The fig shows block diagram of SMS based fire detection system.
It consists of following blocks.
Power supply is used to provide voltage to the Microcontroller, LCD, sensors, ADC, buzzer etc.
Sensor are basically use to convert physical quantity (eg. Temp, smoke etc) in electrical form (voltage, current etc.)
there are different sensors available for various physical quantity.
For FIRE detection we use Smoke sensor MQ2, Temp. Sensor LM35 & fire sensor.
If smoke is detected, then smoke sensor (MQ2: smoke to analog voltage) give signal to the ADC. The temp sensor LM35 (temp to analog voltage) sense the temp if it exceeds the max temp level then it sends the signal to the ADC. If fire is detected, then fire sensor gives signal to the microcontroller.
ADC is used to convert analog signal into digital form. In our project we use ADC0808. ADC receive signal from temp sensor & smoke sensor & convert it into digital form & this digital signal sends to the microcontroller.
Microcontroller is the main control unit of project. Once microcontroller gets signal from sensors (via ADC), if fire is detected then it will immediately turn on the buzzer & send the signal to the GSM modem.
In project we used GSM modem for message sending.
When microcontroller detects fire then it sends information to the GSM modem, then GSM modem sends this information via SMS. GSM modem is used to send the message to the fire stations well as to the responsible person.
Display is used to display the system status.
Buzzer is used for notification regarding fire detection.
If fire is detecting, then microcontroller sends signal to the buzzer.