DTMF Based Door Opener System

DTMF Based Door Opener System

DTMF Cell Phone Based Door Opener System

Entry into a residence is still primarily limited to a manual process which involves inserting a key into a bolt and physically moving the locking mechanism. and its required physical involvement of person sometimes it’s too difficult for person with disability to open or close the door also it is not complete secure method if someone finds the key of lock then it is easy to open the door without owner’s permission. so we required the mechanism that develop remote devices and also reduces the human efforts and maintenance cost

So here we are introducing DTMF Cell Phone Based Door Opener System in which door is opened by using mobile phone where users entered the unique password to open/closed the door. To activate the mobile phone unit, the caller has to make a call which is connected to door. Then the user has to enter the password. As the caller enters a specific password, to open the doors If the password is wrongly entered four times in a row, from the interface – an error sound is generated. And thus, security is kept intact because these passwords are known and owned by selected persons only. DTMF frequencies are more practical and less expensive to implement than the other signalling method used by rotary telephones

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Block diagram:

This project includes DTMF {dual tone multi frequency} tones are composed of a series of low frequencies for each column of keys and a series of high frequencies for each row of keys. Each pressed key creates a signal that is equal to the sum of the column’s low frequency and the row’s high frequencies. When the signal is sent over the telephone line to the telephone company’s switching center, a DTMF decoder separates the signal back into the two frequencies and passes it along to the recipient’s phone. The DTMF decoder is responsible for doing this for all telephone numbers entered by all callers in its designated area every day.

When user wants to open the door he need to make a call on mobile which is connected to door. Once the key or password is entered by person it will check with key which is stored in 8085 microcontroller memory if the password is successful, then microcontroller initiates the mechanism to open the door and grant entrance. This automation introduces a form of secure, keyless entry into a residence along with the convenience of a fully responsive security system monitor.

Hardware specification

·        8051 Microcontroller

·        Power supply

·        DTMF decoder circuit

·        Cell phone

Software Specifications 

·       MC Programming Language: Embedded C

·       Keil version IDE

·       Proteus For Circuit &PCB Design