18-06-2011, 04:48 PM
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DTMF BASED DEVICE CONTROLLING SYSTEM
ABSTRACT
In this competitive world human cannot spare his time to perform his daily activities manually without any fail. The most important thing he forgets to switch off the room lights wherever not required. With this, even the power will be wasted up to some extent. This project gives the best solution for electrical power wastage. Also the manual operation is completely eliminated. The industrial appliances can be switched on/off using DTMF TECHNOLOGY.
The main function of the system is to control any electrical devices through mobile phone. In this concept two mobile phones with different service numbers are used, the control phone at receiving end, where the appliances are controlled is interfaced with microcontroller unit which controls the devices through relays.
To achieve this, the output of the mobile is amplified and fed to DTMF (Duel Tone Multi Frequency) decoder chip, which generates binary code according to the received information from the other mobile phone. After establishing a communication page link between the two mobiles by dialing the home mobile number, the corresponding keys of calling phone must be activated to generate different DTMF signals. Based on this signals, the DTMF decoder generates different binary codes through four outputs, and this data is Fed to the microcontroller. Now the program is prepared for the microcontroller to energize or de-energize the corresponding relay based on the code produced by the DTMF decoder chip.
Software:
1) Keil C
2) ORCAD/Express PCB
Hardware:
1) Micro controller.
2) DTMF
3) LCD module.
4) Power supply.
