This document discusses the use of data loggers and sensors in a dew and rainwater harvesting project in India. It describes: 1) How various sensors are installed to collect meteorological data like temperature, humidity, wind speed and direction. The sensors are wired to a data logger for storage. 2) The data logger stores measurements from the sensors and can access the data remotely using MODBUS communication. It converts analog sensor readings to digital for storage and display. 3) Tests were conducted to successfully access sensor data from the data logger remotely using MODBUS protocol and software. This allows monitoring of climatic conditions for managing water resources.

1. ROLE OF DATA LOGGER AND SENSORS
IN
DEW AND RAIN WATER HARVESTING SYSTEM
NEAR KHOTARA

2. Introduction:
The role and science and technology in developing
countries not only help in understanding the problem
but also paves a way to solving the problems. In
country like INDIA were most of the population lives
in rural areas are encircled by various problems and
challenges. Among such challenges are water and
electricity. In order to find a solution to this problem
by the help of science and technology a village region
“Kohtara” was selected to do a project in Bhuj district
of GUJARAT state. A Dew and Water harvesting
system was a novel approach undertaken by Professor
Girja sharan to tackle the water problem in Semi-Arid
regions and to show how science can play a role to
eliminate this problem.
Motivation:
I being an ICT student found a chance of role of
Technology and Devices into the project. The main
motivation that keeps me to drive into the project is to
solve the problem of acquiring the meteorological data
by the help of different devices and various
technologies available in science world. The data that
collected is a meteorological information which could
be helpful for understanding various climatic changes,
it also helps for making decision for future purpose.

3. Approachment of Devices and Technology:
The acquiring of data at the project site is done by
the requirement levels. The project is more interested
into the “Surface temperature, Wind direction, Wind
speed, Air Temperature”, even though they are many
parameters of dynamic climate like Radiation, Rain
and Humidity so on. Due to the requirement and
concern interests the approachof devices is done on the
basis of project need. To acquire the meteorological
data “Sensors” are the best devices which can collect
the data scientifically and can transmit to the storage
devices. For this purpose Wind direction sensor, wind
speed sensor, ambient temperature sensors and relative
humidity sensor serves the purpose.
After the collection of the meteorological data from
sensors the storage of the data is maintained by the
Data Logger. The role of data logger is immense for
data collecting and storing with help of memory cards.
OBJECTIVES:
1) To suggest and install best method of collecting the
data about climatic changes from sensors and devices.

4. 2) To understand and observe the MODBUS device
along with data logger which can help in accessing
the data remotely.
3) To collect and analysing the data that collected on
the project site.
Step 1:
The best methods suggested of the networking of
sensors and data logger which used for collection of
data are:
a) Wired sensors – Wired data logger to base Station.
b) Wired sensors – Data logger with SD card.
c) Wired sensors – Wireless data logger.
d) Wireless sensor – Wireless data logger.
e) Wireless sensors with built in memory and TX/Rx.
By the project requirement and availability of funds
we choose the third model were the installation of
wired sensors and data logger with wireless
capabilities are carried for the project.
Wired Sensors:
The sensors which are mentioned in the project are
copper wired type which are connected to the

5. “Transporting Unit (T.U)”. This T.U act as bridging
between the sensors flow of data to the data logger
were Analog to digital data conversion are done.
Data Logger:
This device is reliable, accurate device and act as
instrument to record measurements of sensors. This
device consists of battery pack which provide power to
the device. This data logger is a microprocessor based
system that scans the input for every five seconds and
the analog data is multiplexed through an analog
multiplexer and converted to digital data by a 12 bit
analog to digital converter.The digital data is displayed
on a two line alphanumeric liquid crystal display. Data
logger consists of keyboard on the front panel which
can be given as input request. Along with data of
sensors, time and calendar can be set with help of
keyboard.

6. Installing the sensors:
Figure 1: The air temperature and humidity sensors
Figure 2: The air temperature and humidity sensors

7. Installing Data Logger:
Figure 3: Data logger installed in the site location
Figure 4: Data logger, battery, Translational unit

8. The above figure:1 and figure:2 depicts the sensors
position in the project area. The sensors are connected
with wired mode to the data logger. The data logger can
be seen with battery pack in the figure:3 and figure:4.
The data can be accessible from print pin in which a
SD card reader is connected with a 2GB card.
Brief description on “Data logger and
Modbus”:
Data Loggers are electronic devices which logs data
from other peripherals connected to it. Mainly data
logger are used for weather monitoring situations
alongwith sensors. Theyalso record the date andtime
with respective to sensor data.
PROJECT DETAILS:
For “Dew and Rain water Harvesting” project Data
logger play a pivotal role in understanding the weather
changes in semi-arid area. In order to access the data
remotely from data logger a device MODBUS is
embedded with data logger. As per the project
requirement Wind direction, wind speed, Temperature
sensors are used for observing the meteorological
changes.

9. Workingof Data logger and Sensors:
As seen in figure:1 the sensors of wind direction, wind speed
and temperature are connected to data logger by the wired cables.
The data logger consists of input port pins which provide
accessing of all data from sensors. Data loggers also contains two
output ports, one provide data of sensors in ‘.text’ format by
external memory card. The other port is a RS-485 which provide
current data. In order to read data from RS-485 on any computer
the data from RS-485 is given to RS-232 convertor.
This convertor had an established series connection with
computer. After installation of serial port drive software in
computer it is possible to detect the data from RS-232 convertor.
By the help of simulating software the output of the data can be
seen on the computer. Q Modbus master and Adam Apax.Net are
two types of software used for setting up the function code and
testing the sensor data.

10. Figure: 1
TEST SETTING UP:
As seen in figure: 2, After connecting with RS-485 to RS-232
convertor Through setup option the mode of error checking, baud
rate, data bits is selected for running the test. As seen in Figure 3:
the function code is selected. According to the project objective
reading the data from sensors is primary motive. So, the registers
which act as data holders are able to read by the function code:
Reading Holding Registers. After selection of function code the
type of data is selected in decimal or hexadecimal format.

11. Test Setup-Figure: 2
TEST FUNCTION CODE: This step provides to access the data
from registers in Hex and decimal form.
Function Code- Figure: 3
TEST RESULTS:
After selecting the test setup and function code the output
of the simulator will look as shown below figure-4

12. TEST RESULT FIGURE: 4
While observing the test results we can find the data is in
hexadecimal form and the number of the registers which means
the sensors data can be seen serially. But there are 10-errors in the
result that can be seen in right bottom of the screen shot. This is
because the wrong selection of RTU mode. From Figure:2 we
selected COM 4 but while selecting function code the setup is
disturbed by re-plugin, at that moment the software selected the
available COM 3 or COM 2. This leads to the error probability in
the results.
After correcting the set-up code and function code the error is
corrected by changing the sections. NOTE: This time the set-up

13. code is detected the COM: 3 and type of data is selected decimal
form. The results can be seen in the below figure: 5
FIGURE: 5
After running the test simulator the decimal form of data can be
seen in below Figure: 6 the test results show the decimal form of
data without any errors.
By using MODBUS and ARDUINO the objective of the

14. project is to access the data remotely. For this purpose the
MODBUS take the part of the data by providing the current data
by regular intervals as wanted by the user.
TEST RESULTS FIGURE: 6
Upgrading with modbus it will act as masters and sensors
act as slaves. By the request of the master the sensors check the
code to which sensor it is addressed andlater those sensors only
responds or acknowledges to the master by sending the data.
The function of ARDUINO and the handling of remotely
transmitting data by GPRS can be describe in next part.