Abstract:

The project is designed on the DTMF decoding. Our modern telephone and even our mobile phone uses DTMF coding for number dialing. These DTMF codes can be decoded and utilised for useful purposes. The circuit utilizes IC8870 for DTMF decoding. Microcontroller 89C51 reads these codes and takes necessary action. Door latch can be opened by entering the correct password; we can also connect security sensors of our choice. In case of any breach of security, the device will dial out the pre-stored number and deliver an emergency message.