Implementation of Controller
The main aim of this work is to save the water, electricity and improve the growth of plant. Considering farmer’s economical conditions we have prepared a circuit which is cheap and reliable. We have used 89C52 microcontroller for low consumption, low cost, small circuit size and easy to implement. Micro controller can read the data available at o/p of A/D converter and store in memory and compare with the set point to turn ON or OFF relay If comparison is equal then operate relay [6]. 12 MHz quartz ceramic crystal is connected between pin XTAL and XTAL of micro controller to produce machine cycle for fetch and execution of instruction. And at pin 9 RST pin we connect R.C n/w to provide reset pulse when power is turn on so that program execution starts from memory location 0000H. For our all IC we require 5 v D.C., +12vdc,-12v dc supply which can be generated by step down transformer, full wave bridge rectifier, filter condenser and voltage regulator IC.