GY-BMP280 Digital Barometric Pressure and Altitude Sensor

The BMP280 measures barometric pressure precisely enough to double as an altimeter: since air pressure drops predictably with altitude, a sensor accurate to about 1 hPa translates to roughly 1 metre of altitude resolution, which is what makes this chip a staple in flight controllers and weather stations alike. Temperature is measured alongside pressure on the same die, both compensated in hardware before the reading reaches the microcontroller.

It offers both I2C and SPI interfaces on the same board - I2C for simple two-wire wiring when only one or two sensors share the bus, SPI when several sensors need to coexist without I2C address conflicts. Power draw is low enough for battery-powered projects, and it directly replaces the older BMP180/BMP183 in most designs.

Common uses are DIY weather stations, altitude-hold logic in flight controllers and drones, and indoor/outdoor navigation projects that use pressure changes to detect floor changes in a building.