What the BMP280 Actually Measures (and What It Doesn't)
Parts Used
If you’ve searched for this sensor on Amazon, you’ve almost certainly seen it described as a “temperature, humidity, and pressure” module — DST’s own listing said exactly that until this guide was written. It’s wrong. The BMP280 doesn’t measure humidity at all.
What Bosch’s own datasheet says
The official BMP280 datasheet titles the part outright: “BMP280 — Digital Pressure Sensor.” Not environmental sensor, not humidity sensor — pressure sensor. Its key parameters are pressure range, accuracy, temperature range, and interface speed. Its listed applications are GPS navigation refinement, indoor floor/elevation detection, weather forecasting, and watches — every one of them a pressure or temperature use case, with humidity absent from the entire document.
What it actually measures, verified against that datasheet:
| BMP280 | |
|---|---|
| Pressure range | 300–1100 hPa |
| Pressure accuracy | ±1 hPa (typ., 950–1050 hPa, 0–40°C) |
| Temperature range | −40°C to +85°C |
| Interface | I²C (up to 3.4 MHz) / SPI (up to 10 MHz) |
Where the confusion comes from
Bosch makes a genuinely different chip, the BME280, that adds a humidity sensor on top of the same pressure/temperature core — one letter apart in the part number, “P” for pressure vs “E” for environmental. The two chips ship on nearly identical-looking breakout boards, so sellers routinely reuse one listing template for both, and the humidity claim just gets copy-pasted onto BMP280 boards that physically cannot measure it. It’s an extremely common mix-up, not a DST-specific mistake — but that doesn’t make it accurate, which is why it’s fixed here.
The practical answer
If you only need temperature and pressure (altitude estimation, a weather station’s barometric trend, general environmental logging) — the BMP280 is the right, and cheaper, part for the job.
If you need humidity as well — you need a board built around the BME280 chip specifically, not this one. DST doesn’t currently stock a BME280 board; check the listing you’re looking at names the chip explicitly before buying if humidity matters for your build.