BMP280-5V Temperature and Barometric Pressure Sensor Module

The BMP280 IC itself requires a supply voltage (VDD) between 1.71V and 3.6V. This module includes an onboard 3.3V low-dropout (LDO) regulator, which safely steps down the 5V input power to the appropriate level for the sensor. You must power the module with 5V; do not apply 5V directly to the sensor's VCC pin.

The interface is selected via the module's SDO pin. For I2C mode, leave the SDO pin unconnected (or pull it high) and use the SCL and SDA pins. For SPI mode, connect the SDO pin as the SPI MISO line and use the standard SPI pins (SCK, MOSI, CS). The default factory configuration is typically I2C with address 0x76.

Altitude calculation accuracy depends on pressure measurement precision and local SEA-level pressure reference. With a typical relative pressure accuracy of ±0.12 hPa, the BMP280 can achieve altitude resolution better than ±1 meter under stable atmospheric conditions. Accuracy is highest when used for relative altitude changes rather than absolute altitude from SEA level.

Yes, the BMP280's high precision and stability make it suitable for detecting subtle barometric pressure trends, which are key for short-term weather forecasting. By logging pressure changes over time (e.g., a falling pressure trend often indicates approaching inclement weather), the sensor can provide valuable data for personal weather stations.

The Bosch BMP280 is factory calibrated, and individual calibration coefficients are stored in the chip's non-volatile memory. Your microcontroller must read these compensation parameters (provided in the datasheet's algorithm) and apply them to the raw temperature and pressure data registers to achieve the specified accuracy. Most open-source libraries (e.g., Adafruit_BMP280) handle this compensation automatically.