BMP280 Sensor

Product Description

Supports I2C and SPI interface.
Barometric Pressure absolute accuraccy: ±1hPa
Temperature accuraccy: ±1.0°C
Power consumption: ±2.7uA
Supply Voltage: 1.71V ~ 3.6V

Using barometric pressure, altitude can be calulated within ±1m accuraccy.

Links:
https://learn.adafruit.com/adafruit-bmp280-barometric-pressure-plus-temperature-sensor-breakout/overview
http://www.instructables.com/id/How-to-Use-the-Adafruit-BMP280-Sensor-Arduino-Tuto/
https://github.com/adafruit/Adafruit_BMP280_Library
Download the BMP280 datasheet

Sample Code