FPGA Implementation of Real time monitoring system for Agricultural and Green house fields

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27 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

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FPGA Implementation of Real time mon
i
toring system for Agricultural and

Green house fields

M.Jeyaprakash
,

Dept of ECE
,

Chettinad College of Engg & Tech
,


Karur, India.

vlsijp@gmail.com
.



Abstract

This

paper presents the VLSI implementation of
real time
monitoring
of
agricultural parameters like
temperature, humidity and light intensity.

The most important
factors for the quality and productivity of plant growth are
temperature, light, and the level of
the
carbon

dioxide.
Continuous monitoring of these environmental variables gives
info
rmation to the grower
understand

better
, how each factor
affects growth and how to m
anage maximal crop productivity
.
This system utilizes VLSI technology for data collecti
on and
processing
.

Keywords
-
VLSI, FPGA, VHDL
, XILINX

I.


I
NTRODUCTION

India is an ag
riculture

oriented country. T
he quality and
Product
ivity improvement of agricultural crops and Green
house plants are inevitable. It
is necessary to measure and
control several interacting physical variables. These tasks
can
only be accomplished by Electronic systems and
software.

Automation machinery is imported in India hence
it is expensive. Many farmers cannot adopt the greenhouse
t
ech
nology due to its high cost. This paper

highli
ghts about
the approach to measure and control of agricultural field in
enhanced manner. The implemented system

senses the
changes in the temperatures, humidity, light intensity (Dry
temperature, Wet tempera
ture) through input sensors.

Real time monitoring provides reliable, timely
information of crop and soil status
. It is vital in taking
decisions for crop production improvement. Humidity,
temperature and light intensity are the main physical
parameters in
fl
uences the crop cultivation.[3
-
5
]. There are
methods which adopts electronic systems and techniques to
measure the above said parameters

[1
-
2]
.

Here the proposed method uses the low cost and high
performance electronic devices (FPGA) for the measurement
and control purpose. These FPGA devices are reconfigurable
and well suited for prototyping.

This paper presents system architecture in Section
II and
in Section III implementation

results. Section IV concludes
this paper.

II.

SYSTEM ARCHITECTURE

The proposed
system in this paper has three main
modules: sensor, signal

conditioning and control unit.
Sensors used to measure temperature; humidity and light
intensity are in the sensor module.

Figure 1.

System architecture

The outputs of sensor modules are given
the signal
conditioning circuit. Here the amplitude of sensor output
signal
s are in low levels. It should be amplified then only it
can processed in further stages. Op
-
amp based amplifier
circuit will serve the
purpose,

and then

it has been converted
into
digital signal using ADC. The digital output of signal
conditioning module is the essential and desirable form for
the control unit. The
important

role of the sensor module
and signal conditioning is the co
ntinuous monitoring of the
field and supplying si
gnal to control unit. The control unit is
the heart of this system. It has been implemented in VLSI.
The FPGA device was chosen for the control unit. Control
unit will process signal conditioned signal and display the
values. The control and processing has

been design using
VHDL and synthesized in XILINX tool
[9]
.
Control unit can
also
send the data to the host PC through GSM/GPRS
MODEM

through serial port.

In that case this entire system
will be treated as a remote unit. Further the host PC can
communicate
and send control signal to this FPGA unit.
Based
on the control unit, the FPGA device will take some
corrective measures.

This entire remote unit will be on single board and
powered by a battery supply.
This may be a wireless unit for
data collection. The

FPGA device can perform as a efficient
control and processing unit.

III.

IMPLEMENTATION

RESULTS

a)

Temperature unit



Figure 2. Temperature sensor


The LM 35 sensor is used for temperature
measurement. The implemented circuit is shown in Fig. 2.

Temperature for plant (flowers & vegetables) growth
required is 26ºC
-

30ºC in day time and 15ºC
-

18ºC in night
time. The operating temperature of LM 35 sensor is upto
150ºC
. so it is well suited for requirement of this design.

b)

Humidity unit


Figure 3. H
umidity sensor


Humidity module used here is SY
-
HS
-
220.
Humidity

is the amount of water vapor in an air sample.
There are three different ways to measure humidity:
absolute humidity, relative humidity, and specific humidity.
Relative humidity is the most f
requently encountered
measurement of humidity because it is regularly used in
weather forecasts.

It’s an important part of weather reports because it
indicates the likelihood of precipitation, dew, or fog. Higher
relative humidity also makes it feel hotte
r outside in the
summer because it reduces the effectiveness of sweating to
cool the body by preventing the evaporation of perspiration
from the skin. This effect is calculated in a heat index table.
Warmer air has more thermal energy than cooler air thus
more water molecules can evaporate and stay in the air in a
vapor state rather than a liquid state.


c)

Light intensity mesurement

















Figure:4

LDR circuit


For proper growth of plants in greenhouse required
light intensity should be around 50,000 to 60,000 LUX is
needed. Light intensity in India is around 40,000 to

1,40,000 LUX. Thus using shade nets we have to reduce
this light intensity.
Two cadmium supplied (cods)
photoconductive cells with spectral responses similar to that
of the human eye. The cell resistance falls with increasing
light intensity.


Applications include smoke detection, automatic
lighting
control;

batch counting and bu
rglar alarm
systems.

An

LDR and a normal resistor are wired in series across a
vol
tage, as shown in the figure
-
4
. Depending on which is
tied to the 5V and which to 0V, the voltage at the point
between them, call it the sensor node, will either rise or fall

with increasing light.


If the LDR is the component tied directly to the
5V, the sensor node will increase in voltage with increasing
light. The

LDR's resistance can reach 10 kΩ in dark
conditions and about 100 ohms in full brightness. The
circuit used fo
r sensing light in our system uses a 10 kΩ
fixed resistor which is tied to +5V. Hence the voltage value
in this case decreases with increase in light intensity


d)

ADC & FPGA Module

ADC0805 has been used for converting the analog signal
to digital signal and
interfac
ing with the FPGA. XILINX

XC3S100E


i
s the t
arget device. The VHDL coding i
s
downloaded in the FPGA device to process the digitized
signals. The incorporated LCD will display the values.


IV.

H
ARDWARE IMPLEMENTATI
ON




Figure 5. Hardware implementation


The proposed system for real time monitoring of
agricultural filed has been discussed in earlier. The Fig.5
shows the hardware module of the system. It is prototype
model. Using Xil
inx tool the VHDL program was dumped
into the FPGA.




Figure 6. LCD Display of Values


The LCD module displays the monitoring parameters.
Power supply, humidity module, temperature module and
Light intensity module all has

been

incorporated.

V.

CONCLUSION AND FUTUR
E SCOPE

The FPGA based system was developed and tested for
the data acquisition on the agricultural fields. The measured
parameters were displayed on the LCD. In future this FPGA
module can be integrated with GSM/GPRS modem, so that
it

is possible to send data to host pc. This system then will
act as a remote unit. The hosts PC further analyze the data
and accordingly may send a control signal to the remote
unit.


R
EFERENCES

[1]

Wael M El
-
Medany, “Fpga implementation for Humidtity and
Temperature remote Sensing system,” IEEE Xplore 200
8

[2]

Wael M El
-
Medany,

GPRS
-
based remote sensing system for
humidity and temperatur using coolrunner
-
2 CPLD

, computing
online.net

[3]

O
.

Korner, H. Challaw, “Temerature integration and process based
humiditiy
control in chrysanthamum:, Computers and Electronics in
Agriculture V43, PP. 17
-
21, 2004

[4]

J.C. Bakker, “Analysis of humidity effects on growth and production
of glass house fruit vegetables”, Ph.D. thesis, Wageningen
Agricultural University, Wageningen, P.
155, 1991.

[5]

H.R. Gislerod, P.E. Nelson, “The interaction of relative humidty and
CO2 enrichment in the growth of Chrysanthemum”, Ramat. Scientia
Hotculturae 38, PP. 305_313, 1989

[6]

Douglas L. Perry, VHDL programming by example.

[7]

Volnei A. Pedroni, Circuit des
ign with VHDL

[8]

www.analog.com

[9]

www.xilinx.com