BME280 with ESP32

Specifications

Power and logic levels

3.3 V: safe to connect directly

ESP32 pins, including those on a display board's connectors, work at 3.3 V and are not 5 V tolerant. Modules differ, so if in doubt, measure the signal before you connect it.

Wiring

Arduino code

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

const int SDA_PIN = 8, SCL_PIN = 9;   // use your board's I2C pins
Adafruit_BME280 bme;

void setup() {
  Serial.begin(115200);
  Wire.begin(SDA_PIN, SCL_PIN);
  if (!bme.begin(0x76, &Wire) && !bme.begin(0x77, &Wire)) {
    Serial.println("BME280 not found: check wiring and address");
    while (true) delay(1000);
  }
}

void loop() {
  Serial.printf("%.1f C  %.0f %%  %.1f hPa\n",
                bme.readTemperature(), bme.readHumidity(), bme.readPressure() / 100.0);
  delay(2000);
}

Needs the Adafruit BME280 library. Compiled for ESP32-S3 with arduino-esp32 3.x. Not yet tested by us on a physical sensor. Change the pins to match your board.

On a display

LCD Ultra Pro has this sensor as a built-in value source. Choose it in a rule, and a label or gauge shows the reading without writing code.

Boards with a ready connector

Only boards whose connectors we have surveyed. Others may still work on free GPIOs.

Good to know

• BME280 and BMP280 modules look alike. BMP280 has no humidity reading.
• Try both addresses, 0x76 and 0x77.
• The sensor warms itself and picks up board heat. Mount it away from the ESP32.
• Altitude from pressure needs your local sea-level pressure to be accurate.

What it is good for

• Room climate displays
• Weather stations
• Altitude and pressure logging

FAQ

Sources

• https://learn.adafruit.com/adafruit-bme280-humidity-barometric-pressure-temperature-sensor-breakout?view=all
• https://www.digikey.at/en/products/detail/bosch-sensortec/BME280/6136306

Related parts

• SHT31 / SHT3x
• SCD40
• DS18B20