Engineer Dissertation


п»їMonitor and Control of Green House Environment


The suggested project can be an inserted system that can closely keep an eye on and control the microclimatic parameters of any greenhouse regularly round the clock for cultivation of crops or specific herb species which could maximize their very own production over the whole crop growth time and to lowering human intervention to the best suited extent in the existing system. This system comprises of sensors, unaggressive components, microcontroller, Analog-to-Digital Convertor (ADC) and actuators.

When any of the previously discussed climatic variables cross a security threshold which includes to be managed, the transducers sense the change and the microcontroller says this from your data at its input slots after being converted to an electronic digital form by ADC. The microcontroller after that performs the needed actions by employing relays until the strayed-out parameter has been restored to its ideal level. Right here the microcontroller is used while the cardiovascular of the program; which makes the set-up very cheap and nevertheless effective. While the system likewise employs an LCD to get continuously showing the condition inside the greenhouse, the complete set-up becomes user friendly. Thus, this system reduces the disadvantages of the existing system stated previously and design is not hard to maintain, flexible and inexpensive.


1 . Power Unit

2 . Sensors (Data acquisition system)

a) Temperatures sensor (LM35)

b) Mild sensor (LDR)

c) Water sensor

d) Humidity sensor (HIH 4000-001)

3. Microcontroller (AT89S52)

4. Liquid Very Display



The strength supply Device consists of step down transformers, Full wave rectifier, filtration systems and volts regulators. The step down transformer of 230V major step throughout the voltage to (+5V to 0V) and +12V to 0V) second voltages. The stepped straight down voltage is then rectified (Converted from ALTERNATING CURRENT to DC) by the 4 1N4007 diodes configured to form a full influx rectifiers. The high value of capacitor 1000ОјFcharges at a slow rate since the time regular is low. This gives a continuing value of DC on the rectifier end result. IC 7805 is used intended for regulated availability of +5 volts and IC 7812 is utilized to provide a regulated supply of +12 volts to be able to prevent the outlet ahead from any fluctuations. The filter capacitors 10ОјF and 1ОјF connected between the output and the ground in the voltage regulator filters the high frequency spikes and also gives stability towards the power supply circuit.


A transducer is a system which turns one type of a signal/energy intoother signal/energy which can be processedfor observation or for way of measuring.

Soil Dampness Sensor

This kind of sensor can be chosen depending on its ability to withstand hash conditions and it laxness. The sensor circuit can be design about an NPN 2N222 transistor operating in 5Vdc, a100О© fixed resistor a 10kО© variable resistor and two copper prospects that act as the messfuhler probes. The fix resistor is born in series with the bottom terminal and voltage source to limit excess current from the ac electricity source while the variable resistor is used to modify the sensitivity of the sensor The transistor is designed in a ahead biased modeand therefor adequate enough voltage present at the basic will cause the present held on the collector passageway to circulation through the emitter terminal towards the ground and therefor some voltage will probably be present in the emitter fatal. This volts present on the emitter can be directly proportionate to the volts present with the base terminal. When the probes are engrossed into the example of beauty soil in whose moisture articles is to be watched, the voltage output of the transistor is directly proportional to the conductivity of the ground. Since the conductivity of soil depends upon the quantity of moisture present in it and it raises with embrace the water articles of the ground. The ground is...