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DESIGN OF DATA LOGGER USING LabVIEW
A PROJECT REPORT
Submitted bySAAJAN DEHURY [Reg No: 11707067]SAURABH GUPTA [Reg No: 11707073]
SIDDHARTH PANICKER [Reg No: 11707077]
Under the guidance of
Mrs. B.HEMALATHA
(Assistant Professor, Department of Instrumentation and Control Engineering)
in partial fulfilment for the award of the degree
of
BACHELOR OF TECHNOLOGY
in
ELECTRONICS AND INSTRUMENTATION ENGINEERING
of
FACULTY OF ENGINEERING & TECHNOLOGY
S.R.M. Nagar, Kattankulathur, Kancheepuram District
MAY 2011
1
SRM UNIVERSITY(Under Section 3 of UGC Act, 1956)
BONAFIDE CERTIFICATE
Certified that this project report titled “DESIGN OF DATA LOGGER USING
LabVIEW” is the bonafide work of SAAJAN DEHURY Reg. No. 11707067, SAURABH
GUPTA Reg. No. 11707073 and SIDDHARTH PANICKER Reg. No. 11707077, who
carried out the project work under my supervision. Certified further, that to the best of my
knowledge the work reported herein does not form any other project report or dissertation on
the basis of which a degree or award was conferred on an earlier occasion on this or any other
candidate.
SIGNATURE SIGNATURE
Mrs.B.HEMALATHA Dr.A.VIMALA JULIET
HEAD OF THE DEPARTMENT
Assistant Professor ICE ICE
Signature of the Internal Examiner Signature of the External Examiner
2
ABSTRACT
Recent advances in electronics miniaturization have allowed the commercial
development of sensor/data logger combinations that are sufficiently
inexpensive and appear to be sufficiently accurate to deploy in measurement
arrays to resolve local atmospheric structure over periods of weeks to months.
A data logger is an electronic device that records data over time or in
relation to location either with a built in instrument or sensor or via external
instruments and sensors. Increasingly, but not entirely, they are based on a
digital processor (or computer). They generally are small, battery powered,
portable, and equipped with a microprocessor, internal memory for data storage,
and sensors. Some data loggers interface with a personal computer and utilize
software to activate the data logger to view and analyze the collected data, while
others have a local interface device (keypad, LCD) and can be used as a stand-
alone device.
We are recording various parameters- Temperature, Pressure and Humidity-
and analyzing this data using LabVIEW. For various purposes like agriculture,
meteorological forecast, weather forecast, terrain inspection, pollution values
etc, we need regular information regarding meteorological parameters and their
values.
After recording this information, we are transferring this data using
communication protocols like SMTP. All this is being done using LabVIEW,
which is faster and more efficient software.
3
ACKNOWLEDGEMENT
Apart from the efforts of me, the success of this project 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 project.
I would like to show my greatest appreciation to Assistant Professor Mrs.B.Hemalatha. I
can’t say thank you enough for her tremendous support and help. I feel motivated and
encouraged every time I attend her meeting. Without her encouragement and guidance this
project would not have materialized.
The guidance and support received from all the team members including Saurabh Gupta
and Siddharth Panicker who contributed and are contributing to this project, was vital for the
success of the project. I am grateful for their constant support and help.
4
TABLE OF CONTENTS
CHAPTER NO. PAGE NO.
ABSTRACT 2
LIST OF TABLE 6
LIST OF FIGURES 7
1. INTRODUCTION 8
2. SURVEY 12
3. SENSORS AND COMPONENTS 18
3.1 HUMI DITY SENSORS 19
3.2 TEMPERATURE SENSORS 22
3.3 PRESSURE SENSORS 26
3.4 AMPLIFIER CIRCUIT 31
3.5 VOLTAGE REGULATOR/IC7805 33
3.6 VOLTAGE REGULATOR/IC7812 39
3.7 VOLTAGE REGULATOR/IC 7815 40
4. BLOCK DIAGRAMS 41
5. LabVIEW 43
6. COMMUNICATION 57
7. FUTURE ENHANCEMENTS 59
8. CONCLUSION 60
9. REFERENCES
5
LIST OF TABLES
Table Page
1. Temperature Survey 12
2. Specifications of humidity sensor 19
3. Standard characteristics of humidity sensor 20
4. Absolute Maximum ratings of Pressure Sensor 29
5. Maximum ratings of amplification IC 7805 36
6
LIST OF FIGURES Page
Chapter 1
1. Hourly average of temperature 13
2. Daily variation of temperature 14
3. Daily variation of temperature 15
4. Daily variation of temperature 16
Chapter 21. Humidity sensor SY-HS-220 18
2. Characteristic curve of Humidity Sensor 21
3. Pin configuration of Temperature Sensor 23
4. Connection of Temperature Sensor 24
5. Connection of Pressure Sensor 27
6. Internal circuit diagram of LM324 31
7. Pin layout of IC7805 33
8. Internal Block diagram of IC7805 35
9. Top view of TO-220 packaging 38
Chapter 31. Amplification circuit 40
2. Connection of LM35DZ with the amplification IC LM324 41
3. Connection of pressure sensor ICS 1220 with amplification IC LM324 42
Chapter 41. NI USB-6008 45
2. Creation of sender’s e-mail id 46
3. Activation of SMTP 47
4. Storing data in the file 48
5. Acquiring the signals & filtering 49
6. Front panel depicting controls & indicators 50
7. Selecting the measurement type 51
7
8. Selecting the measurement type 52
CHAPTER 1
INTRODUCTION
Data loggers vary between general purpose types for a range of measurement
applications to very specific devices for measuring in one environment or application type
only. It is common for general purpose types to be programmable; however, many remain as
static machines with only a limited number or no changeable parameters. Electronic data
loggers have replaced chart recorders in many applications.
One of the primary benefits of using data loggers is the ability to automatically collect
data on a 24-hour basis. Upon activation, data loggers are typically deployed and left
unattended to measure and record information for the duration of the monitoring period. This
allows for a comprehensive, accurate picture of the environmental conditions being
monitored, such as air temperature and relative humidity.
With the development of computer technology, modern measurement technology, and
electronic instrument technology, virtual instrument becomes mainstream direction of current
instrument development because of its characteristics of high efficiency, man-machine
interactive interface good, convenience of reconstructed system, self-defining function, and
so on.
Designing this system used this method can improve the detection of wind speed,
temperature, humidity. At the same time, a user can operate this system only by using
keyboard or mouse. In a word, this system constructed by this way becomes convenient.
8
LabVIEW contains a comprehensive set of tools for acquiring, analyzing, displaying, and
storing data, as well as tools to help us troubleshoot code we write.
In LabVIEW, we can build a user interface, or front panel, with controls and indicators.
Controls are knobs, push buttons, dials, and other input mechanisms. Indicators are graphs,
LEDs, and other output displays. After we build the user interface, we add code using VIs
and structures to control the front panel objects. The block diagram contains this code. We
can also use LabVIEW to communicate data to other devices.
Also, data acquisition is easy in LabVIEW. Sensors are used for measuring temperature
and humidity. By constructing an amplification circuit, the properly calibrated values can be
obtained.
By using temperature sensor LM35DZ and humidity sensor HS-SY220, we can get the
temperature and relative humidity in the ambient atmosphere.
By using pressure sensor ICS1220, we can get the pressure in the ambient atmosphere.
9
Advantage of Data Logger over other collection instruments
Three types of instruments are commonly used for collecting and storing data. They are:
Real-Time Data Acquisition Systems
Chart Recorders
Data Loggers
Data loggers are normally more economical than chart recorders. They offer more
flexibility and are available with a greater variety of input types. Most data loggers collect
data which may be directly transferred to a computer. Although this option is available
with some recorders, it normally adds significant expense to the recorder price.
Data acquisition systems offer a great deal of flexibility and are certainly attractive when
high sample rates are required, however, since they require connection or installation into a
computer, the computer must also be present and active when collecting the data. Data
loggers can collect data independently of a computer. Data is normally collected in non-
volatile memory for later download to a computer. The computer does not need to be present
during the data collection process. This makes them ideally suited for applications requiring
portability.
The Maximum Sample Rate for a Data Logger
10
The sample rate depends on the specific model. Although most data loggers have a
maximum data rate of 1 or 2 samples per second, some data loggers can sample in excess of
100 samples per second.
Power Source for Data Loggers
Most data loggers are battery powered some also offer an option for external power.
Parameters involved in the battery life of a Data Logger
The battery life of a data logger depends on a number of parameters including the specific
model and sample rate. In general the faster the sample rate the shorter the battery life.
Recording Duration
The recording duration is dependent on the memory capacity of the data logger and the
desired sample rate. To determine the duration divide the memory capacity (number of
samples the device can record) by the sample rate. As an example assume that a given data
logger can store 10,000 samples. If it is desired to record 2 samples every minute, the data
logger can run for 10,000/2 or 5,000 minutes (about 3.5 days). If the sample rate was cut in
half (1 sample per minute), the recording period would double to 7 days.
CHAPTER 2
11
SURVEY
Presented in the following few pages is the results of a survey that has been done. This
survey includes values and trends of various metrological parameters.
Table 1: Temperature survey
The above given data is obtained from the campus of SRM University, and was taken in
the year 2009-2010. The temperature sets given are the monthly maximum and minimum
temperature values obtained. Based on this empirical data, many experiments of high
importance can be carried out with a high efficacy.
12
Fig. 1: Hourly average for Temperature
The data is then taken and plotted on a graph. A trend is obtained, which is depicted above.
The following results can be obtained from the aforementioned data:
• Temperatures vary between 24 and 35 deg with lower averages in the beginning of
2010.
13
Fig. 2: Daily variation of temerature
Daily variation of temperature from July-2009 to August-2009
14
Fig.3: Daily variation of temperature
Daily variation of temperature from September-2009 to December-2009
15
Fig.4: Daily variation of temperature
Daily variation of temperature from January 2010 to February 2010
16
CHAPTER 3
SENSORS AND COMPONENTS
In this chapter, all the sensors and other components used in the project are discussed.
The sensors and components form the most important part of our project, the electronics.
A humidity sensor is an instrument used for measuring the moisture content in the
environmental air, or humidity. Humidity is difficult to measure accurately. Most
measurement devices usually rely on measurements of some other quantity such as
temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is
absorbed. From calculations based on physical principles, or especially by calibration with a
reference standard, these measured quantities can lead to a measurement of humidity. The
humidity sensor is a four-terminal device.
A temperature sensor is a device that measures temperature or temperature gradient using
a variety of different principles. The temperature sensor accurately measures the temperature,
and gives an electrical voltage as output when the temperature is given as an input. The
temperature sensor device is a three-terminal device.
A pressure sensor is a device that takes the atmospheric pressure as an input, and gives a
corresponding electrical signal as an output. The pressure sensor used here is an eight-
terminal device.
The output signals of all the sensors have to be amplified. For that purpose, we design an
amplifier circuit.
The power source should give a regulated voltage as source. For that purpose, a voltage
regulator is being used.
17
1. HUMIDITY SENSOR SY-HS-220
Fig. 1: Humidity sensor SY-HS-220
The humidity sensor SY-HS-220 is a four-terminal device, and it takes the humidity from the atmosphere as the input, and gives electrical signal as the output.
18
Table 2:Specifications of Humidity Sensor
19
Table 3:Standard characteristics of Humidity Sensor
20
Fig. 2: Characteristics Curve for Humidity Sensor
2. TEMPERATURE SENSOR LM35DZ
The LM35 series are precision integrated-circuit temperature sensors, whose output
voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has
an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required
to subtract a large constant voltage from its output to obtain convenient Centigrade scaling.
The LM35 does not require any external calibration or trimming to provide typical
accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature
range. Low cost is assured by trimming and calibration at the wafer level.
The LM35’s low output impedance, linear output, and precise inherent calibration make
interfacing to readout or control circuitry especially easy. 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.
21
The LM35 is rated to operate over a −55° to +150°C temperature range, while the
LM35C is rated for a −40° to +110°C range (−10° with improved accuracy). The LM35
series is available packaged in hermetic TO-46 transistor packages, while the LM35C,
LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The
LM35D is also available in an 8-lead surface mount small outline package and a plastic TO-
220 package.
FEATURES
1. Calibrated directly in ° Celsius (Centigrade)
2. Linear + 10.0 mV/°C scale factor
3. 0.5°C accuracy guaranteeable (at +25°C)
4. Rated for full −55° to +150°C range
5. Suitable for remote applications
6. Low cost due to wafer-level trimming
7. Operates from 4 to 30 volts
8. Less than 60 μA current drain
9. Low self-heating, 0.08°C in still air
10. Nonlinearity only ±1⁄4°C typical
11. Low impedance output, 0.1 W for 1 mA load
The above given features are of the temperature sensor, LM35DZ. The linearity of the
LM35DZ, and its high accuracy make it a very viable choice for our project.
It is a low cost high efficiency model. It also has a very wide range of -55° to +150°C,
which comprises all our possible outputs.
22
CONNECTION DIAGRAMS
Fig. 3:Pin configuration of Temperature Sensor
The above shown sensor is a three-terminal device. The first terminal is the supply
voltage terminal, where the supply is provided. The third terminal is the ground terminal,
which is always grounded. The second terminal is the output voltage terminal. To see the
output, this terminal has to be checked. The output voltage is taken out from the second
terminal. To check the output voltage, a voltmeter should be connected in between the second
and the third terminal.
23
APPLICATION
Fig. 4:Connection of Temperature Sensor LM35DZ
The above shown diagram is of LM35DZ, the temperature sensor. It is a three-terminal
device, with the second terminal, i.e. the output terminal, connected to a resistance R1. The
value of R1 is computed based on the above given formula.
Absolute Maximum Ratings
1. Supply Voltage +35V to −0.2V
2. Output Voltage +6V to −1.0V
3. Output Current 10 mA
24
3. Pressure Sensor / ICS1220
The ICS1220 series of solid state pressure sensors are designed to provide a cost effective
solution for applications that require calibrated performance over a wide temperature range.
Packaged in a dual-in-line configuration, the ICS1220 series is intended for printed circuit
board mounting. Optional pressure port and lead configurations give superior flexibility in
low profile applications where pressure connection orientation is critical. The ICS1220 series
is based on NovaSensor’s advanced SenStable piezoresistive sensing technology.
Silicon micromachining techniques are used to ion implant piezoresistive strain gages
into a Wheatstone bridge configuration. The ICS1220 offers the added advantage of superior
temperature performance over the temperature compensated range of 0°C to +60°C. A
current set resistor is included to normalize the full scale output for field interchangeability.
Additionally, the ICS1220 series is available in pressure ranges from 0 to 5 through 0 to 100
psi.
Integral temperature compensation is provided over a range of 0-50°C using laser-
trimmed resistors. An additional laser-trimmed resistor is included to normalize pressure
sensitivity variations by setting the current drive to the sensor bridge, resulting in an
interchangeability of ±1% prior to amplification.
Gage, absolute, and differential pressure ranges from 0-2 PSI to 0-100 PSI are available.
Multiple lead and tube configurations are also available for customizing the package for
specific applications.
A few important features of pressure sensor ICS1220 are given below. These features are very conducive to our project, and these features are the reasons why we have selected ICS1220 for our project.
25
Features
• 50 mV Full-scale Output
• ±0.1% accuracy
• Interchangeable
• Temperature Compensated 0°C to 60°C
• PCB mountable package
• DIP package
• Solid state reliability
• Individual device traceability
The high accuracy of ICS1220, and the interchangeability makes it a very good option for
our project.
26
Pressure Ranges
• Gauge and differential
5, 15, 30, 50 and 100psi
• Absolute: 15, 30, 50 and 100psi
(5psi: call Nova Sensor)
Fig.5:Connection diagram of Pressure Sensor
The above given circuit is the pressure sensor circuit. The dotted boundary is the pressure
sensor, and as shown it has eight terminals. A1 is an operational amplifier, and the output is
taken from the first and the third terminals of the pressure sensor.
27
1. For 2 psi output on a 5 psi sensor span is 20.0 mV ± 1%, amplified span is 1.232V and
zero temperature error is ±1.25%.
2. Compensation resistors are an integral part of the sensor package; no additional external
resistors are required. Pins 7 and 8 must be kept open.
3. Best Fit Straight Line.
4. Temperature range: 0-50°C in reference to 25°C.
5. For a zero-to-full scale pressure step change.
6. 10 Hz to 1 kHz.
7. Prevents increase of TC-Span due to output loading.
8. 3X or 200 psi maximum, whichever is less. 20 psi for 2 psi and 5 psi versions.
9. Wetted materials are glass, ceramic, silicon, RTV, nickel, gold, and aluminum.
10. Soldering of lead pins: 250°C for 5 seconds maximum.
11. Tube length: L=470 ± 5 mil, S=300 ± 3 mil, N=no tube.
12. Lead pins can either be in the same or the opposite direction as the pressure tube. See
Dimensions drawing for lead configurations.
Applications
• Industrial automation
• Air flow monitors
• Agriculture
• Process control
• Medical equipment
• Underground cable leak detection
28
Absolute Maximum Ratings
Table 4:Absolute Maximum Ratings of Pressure Sensor
29
4. AMPLIFICATION CIRCUIT/ LM324
General Description
The LM124 series consists of four independent, high gain, internally frequency
compensated operational amplifiers which were designed specifically to operate from a single
power supply over a wide range of voltages. Operation from split power supplies is also
possible and the low power supply current drain is independent of the magnitude of the
power supply voltage.
Application areas include transducer amplifiers, DC gain blocks and all the conventional
op amp circuits which now can be more easily implemented in single power supply systems.
For example, the LM124 series can be directly operated off of the standard a5V power supply
voltage which is used in digital systems and will easily provide the required interface
electronics without requiring the additional g15V power supplies.
Unique Characteristics
In the linear mode the input common-mode voltage range includes ground and the output
voltage can also swing to ground, even though operated from only a single power supply
voltage. The unity gain cross frequency is temperature compensated. The input bias current is
also temperature compensated
Advantages
1. Eliminates need for dual supplies
2. Four internally compensated op amps in a single package
3. Allows directly sensing near GND & VOUT also goes to GND
4. Compatible with all forms of logic
5. Power drain suitable for battery operation
30
Features
1. Internally frequency compensated for unity gain
2. Large DC voltage gain 100 dB
3. Wide bandwidth (unity gain) 1 MHz (temperature compensated)
4. Wide power supply range:
5. Single supply 3V to 32V or dual supplies g1.5V to g16V
6. Very low supply current drain (700 mA) essentially independent of supply voltage
7. Low input biasing current 45 nA (temperature compensated)
8. Low input offset voltage 2 Mv and offset current 5 nA
9. Input common-mode voltage range includes ground
10. Differential input voltage range equal to the power supply voltage
11. Large output voltage swing 0V to Vab 1.5V
Fig. 6:Internal circuit diagram of LM324
31
5. VOLTAGE REGULATOR/7805
The 78xx (sometimes LM78xx) is a family of self-contained fixed linear voltage
regulator integrated circuits. The 78xx family is commonly used in electronic circuits
requiring a regulated power supply due to their ease-of-use and low cost. For ICs within the
family, the xx is replaced with two digits, indicating the output voltage (for example, the 7805
has a 5 volt output, while the 7812 produces 12 volts).
The 78xx lines are positive voltage regulators: they produce a voltage that is positive
relative to a common ground. There is a related line of 79xx devices which are
complementary negative voltage regulators. 78xx and 79xx ICs can be used in combination to
provide positive and negative supply voltages in the same circuit.
The 78xx ICs have three terminals and are commonly found in the TO220 form factor,
although smaller surface-mount and larger TO3 packages are available. These devices
support an input voltage anywhere from a couple of volts over the intended output voltage, up
to a maximum of 35 or 40 volts, and typically provide 1 or 1.5 amps of current (though
smaller or larger packages may have a lower or higher current rating).
ADVANTAGES
1. 78xx series ICs do not require additional components to provide a constant, regulated
source of power, making them easy to use, as well as economical and efficient uses of
space. Other voltage regulators may require additional components to set the output
voltage level, or to assist in the regulation process. Some other designs (such as
a switching power supply) may need substantial engineering expertise to implement.
2. 78xx series ICs have built-in protection against a circuit drawing too much power.
They have protection against overheating and short-circuits, making them quite robust
in most applications. In some cases, the current-limiting features of the 78xx devices
can provide protection not only for the 78xx itself, but also for other parts of the
circuit.
32
PIN CONFIGURATION
Fig. 7:Pin layout of IC7805
The above given TO-220 package is being used in our project, and is widely used in the industy.
The TO-220 is a style of electronic component package, commonly used
for transistors, silicon-controlled rectifiers, and integrated circuits. The "TO" designation
stands for "transistor outline". TO-220 packages have three leads. Similar packages with two,
four, five or seven leads are also manufactured. A notable characteristic is a metal tab with a
hole, used in mounting the case to a heat sink. Components made in TO-220 packages can
dissipate more heat than those constructed in TO-92 cases.
33
The TO-220 package is an example of a through-hole design rather than a surface-mount
technology type of package. TO-220 packages are heat sinkable, and thus can be used for
applications where large amounts of power are dissipated as heat. The top of the package has
a metal tab with a hole used in mounting the component to a heat sink. Thermal compound is
often applied to further improve heat transfer from the package to the heat sink.
The metal tab is often connected electrically to the internal circuitry. This does not
normally pose a problem when using isolated heat sinks, but an electrically-insulating pad or
sheet may be required to electrically isolate the component from the heat sink if the heat sink
is electrically conductive, grounded or otherwise non-isolated. Many materials may be used
to electrically isolate the TO-220 package, some of which have the added benefit of high
thermal conductivity.
In applications that require a heat sink, damage or destruction of the TO-220 device due
to overheating may occur if the heat sink is dislodged during operation.
Advantages:
• Can be used in high-power and high-current applications where equivalent
components of other cases may be susceptible to damage.
• Grounding area makes handling easier by reducing the possibility of damage
from electrostatic discharge.
• Mounting with the tab ensures the component to be held firmly in place.
34
INTERNAL BLOCK DIAGRAM
Fig. 8: Internal block diagram of IC7805
ABSOLUTE MAXIMUM RATINGS35
Table 5:Absolute maximum ratings of IC7805
The above given table shows the various parametric maximum ratings of the voltage regulator 7805.
A 5V voltage regulator (7805) is used to ensure that no more than 5V is delivered to the
board regardless of the voltage present at the J12 connector (provided that voltage is less than
12VDC). The regulator functions by using a diode to clamp the output voltage at 5VDC
regardless of the input voltage - excess voltage is converted to heat and dissipated through the
body of the regulator. If a DC supply of greater than 12V is used, excessive heat will be
generated, and the board may be damaged. If a DC supply of less than 5V is used, insufficient
voltage will be present at the regulators output.
If a power supply provides a voltage higher than 7 or 8 volts, the regulator must dissipate
significant heat. The "fin" on the regulator body (the side that protrudes upward beyond the
main body of the part) helps to dissipate excess heat more efficiently. If the board requires
higher currents (due to the use of peripheral devices or larger breadboard circuits), then the
regulator may need to dissipate more heat. In this case, the regulator can be secured to the
circuit board by fastening it with a screw and nut (see below). By securing the regulator
tightly to the circuit board, excess heat can be passed to the board and then radiated away.
36
6. VOLTAGE REGULATOR/7812
Voltage regulation means to prevent the voltage from dropping down or rising above a
specific value. A 12 volt regulator circuit will provide exactly 12V under load as well as
without load. On the other hand, an un-regulated 12V power supply output voltage with drop
under while the load will increase and will rise when not under load. For example, an un-
regulated 12V power supply can output 14V when not under load and can drop the voltage to
11V when under 1A load and 10V when under 2A load. This rise and drop of voltage in un-
regulated power supplies can sometimes burn sensitive electronics equipments.
FEATURES
1. Output current in excess of 1A
2. Internal thermal overload protection
3. No external components required
4. Output transistor safe area protection
5. Internal short circuit current limit
6. Available in the aluminium TO-3 package.
VOLTAGE RANGE
LM7805C 5V
LM7812C 12V
LM7815C 15V
37
PIN CONFIGURATION
Fig. 9: Top view of TO-220 packaging
Absolute Maximum Ratings
Input Voltage
(VO = 5V, 12V and 15V) 35V
Internal Power Dissipation (Note 1) Internally Limited
Operating Temperature Range (TA) 0°C to +70°C
38
7. Voltage Regulator/IC7815
Features
1. Output current in excess of 1A
2. Internal thermal overload protection
3. No external components required
4. Output transistor safe area protection
5. Internal short circuit current limit
6. Available in the 39luminium TO-3 package
7. V REG +15V, 7815, TO-220-3
8. Dropout voltage:2V
9. No. of Outputs:1
10. No. of Pins:3
11. Voltage Regulator IC Case Style:TO-220
12. Operating Temperature Range:-20°C to +85°C
13. Case Style:TO-220
14. Max Operating Temperature:85°C
15. Min Temperature Operating:-20°C
39
CHAPTER 4
BLOCK DIAGRAMS
Amplification Circuit The voltage signal of the thermocouple is usually in the milli-volts range, hence
amplification is needed. One of the most used amplifiers is the “instrumentation amplifier
[IA]” (or high impedance differential amplifier). Aside from amplification,
this IA has the potential to remove common mode noise. It is formed by three operational
amplifiers a shown in Figure 2 below. We will connect this circuit on the breadboard by
using the quad Op-Amp IC (LM324) to save wiring complexity.
Fig. 1: Amplification Circuit
40
The output of the amplifier is given as:
Connection of LM35DZ with the amplification IC LM324
Fig. 2: Connection of LM35DZ with the amplification IC LM324
The above diagram shows the circuit connection of the temperature sensor LM35DZ with
the amplification circuit comprising LM324, the output of which is fed to DAQ.
The resistor components used here are specifically designed to obtain a voltage gain to
drive the DAQ.
41
Connection of pressure sensor ICS 1220 with amplification IC LM324
Fig. 3: Connection of pressure sensor ICS 1220 with amplification IC LM324
The above diagram shows the connection of pressure sensor ICS 1220 with amplification
IC LM324. The circuit components like resistors are arranged in a manner so as to obtain a
proper voltage gain to drive the DAQ.
The operational amplifier used here is IC741 the output of which is fed to the sensor. The
output of the sensor is fed to the amplification circuit comprising resistors and LM324.
42
CHAPTER 5
LabVIEW
LabVIEW is a graphical programming environment used by millions of engineers and
scientists to develop sophisticated measurement, test, and control systems using intuitive
graphical icons and wires that resemble a flowchart. It offers unrivalled integration with
thousands of hardware devices and provides hundreds of built-in libraries for advanced
analysis and data visualization – all for creating virtual instrumentation. The LabVIEW
platform is scalable across multiple targets and OSs, and, since its introduction in 1986, it has
become an industry leader.
Key Features
1. Faster Programming
2. Hardware Integration with LabVIEW
3. Advanced Built-In Analysis and Signal Processing
4. Data Display and User Interfaces
5. Multiple Targets and Oss
6. Multiple Programming Approaches
7. Multi core Programming
8. Data Storage and Reporting
9. Software Services, Training, and Support
10. File Sharing and Collaboration with LabVIEW Users Worldwide
43
Data Acquisition
Designed for performance, NI data acquisition (DAQ) devices provide the I/O
capabilities, measurement accuracy, and software flexibility your application requires. With
patented hardware and software technologies, National Instruments offers PC-based
measurement and control solutions that deliver increased productivity through user-defined
logging, analysis, and visualization.
Choose from a variety of common PC-buses and form factors, including USB, PCI, PCI
Express, PXI, PXI Express, wireless, and Ethernet. NI-DAQmx multithreaded driver
software provides ease of use, flexibility, and performance in multiple programming
environments, including NI LabVIEW, NI LabWindows™/CVI, C/C++, Visual C#, and
Visual Basic .NET.
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NI USB-6008
14-Bit, 48 kS/s Low-Cost Multifunction DAQ
1. 8 analog inputs (14-bit, 48 kS/s)
2. 2 analog outputs (12-bit, 150 S/s); 12 digital I/O; 32-bit counter
3. Bus-powered for high mobility; built-in signal connectivity
4. OEM version available
5. Compatible with LabVIEW, LabWindows/CVI, and Measurement Studio for Visual
Studio .NET
6. NI-DAQmx driver software and NI LabVIEW Signal Express LE interactive data-
logging software.
7. 8 analog inputs (14-bit, 48 kS/s).
8. 2 analog outputs (12-bit, 150 S/s); 12 digital I/O; 32-bit counter.
9. Bus-powered for high mobility; built-in signal connectivity.
10. OEM version available
11. Compatible with LabVIEW, LabWindows/CVI, and Measurement Studio for Visual
Studio .NET
12. NI-DAQmx driver software and NI LabVIEW SignalExpress LE interactive data-
logging software
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NI USB-6008
Internal Diagram:
Fig. 1: NI USB-6008
Shown above are the front view and the side view of the USB 6008. The width excluding
the ports is 63.5mm, and the width of the USB 6008 including the ports is 72.65mm.
The lengths are 76.0mm and 85.09mm.
In inches, the width excluding the ports is 2.500 inches, and the width of the USB 6008
including the ports is 2.860 inches.
The lengths are 2.996 inches and 3.350 inches.
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LabVIEW Codes
Block Diagrams:
Part 1.
Fig.2:Creationo of sender’s email id
Figure2 shows the first part of the block diagram. This includes the creation of the sender’s e-
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mail address, the receiver’s email address, the case structure including if or not a cc is to be
sent. It also includes the merger of the subject and the body.
Part 2
Fig. 3:Activation of SMTP
Figure 3 shows the second part of the block diagram. It includes activating the Simple Mail Transfer Protocol (SMTP).
It also includes the coding used for attaching a file along with the message. The meteorological data can be sent in that file.
Part 3
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Fig.4: Storing data in the file
In figure 4, the meteorological data is stored in the file. Depending on the Boolean switch, the file is either written or sent.
Part 4
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Fig.5: Acquiring the signals and filtering
In Figure 5, the parameters to be measured are acquired, filtering is done, and the parameters are stored in an array, and shown graphically.
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Front Panel of Data Logger
Fig. 6:Front Panel depicting Controls and Indicators
As shown in fig.6, the front panel comprises indicators like temperature indicator, pressure
indicator, humidity indicator. The graph and chart for temperature and humidity are drawn with
respect to time.
A dialog box is given for Sender’s Email address, to which the data is being sent.
A dialog box depicting the port number is meant for a particular website on which the email
account is created. The port number varies according to the website. Here, we are using Port
number 587 which is specifically defined for Gmail.
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DAQ ASSISTANT
In order to make things easier, National Instruments have create a subVI that aids us in
configuring data acquisition devices and/or sensors. This subVI is called the “DAQAssistant
subVI”. In order to work with it, right click on the block diagram, then go to “Measurement
I/O”, then go to “DAQmx Data Acquisition”, then go to “DAQAssistant”.
When DAQ is placed in the block diagram, a series of pop-up windows provides the
medium to create and configure DAQmx tasks.
Fig. 7:Selecting the measurement type
In Fig.7, a number of input/output options like analog input, analog output, counter input,
counter output and digital input/output are shown.
We select the measurement type for our task.
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Fig 8:Selecting the measurement type
In fig.8, a number of analog inputs like temperature, voltage, strain, current, resistance,
frequency, position, acceleration, custom voltage with excitation and sound pressure are given.
We select the measurement type required for our task.
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Fig. 9: Type of sensor
In fig. 9, we are provided the options of the type of sensor we are using. In the temperature
section, we have thermistor, RTD, thermocouple or Vex Thermistor to measure the temperature.
Our requirement is thermistor, so we select the thermistor option.
Thermistor is the temperature sensor in which there is a negative temperature co-efficient,
that is, the value of the resistance decreases with an increase in temperature.
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Fig. 10: Selecting analog channel
As shown in figure 10, we select the analog channel required for our purpose.
We select the virtual channel to add to our task.
The analog channels from ai0 to ai7 are those that are similar to the physically defined ports
on USB 6008.
The above given steps are defined in points in the following page. The steps include
everything from selecting the measurement type to clicking finish.
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• Select Measurement Type
• Select Analog Input
• Select Temperature
• Select Thermistor
• Select ai0 associated with “Dev1” then
• Select Next. A new dialogue box appears to assign a name to the task.
• Assign a name and
• Select Finish
At this point, the DAQ Assistant opens a window which displays the options for configuring
the selected channels. The Settings tab allows setting of the input range and the Task Timing
tab selects the number of samples.
At this point you can click the Test button to access the Analog Input Test Panel dialog
box to test the channel by clicking on the Start button. Once done, click OK to return to DAQ
Assistant window. Click OK again to return to the block diagram. Once there, right click on the
Data output of the DAQ Assistant Express VI and select Create >> Graph Indicator.
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CHAPTER 6
COMMUNICATION
SMTP
Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail)
transmission across Internet Protocol (IP) networks. SMTP was first defined by RFC 821 (1982,
eventually declared STD 10), and last updated by RFC 5321 (2008) which includes the extended
SMTP (ESMTP) additions, and is the protocol in widespread use today. SMTP is specified for
outgoing mail transport and uses TCP port 25. The protocol for new submissions is effectively
the same as SMTP, but it uses port 587 instead. SMTP connections secured by SSL are known
by the shorthand SMTPS, though SMTPS is not a protocol in its own right.
While electronic mail servers and other mail transfer agents use SMTP to send and receive
mail messages, user-level client mail applications typically only use SMTP for sending
messages to a mail server for relaying. For receiving messages, client applications usually use
either the Post Office Protocol (POP) or the Internet Message Access Protocol (IMAP) or a
proprietary system (such as Microsoft Exchange or Lotus Notes/Domino) to access their mail
box accounts on a mail server.
SMTP is a text-based protocol, in which a mail sender communicates with a mail receiver by
issuing command strings and supplying necessary data over a reliable ordered data stream
channel, typically a Transmission Control Protocol (TCP) connection. An SMTP session
consists of commands originated by an SMTP client (the initiating agent, sender, or transmitter)
and corresponding responses from the SMTP server (the listening agent, or receiver) so that the
session is opened, and session parameters are exchanged. A session may include zero or more
SMTP transactions.
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An SMTP transaction consists of three command/reply sequences (see example below.)
They are:
MAIL command, to establish the return address, a.k.a. Return-Path, 5321.From, or envelope
sender. This is the address for bounce messages.
RCPT command, to establish a recipient of this message. This command can be issued
multiple times, one for each recipient. These addresses are also part of the envelope.
DATA to send the message text. This is the content of the message, as opposed to its
envelope. It consists of a message header and a message body separated by an empty line.
DATA is actually a group of commands, and the server replies twice: once to the DATA
command proper, to acknowledge that it is ready to receive the text, and the second time after
the end-of-data sequence, to either accept or reject the entire message.
CHAPTER 7
FUTURE ENHANCEMENTS
In our project, we have successfully acquired meteorological data from the atmosphere
and recorded, analysed and communicated them.
We can use GSM technology to communicate the data to a cellular mobile phone via
Short Messaging Service. If applied, this means that as soon as the data is recorded, a mobile
phone whose number is stored in the program will receive a text message intimating all the
details comprising data.
The interfacing can be improved by using Compact RIO. The program can be stored in
RIO and it can act as a standalone device. This will ensure a higher speed.
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CHAPTER 8
CONCLUSION
For many important experiments that are conducted at national and international levels
in various scientific and technical establishments for research, environmental and
meteorological data is necessary. There are many ways in which such data is acquired. We
have used the software LabVIEW by National Instruments to collect data, i.e. temperature,
humidity and pressure, to log this data and analyse it in different ways. The data acquired on
site has to be transmitted to the workplace, where research experiments are conducted. We
have programmed our project to transmit the data using SMTP. Thus, our project acquires,
analyses, and transmits important data that can then be used for making important
breakthroughs.
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