This is a BMP280/BME280 temperature/pressure/humidity sensor library for Arduino.
- Measurements:
- BMP280: Temperature / pressure / approximate altitude
- BME280: Temperature / pressure / approximate altitude / humidity
- Three operation modes:
- Normal mode: Continues conversion
- Forced mode: One-time conversion
- Standby mode: Low-power, no conversion
- Sampling configuration
- Chip detect / read chip ID
- I2C interface only
- Small flash/RAM footprint
- Operating voltage: 1.71V .. 3.6V max
- Low current:
- 1.8 uA @ 1 Hz humidity and temperature
- 2.8 uA @ 1 Hz pressure and temperature
- 3.6 uA @ 1 Hz humidity, pressure and temperature
- 0.1 uA in sleep mode
- Operating range: -40...+85 °C, 0...100 % rel. humidity, 300...1100 hPa
- I2C bus interface: max 3.4 MHz
- No additional electronic components needed
Connection Arduino board - BMX280 sensor
| Pins board - BMX280 | VCC | GND | SDA | SCL |
|---|---|---|---|---|
| Arduino UNO (ATMega328 boards) | 5V | GND | A4 | A5 |
| Arduino Mega2560 | 5V | GND | D20 | D21 |
| Arduino Leonardo | 5V | GND | D2 | D3 |
| Arduino DUE (ATSAM3X8E) | 3V3 | GND | 20 | 21 |
| ESP8266 | 3V3 | GND | GPIO4 (D2) | GPIO5 (D1) |
| ESP32 | 3V3 | GND | GPIO21 | GPIO22 |
Other unlisted MCU's may work, but are not tested.
Examples | Erriez BMP280/BME280 sensor:
#include <Wire.h>
#include <ErriezBMX280.h>
// Adjust sea level for altitude calculation
#define SEA_LEVEL_PRESSURE_HPA 1026.25
// Create BMX280 object I2C address 0x76 or 0x77
// This uses the default Wire object
ErriezBMX280 bmx280 = ErriezBMX280(0x76);
// To use a different I2C bus (e.g., Wire1 on ESP32 or Due):
// 1. Make sure your board supports Wire1.
// 2. Include Wire1 if necessary (usually included with Wire.h).
// 3. Initialize Wire1 in setup(): Wire1.begin(); Wire1.setClock(400000);
// 4. Create the object passing the Wire1 instance:
// ErriezBMX280 bmx280_on_wire1 = ErriezBMX280(0x76, &Wire1);
void setup()
{
// Initialize serial
delay(500);
Serial.begin(115200);
while (!Serial) {
;
}
Serial.println(F("\nErriez BMP280/BMX280 example"));
// Initialize the default I2C bus
Wire.begin();
Wire.setClock(400000);
// If using Wire1, initialize it here:
// Wire1.begin(); // Add SDA/SCL pins for ESP32 if needed
// Wire1.setClock(400000);
// Initialize sensor (use the correct object, e.g., bmx280 or bmx280_on_wire1)
while (!bmx280.begin()) {
Serial.println(F("Error: Could not detect sensor"));
delay(3000);
}
// Print sensor type
Serial.print(F("\nSensor type: "));
switch (bmx280.getChipID()) {
case CHIP_ID_BMP280:
Serial.println(F("BMP280\n"));
break;
case CHIP_ID_BME280:
Serial.println(F("BME280\n"));
break;
default:
Serial.println(F("Unknown\n"));
break;
}
}
void loop()
{
// Read sensor data using the correct object (e.g., bmx280 or bmx280_on_wire1)
float temperature = bmx280.readTemperature();
float pressure = bmx280.readPressure();
float altitude = bmx280.readAltitude(SEA_LEVEL_PRESSURE_HPA);
Serial.print(F("Temperature: ")); Serial.print(temperature); Serial.println(F(" *C"));
Serial.print(F("Pressure: ")); Serial.print(pressure / 100.0); Serial.println(F(" hPa"));
Serial.print(F("Altitude: ")); Serial.print(altitude); Serial.println(F(" m"));
// Read humidity if it's a BME280
if (bmx280.getChipID() == CHIP_ID_BME280) {
float humidity = bmx280.readHumidity();
Serial.print(F("Humidity: ")); Serial.print(humidity); Serial.println(F(" %RH"));
}
Serial.println();
delay(2000);
}Output
Erriez BMP280/BMX280 example
Sensor type: BME280
Temperature: 28.50 C
Humidity: 45.13 %
Pressure: 1024.88 hPa
Altitude: 11.27 m
Temperature: 28.55 C
Humidity: 45.21 %
Pressure: 1024.89 hPa
Altitude: 11.21 m
...The sensor sampling and mode can be configured with function setSampling(). Recommended modes of
operation according to the datasheet chapter "Recommended modes of operation":
// Set sampling
//
// Weather
// - forced mode, 1 sample / minute
// - pressure ×1, temperature ×1, humidity ×1
// - filter off
//
// Humidity sensing
// - forced mode, 1 sample / second
// - pressure ×0, temperature ×1, humidity ×1
// - filter off
//
// Indoor navigation
// - normal mode, t standby = 0.5 ms
// - pressure ×16, temperature ×2, humidity ×1
// - filter coefficient 16
//
// Gaming
// - forced mode, t standby = 0.5 ms
// - pressure ×1, temperature ×1, humidity ×1
// - filter off
bmx280.setSampling(BMX280_MODE_NORMAL, // SLEEP, FORCED, NORMAL
BMX280_SAMPLING_X16, // Temp: NONE, X1, X2, X4, X8, X16
BMX280_SAMPLING_X16, // Press: NONE, X1, X2, X4, X8, X16
BMX280_SAMPLING_X16, // Hum: NONE, X1, X2, X4, X8, X16 (BME280)
BMX280_FILTER_X16, // OFF, X2, X4, X8, X16
BMX280_STANDBY_MS_500);// 0_5, 10, 20, 62_5, 125, 250, 500, 1000- Built-in
Wire.h
Please refer to the Wiki page.