urrently BMP 180 atmospheric pressure sensor is available in two modules. First one consists of four pins and second one consists of five pins means with 3.3V additional pin which is not available in four pins module. But the functions of both are almost same. The pin configuration of this BMP 180 atmospheric pressure sensor is shown in figure 2
Figure 2 Pin Configuration of BMP 180 Atmospheric Pressure Sensor
Its pin configuration is shown in table,
|No. of Pins||Configuration|
|VCC||This is power pin and is connected to 3.3V to 5V dc source.|
|SDA||This is serial data pin and is used for serial communication.|
|SCL||This is serial clock pin and is used for clock pulse.|
|3.3V||This is also power pin and is used when 5V dc is not available.|
|GND||This ground pin and connected to source ground.|
Working Principle of BMP 180 Atmospheric Pressure Sensor
The working principle of this atmospheric pressure sensor is very simple it works on the base of air weight. Because our surrounding air has a certain weight and this weight has specific pressure.SO, this pressure is sensed by BMP 180 atmospheric pressure sensor. Which is actually consists of four basic components, fist one is piezo resistive sensor, second one is analogue to digital converter, third one is control unit with E2PROM and fourth one is 12C serial interface. When the air weight or pressure is changed then the resistance of piezo resistive sensor is changed. Because this change value is an analogue value therefore this value is converted to digital value through analogue to digital converter. Then this value is control through control unit and eventually it is sent towards any type of controller with the help of 12C serial interface.
How to Interface BMP 180 Atmospheric Pressure Sensor with Arduino Board
For measuring atmospheric pressure with the help of this BMP 180 atmospheric pressure sensor a controller is must is required for interfacing purpose. Here we shell tell the user how interface this sensor with Arduino board. For interfacing with Arduino board connections are made according to figure 3
Figure 3 Interfacing Connection of BMP 180 Atmospheric Pressure sensor with Arduino Board
According to figure 3, BMP 180 atmospheric pressure sensor is powered up with Arduino board and for this purpose GND and VCC pins are used. Similarly, for data collection A4 and A5 pins of Arduino board are used. After making connection , a logic program is made up by using Arduino library and it is up load in Arduino board with the help of Arduino IDE software.