Advanced switching

Advanced Switching CELLPHONE CONTROLLED 220V AC SWITCH BY: ADITYA KUMAR

Introduction:

1) Cellphone controlled switch is a machine that can be controlled with a mobile. 2) In the course of a call, if any button is pressed, a tone (DTMF) corresponding to the button pressed is heard at the other end of the call. 3) The device perceives this DTMF tone with the help of the phone stacked on it. 4) The received tone is processed by the microcontroller with the help of DTMF decoder. 5) The microcontroller then transmits the signal to the BJT to operate the RELAY & our AC supply is ON/OFF.

Project Overview:

1)The device is controlled remotely using two cellphone one is stacked on device and another one is used as remote.2) Main circuit consist of many electronic chips that are: a) Microcontroller ATMEGA16 b) MT8870 c) IC 7805 d) IC74LS04 e) NPN Q2N22

a) MT8870 is used here to receive the DTMF tone and generate corresponding 4 digit binary code. b) 74LS04(NOT Gate IC) is used for Quality resolution of the signal recived at DTMF decoder.c) Microcontroller ATMEGA16 is programed to take binary input and give corresponding output.d) This output works as input for npn Q2N22(BJT) that is made to work as switching device.e)Output of BJT is given to relay that is operated with 5V dc providing 220V AC switching.

Basic Block diagram of device

Atmega16 & MT8870 IC’s:

Elements used: (resistors,capacitor,bjt,crystal oscillator,relay)

Block Diagram Of Circuit

Working of switch:

1) In order to control the switch, you have to make a call to the cellphone attached to the device.(which is in auto answering mode).2) Now when you press 2 bulb1 will be ON (as programmed).3) When you press 4 bulb 2 will be ON(as programmed).4) Now when you press 6 bulb1 will be OFF (as programmed).5) When you press 8 bulb 2 will be OFF (as programmed).6) When you press 5 all supply will be OFF.

Programming behind the operation:

Software Used:

1) Atmel studio 6.1 (for hex coding) 2) Flash tool (for program writing)3) Proteus 8 professional (for circuit design)

Application:

1) Home appliances control.2) Control of home windows and shutters.3) Home entertainment system.4) Security system.5) Many other connectivity purposes.

Advantages:

1) Simple and easy to access.2) Access from remote area.3) Low power consumption.4) Taking measures to reduce electricity bill.5) Portability.6) Cost efficient.

Future Enhancement:1) It can be used as :a) Controlling speed of fanb) Controlling room temperaturec) Recording our favorite TV program when we are outside from our home.2) It can be used for security proposes. 3) For many other connectivity purposes.

Conclusion:

1) This document presents a mobile controlled and user friendly approach towards better connectivity.2) This system can be easily implemented because of its wireless communication standards.3) Many of the remote controlled application can be esily done using this technique.