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title: BME280 (Adafruit STEMMA QT) description: Bosch's three-in-one environmental sensor: temperature, humidity, and barometric pressure. I²C or SPI; the STEMMA QT module is plug-and-play with...

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sensors / bme280.md

BME280 (Adafruit STEMMA QT)

Bosch's three-in-one environmental sensor: temperature, humidity, and barometric pressure. I²C or SPI; the STEMMA QT module is plug-and-play with Qwiic/Grove-style cables.

In stock Bosch / Adafruit CC-BY-SA-3.0 2 files · 1.6 MB

Specs

Spec	Value
Temp	-40 to 85 °C, ±1 °C
Humidity	0–100 %RH, ±3 %
Pressure	300–1100 hPa, ±1 hPa
Bus	I²C or SPI
I²C address	0x77 (or 0x76 if SDO grounded)
Voltage	3.3 V (Adafruit board has LDO + LS, accepts 5 V)

Wiring (I²C, Arduino Uno)

Adafruit pin	Arduino
Vin	5 V
GND	GND
SDA	A4
SCL	A5

STEMMA QT: just plug the cable into another Qwiic/STEMMA QT board — no soldering.

Code

#include <Adafruit_BME280.h>
Adafruit_BME280 bme;
void setup() {
  Serial.begin(115200);
  if (!bme.begin(0x77)) { Serial.println("No BME280"); while (1); }
}
void loop() {
  Serial.printf("%.1f C  %.1f %%RH  %.1f hPa  %.0f m\n",
    bme.readTemperature(), bme.readHumidity(),
    bme.readPressure() / 100.0, bme.readAltitude(1013.25));
  delay(2000);
}

Schematic

Adafruit's BME280 breakout is open-hardware (CC BY-SA-3.0). Eagle files + schematic PDF on GitHub: adafruit/Adafruit-BME280-PCB.

Last updated: 2026-05-13 · Source on GitHub