Security lock with DTMF polyphonic tone sensor

Home automation or known as smart home is a home which is equipped by a system for controlling and integrating electronic devices, such as lighting, home theater, CCTV (closed-circuit television), HVAC (heating, ventilation, and air conditioning), motion sensor, security lock sensor for gates or doors, and etc. Its main purpose is to provide the improved simplicity, energy efficiency, higher security, and better feelings at home for the user benefits. Smart phone could be integrated as part of ring tone sensor for security door lock automation system. Therefore in this work, locking automation system using smart phone polyphonic tone sensor has been designed and implemented. A simple unlocking mechanism is explained as follows. The DTMF (Dual Tone Multi Frequency) module which has simply been programmed with Arduino was used to receive the polyphonic tone signal which is embedded in smart phone system. Then that signal will be processed by Arduino Uno, so the solenoid will automatically unlock the door. But, after three seconds delay, it will lock again (protection system). However, this system still has some drawbacks, such as low security system, short working-range of sensitivity, and limited amount of password digits. Moreover, those limitations could be improved/solved in the near future.