Analog Ground
9 Input pin; sets the reference
voltage for analog input
Vref/2
10 Ground(0V) Digital Ground
11to18 8 bit digital output pins D7 to D0
19 Used with Clock IN pin
when internal clock source
is used
Clock R
20 Supply voltage; 5V Vcc
4.3 LM35 Temperature Sensor
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LM35 is a precision IC temperature sensor with its output proportional to the
temperature (in oC). The sensor circuitry is sealed and therefore it is not subjected
to oxidation and other processes. With LM35, temperature can be measured more
accurately than with a thermistor. It also possess low self heating and does not
cause more than 0.1 oC temperature rise in still air. The LM35 series are precision
integrated-circuit LM35 temperature sensors, whose output voltage is linearly
proportional to the Celsius (Centigrade) temperature. The LM35 sensor does not
require any external calibration or trimming to provide typical accuracies of ±¼°C
at room temperature and ±¾°C over a full -55 to +150°C temperature range.
It can be used with single power supplies, or with plus and minus supplies. As it
draws only 60 μA from its supply, it has very low self-heating, less than 0.1°C in
still air. The LM35 is rated to operate over a -55° to +150°C temperature range,
while the LM35C sensor is rated for a -40° to +110°C range (-10° with improved
accuracy).
Figure 4.3 LM35diagram
4.4 Resistors
Resistor is a passive
component used to control current in a circuit. Its resistance is given by the ratio of
voltage applied across its terminals to the current passing through it. Resistors can
be either fixed or variable. Negative temperature coefficient (NTC), positive
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temperature coefficient (PTC) and light dependent resistor (LDR) are some such
resistors. These special resistors are commonly used as sensors. Read and learn
about internal structure and working of a resistor.
Figure 4.4: color coded Resistors
4.5 Capacitors
A capacitor is a passive two terminal component which stores electric charge. This
component consists of two conductors which are separated by a dielectric medium.
The potential difference when applied across the conductors polarizes the dipole
ions to store the charge in the dielectric medium. The circuit symbol of a capacitor
is shown below:
Figure 4.5 capacitor symbol
As you turn on the power supply, the current begins to flow through the capacitor
inducing the positive and negative potentials across its plates. The capacitor
continues to charge until the capacitor voltage equalizes up to the supply voltage
which is called as the charging phase of the capacitor. Once the capacitor is fully
charged at the end of this phase, it gets open circuited for DC. It begins to
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discharge when the power of the capacitor is switched off. There are different
types of capacitors. The symbol of capacitors from each group is shown below.
5. Applications
This project can be used in Home.
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This project can be used in Industry.
This will help in saving the electricity / energy.
FUTURE DEVELOPMENT
We can monitor parameters like humidity, light and at the same time control
them.
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We can send this data to remote location using mobile or internet.
We can draw graphs of variations in these parameters using computer.
REFERENCE:-
8051 and embedded system by Mazidi and Mazidi
All datasheets from http://www.datasheetcatalog.com
About AT89s8252 from http://www.atmel.com ,
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http://www.triindia.co.in
About DS1820 from http://www.dallas.com.