Greenhouses Environment Control System form an important part of the agriculture and horticulture sectors in our country as they can be used to grow plants under controlled climatic conditions for optimum produce. Appropriate environmental conditions are necessary for optimum plant growth, improved crop yields, and efficient use of water and other resources. Automation is process control of industrial machinery and processes, thereby replacing human operators. The soil moisture conditions, environment temperature and various climatic parameters govern plant growth. Automating the data acquisition process allows this information (soil moisture, temperature and various climate parameters) to be collected at high frequency with less labor requirements.
Our main focus in this project is to design a simple, easy to use, micro – controller based circuit which monitor and record the values of temperature, humidity, soil moisture and sunlight of the natural environment that are continuously modified and controlled. This helps in achieve maximum plant growth and yield. We use in this circuit a low power, cost efficient chip manufactured by ATMEL AT89S52.
It communicates with the various sensor modules in real-time in order to control the temperature, soil moisture, humidity and day light inside a greenhouse by actuating a cooler, water pump, sprayer and lights respectively according to the necessary condition of the crops. There is a 16×2 character LCD is also used for displaying the information getting from various sensors. This project provides economical, portable and a low maintenance solution for greenhouse environment.
For power supply in the “Greenhouse Environment Control System” to provide 5V and 12V, the circuit consists of step down transformer of 230/12V. This transformer steps down 230V AC from main supply to 12V AC. Then that 12V AC is converted into 12V DC with the help of bridge rectifier. After that a 1000/25V capacitor is used to filter the ripples and then it passes through voltage regulator. There are two power supply arranged in same manner one containing 500mA transformer and second has 750mA transformer.
This project comprises of sensors, Analog to Digital Converter (ADC), Micro – controller AT89S52, Relay driver IC (ULN2003), Relays, 16×2 characters LCD and a buzzer. The AT89S52 micro – controller is as the heart of the system, it makes the set-up low-cost and effective nevertheless. Each sensor gives their measured parameter found to the micro – controller through ADC after being converted to a digital form. When any one of the parameter read by the controller crosses a safety limitation which has to be maintained for protection of the crops, then micro – controller performs the required actions by employing relays until the strayed-out parameter has been brought back to its optimum level. There is a LCD display which displays all the information of four sensors. At each update of controller there will be a sounds buzz for indication of updating.