METHODOLOGY

            A block diagram can be produce after done with a literature review on the principle operation, a technology and program involve, sensors involve and other. The gas leakage detector sensor requires more than one sensor such as MG5 gas sensor, LDR sensor, IR distance sensor and line sensor. Two small DC motor are needed to move the device from one location to another location. A gas leakage detector sensor also completed with alarm and buzzer system.

Block diagram

Figure 1.3: Block diagram for gas leakage detector system

Referring to the figure above, a MQ5 gas sensor is used to detect any presence of liquefied petroleum (LPG). When it detects any leakage of liquefied petroleum gas (LPG), a data will be send to the microcontroller which is A Tmega 328. The microcontroller will process the received data and automatically turn the siren or alarm on. A line sensor is optically detecting the specific line placed on the floor and move only on the specific line. A data received from the line sensor will be send to the microcontroller and run the DC motor (L293D). Furthermore, a light dependent resistor sensor or known as LDR sensor is used to detect the light surrounding the device. A data from this sensor will be read by the microcontroller and turn the lamp on. This will happen when the device moves into a dark places where no light on that area but it will automatically turn the lamp off when there is a light detect by the LDR sensor. The function of infrared distance sensor (IR distance sensor) is to detect any presence object against it. When it faces an external object or humans, it will send the data to be process by the microcontroller and turn on the buzzer to notify the user and organic life against it.

Table 1.4: Input, process and output of the block diagram

INPUT

1. .      Push button start and stop – Use to start and stop all the operation of gas leakage detector system.
2. .      MQ5 gas sensor – An electronic device use to detect any presence of propane or butane gas.
3. .      Line sensor – Is a sensor which only detect a black line on the floor.
4. .      LDR sensor – This sensor will be used to detect the light or dark area.
5.     IR distance sensor – It can detect any existing obstacle against it

         

          PROCESS

1.      ATmega 328 – Can store all the data written by the user and control all the system for gas   leakage detector system.

OUTPUT

1.      Alarm – Able to produce a high volume of sound and use to notify the user if any gas detected.

2.      DC motor – A low voltage motor use to move the device.

3.      Lamp or LED – Provide a indicator light when operates in a dark area.

4.      Buzzer – Notify the user if any obstacle block the device.