bmp 180

bmp 180
arduino wiring
using-the-bmp085-api-v2
sensor driver

connection and explanations
Note in the diagram that the Arduino 5V rail is connected to the BMP sensor 3V3 input. The sensor board has a 3V3 LDO regulator capable of providing 100mA. The 5V rail from the Arduino should be connected to the VIN connector of the sensor which would utilise the regulator.