GSM or cell phone controlled home appliances

SPECIFICATIONS

Title of the project                  :           GSM/cell phone controlled home appliances

                                                                       

Domain                                    :           Embedded Systems Design

Software                                  :           Assembler, Proload

Microcontroller                      :           89S52 CISC Micro Controller

Power Supply                          :           +5V, 500mA Regulated Power Supply

Display                                     :           a) LCD,  HD44780 16-character, 2-line (16X2)

                                                            b) LED              5mm

Crystal                                     :           11.0592MHz

Sensors                                    :           DTMF decoder

Audio indiacation                    :           Buzzer

Applications                            :           Homes, offices, shops etc

ABSTRACT

We designed and constructed a cell phone controlled house automation system. The system allows users to send commands from their cell phones to control both a LIGHT and cooler.

Commands are sent via a cell phone’s numeric code dialing capability. The system is equipped with DTMF decoder and relay driver for controlling any appliance. The design is modular hence we can expand the system for more switches. The main advantage of the circuit is its vast range it can control any device from anywhere in the world. The reliability of the circuit is greatly enhanced due to availability of low cost cell phones and interfacing connectors.

Our design met all the intended objectives however; improvements can still be made in the algorithm to make it more users friendly and reliable.

Overall, the final price of implementation was kept low due to simplicity of the circuit. All the components are locally available.  However, if this product were to be produced and sold, further cuts would be needed to make the end price competitive. 

This project uses regulated 5v, 500mA power supply. 7805, a three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of secondary of 230/12v step down transformer.

BLOCK DIAGRAM