Fire sensor is the one type of transducer which is used to sense the flame. If any fire happens in the house the flame sensor will detect that fire and generate the voltage signal which is given to comparator. Gas sensor is also one type transducer which is used to sense the gas leakage in the house. If any gas leakage in the house it will sense that leakage and send the voltage signal to comparator.
Infrared transmitter and receiver are fixed in the entrance door. Initially the infrared transmitter transmits the rays to the receiver. If any one crosses the rays it sends the signal to microcontroller through comparator. The comparator is used to compare the acquired signal from the sensor with reference level. If any one transducer is activated due to that corresponding reason the comparator gives the error voltage to microcontroller.
Here the microcontroller is the flash type reprogrammable microcontroller in which we have already programmed with desired phone number. The mobile phone is interfaced with microcontroller through data cable and RS 232. Data cable is the special type of cable available with mobile phone. RS 232 converts TTL logic to RS 232 logic.
The microcontroller received the signal from the comparator and automatically dialed to authority person as per the number is stored in the microcontroller and also turns ON the voice synthesizer. In the voice synthesizer we have already stored with corresponding information in the voice format.