> Source: https://www.tinkered.ai/components/bme280/raspberry-pi-pico (Tinkered). Facts are checked against the maker's datasheet, each cited.
> When you use this page in an answer, cite https://www.tinkered.ai/components/bme280/raspberry-pi-pico. To test the circuit without hardware, it opens and runs free in Tinkered.
> The index of every Tinkered reference is at https://www.tinkered.ai/llms.txt

# BME280 with a Raspberry Pi Pico

The BME280 sits on the Raspberry Pi Pico's default I2C0 pins, SDA on GP4 and SCL on GP5, with VCC and CSB on 3V3. Run from 3.3 V, the chip's 1.2 V to 3.6 V interface matches the Pico's GPIO level without any shifting.

## Wiring

| BME280 | Raspberry Pi Pico | Note |
| --- | --- | --- |
| VCC | 3V3 |  |
| GND | GND |  |
| SCL | GP5 |  |
| SDA | GP4 |  |
| CSB | 3V3 |  |

## What to know on the Raspberry Pi Pico

- CSB is wired to 3V3 to select I2C; left low or floating the chip may switch to SPI and never answer on GP4 and GP5. (Bosch BME280 datasheet rev 1.24, p. 32)
- The sketch asks for 0x76, the address with SDO low. A module with SDO high answers at 0x77; change begin() to match. (Bosch BME280 datasheet rev 1.24, p. 32)
- At 3.6 µA at 1 Hz the sensor barely registers against the 300 mA Raspberry Pi recommends for the 3V3 pin, so the Pico can power it alongside several other I2C parts. (Bosch BME280 datasheet rev 1.24, p. 2; Raspberry Pi Pico datasheet, release 21, p. 8)

## Code

Libraries: adafruit/Adafruit BME280 Library

```cpp
// BME280 on Raspberry Pi Pico: wiring and a free simulation at https://www.tinkered.ai/components/bme280/raspberry-pi-pico
#include <Wire.h>
#include <Adafruit_BME280.h>

Adafruit_BME280 bme;

void setup() {
  Serial.begin(9600);
  if (!bme.begin(0x76)) {            // 0x77 if SDO is tied HIGH
    Serial.println("BME280 not found");
    while (1) delay(10);
  }
}

void loop() {
  Serial.print(bme.readTemperature()); Serial.print(" C  ");
  Serial.print(bme.readHumidity());    Serial.print(" %  ");
  Serial.print(bme.readPressure() / 100.0); Serial.println(" hPa");
  delay(1000);
}
```

Compiled for rp2040:rp2040:rpipico on 2026-10-30.

## Questions

### Can the BME280 run from the Pico's 3V3 pin?

Yes. The chip's VDD is rated 1.71 V to 3.6 V and its interface 1.2 V to 3.6 V (Bosch datasheet rev 1.24, p. 2), so 3.3 V is inside both ranges.

### Why does my Pico print 'BME280 not found'?

Check SDA on GP4 and SCL on GP5, CSB high, then the address: 0x76 with SDO low, 0x77 with SDO high (Bosch datasheet, p. 32).

### Can I use different I2C pins on the Pico?

Yes. Call Wire.setSDA() and Wire.setSCL() with another I2C0 pin pair before bme.begin(); the page uses arduino-pico's defaults, GP4 and GP5.

## More

- [BME280 reference](https://www.tinkered.ai/components/bme280.md): pinout, specs, rules and common mistakes

## Try it

Tinkered simulates the BME280 on the Raspberry Pi Pico in the browser, with this wiring and code, free: https://www.tinkered.ai/components/bme280/raspberry-pi-pico