BMP280 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_BMP280.h>

const int SDA_PIN = 8, SCL_PIN = 9;     // use your board's I2C pins
const float SEA_LEVEL_HPA = 1013.25;    // replace with today's local value
Adafruit_BMP280 bmp(&Wire);

void setup() {
  Serial.begin(115200);
  Wire.begin(SDA_PIN, SCL_PIN);
  if (!bmp.begin(0x76) && !bmp.begin(0x77)) {
    Serial.println("No sensor at 0x76 or 0x77");
    while (true) delay(1000);
  }
  Serial.printf("Chip ID 0x%02X\n", bmp.sensorID());
}

void loop() {
  Serial.printf("%.1f C  %.1f hPa  %.1f m\n", bmp.readTemperature(),
                bmp.readPressure() / 100.0, bmp.readAltitude(SEA_LEVEL_HPA));
  delay(2000);
}

Needs the Adafruit BMP280 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

Read the value in your sketch and pass it to a label, or send it over MQTT and show it with an MQTT value in the editor.

Boards with a ready connector

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

Good to know

• No humidity output. For that, use a BME280.
• Sellers mix up BMP280 and BME280 boards.
• Altitude needs today's sea-level pressure.
• Heat from nearby parts raises the temperature reading.

What it is good for

• Weather trend displays
• Relative height changes
• Pressure logging

FAQ

Sources

• https://learn.adafruit.com/adafruit-bmp280-barometric-pressure-plus-temperature-sensor-breakout?view=all

Related parts

• BME280
• BME680