A REMOTE CONTROL SYSTEM FOR HOME AND OFFICE APPLIANCE USING CELL PHONE

Presentation on A REMOTE CONTROL SYSTEM FOR HOME AND OFFICE APPLIANCE USING CELL PHONE

INTRODUCTION:

Devices connected as home and office appliances should be controlled as well as turn on /off if required Most of the times it was done manually. Now a day it is a necessity to control devices more effectively efficiently at any time from any where.

In this project I am going to develop a cellular phone based home/office appliance controller. To active the cellular phone unit on the system a call is to be made and as the call is answered, in response the user would enter a two/three digit password to access the system to control devices.

OBJECTIVES:

1. To develop a system so that it can be controlled by wireless devices and in turn it controls the home appliances connected to it.
2. Develop a system capable of remote access, and saving power by proper controlling devices.

Home and office appliances control by the system

Figure1: Devices connected as home &office appliance controlled by the system

Functional requirements:

The following is a list of functional requirements of the control unit/module.

1. The control unit will have the ability to connect to the cellular network automatically. The control unit will be able to receive DTMF and will be able to for password identification and instructions to be sent to the microcontroller.
2. The microcontroller within the control unit will issue its command to the electrical appliances through a simple control circuit.
3. The control unit will control the electrical appliances and detect the status of the appliances to be relay back to the microcontroller.
4. The system should provide user authentication through cell phone number identification and/or password verification contained within DTMF.

FUNCTIONAL BLOCK DIAGRAM:

Figure 2: Functional block diagram of the system.

METHODOLOGY FLOW CHART

Figure 2: Methodology flowchart

DTMF DECODING BY MT-8870

The MT8870D monolithic DTMF receiver offers small size, low power consumption and high performance. Its architecture consists of a band split filter section, which separates the high and low group tones, followed by a digital counting section which verifies the frequency and duration of the received tones before passing the corresponding code to the output bus.

DECODING OF DTMF BY MT-8870

Figure 3: DTMF Decoding by a dedicated DECODER IC MT-8870

Microcontroller issues command to control devices

After proper decoding of DTMF the decoded output then sent to PIC16F84A microcontroller. Microcontroller issues command to turn on/off devices connected as home and office appliance in accordance with program loaded in it. Then it executes program and provide output RB0,RB!,RB2,RB3.etc output.

Controlling of Devices:

LIMITATION:

1. The receiver must reside in a location where a signal with sufficient strength can be received from a cellular phone network.
2. Only devices with electrical controlling input ports will be possible targets for control.
3. The receiver must have a power source (12V) attached at all times.
4. Operation of the controlling unit is only possible through a cell phone with DTMF capabilities.
5. The controlling unit must be able to receive and decode DTMF.

FUTURE DIRECTION:

1. Possibility of confirming the devices initial condition (status) using short messaging system (SMS).
2. Though mobile in the control panel required to be charged, therefore charging system should be automated which meant a timer can be implemented so that mobile can be charged after a certain period and disconnected from the charger when not required.
3. The possibility to control the devices by voice message.

Submitted by H. M. G. SAROWER