This paper addresses a new technology in the field of control systems; due vast expansion of Embedded Systems in the development of control systems had made the modern controlling techniques simpler, embedded systems are the auxiliary system which is closely related to the original system either directly or indirectly connected to the main system, these embedded systems uses a micro computer or an micro processor, meeting the immense computing needs to perform the  tasks efficiently at a minimum cost, various controlling strategies were implemented without direct involvement of humans.

In our project a micro controller based multiple device control systems using single switch, these microcontroller had found multiple applications in the fields of security, medical sciences,  determining whether conditions,

 In our project 12v supply is derived from 230v supply by using a transformer,  this 12v output is converted into pulsating dc by using an bridge rectifier and feed to the filter this filter removes the unwanted  ripple content and produced 5v constant DC voltage.  

This rectified DC current is feed to the micro controller and then to potentiometer, this output of the potentiometer is given to the analog to digital converter of the PIC16F872 microcontroller which had capability to perform controlling operations on nearly 256 devices at a time.

The LCD devices operate based on the relay circuit on and off positions, the entire 256 devices are divided into four parts and hence the output terminals are 64 starting from 0-63,  a crystal oscillator is used generate control signals for the microprocessor, along with the control button used to represent the on and off conditions of the device.

When compared to conventional manual operations this microcontroller based control strategies are very useful in maintaining accuracy, saving time and man power, these devices are cheaper and highly reliable with less complexity.

The practical calculations had revealed that this circuit can control multiple devices at a time without the scope of errors and malfunctions 

Download  Microcontroller Based Multiple Device Control Based On Input Frequency Project Abstract.