How to Use BMP280: Examples, Pinouts, and Specs

The BMP280 is a precision sensor from Bosch Sensortec that is designed for measuring barometric pressure and temperature. It is widely used in mobile applications, weather stations, indoor navigation, and fitness trackers due to its small form factor, low power consumption, and high accuracy.

• Weather monitoring
• Altitude tracking for drones and aircraft
• Indoor navigation and floor detection
• Environmental monitoring
• Smartphones and wearable devices

• Supply Voltage: 1.71 V to 3.6 V
• Interface: I2C (up to 3.4 MHz) and SPI (up to 10 MHz)
• Pressure Range: 300 hPa to 1100 hPa (equivalent to +9000m to -500m above/below sea level)
• Relative Accuracy: ±0.12 hPa, equivalent to ±1 m (at 25 °C)
• Absolute Accuracy: ±1 hPa (after soldering)
• Temperature Coefficient Offset: ±1.5 Pa/K, equivalent to ±12.6 cm/K at 1 °C temperature change
• Operating Temperature Range: -40 °C to +85 °C
• Temperature Accuracy: ±1.0 °C

1. Power Supply: Connect the VDD pin to a 1.71 V to 3.6 V power source and the GND pin to the ground.
2. Communication Interface: Choose between I2C and SPI for communication. For I2C, connect SDA and SCK to the corresponding I2C bus lines. For SPI, connect SDI, SDO, SCK, and CSB to your microcontroller's SPI bus.
3. Address Selection: For I2C, the BMP280 has one address pin (SDI). Connect it to GND for address 0x76 or VDD for 0x77.
4. I/O Voltage: Ensure that VDDIO is supplied with the correct logic level for your microcontroller's I/O.

• Use decoupling capacitors close to the power pins to filter out noise.
• Keep the sensor away from heat sources to avoid false temperature readings.
• For accurate pressure measurements, calibrate the sensor at a known altitude.
• Avoid physical stress and contamination during handling and mounting.

• Inaccurate Readings: Ensure that the sensor is not being affected by other heat sources and that it has been properly calibrated.
• Communication Errors: Check the wiring and ensure that the correct communication protocol and addresses are being used.

• Verify the power supply voltage and connections.
• Check the I2C/SPI bus with an oscilloscope to ensure signals are being transmitted correctly.
• Use pull-up resistors on the I2C lines if necessary.
• Ensure that the microcontroller's logic level matches the VDDIO voltage.

Q: Can the BMP280 measure altitude? A: Yes, by converting the barometric pressure readings to altitude using a standard formula.

Q: What is the difference between the BMP280 and the BME280? A: The BME280 is similar to the BMP280 but also includes a humidity sensor.

Q: How can I reduce power consumption when using the BMP280? A: Utilize the sensor's built-in power-saving modes and adjust the sampling rate according to your application's needs.

Below is an example of how to interface the BMP280 with an Arduino UNO using the I2C communication protocol.

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP280.h>

Adafruit_BMP280 bmp; // I2C Interface

void setup() {
  Serial.begin(9600);
  if (!bmp.begin(0x76)) {   // Change to 0x77 depending on your wiring
    Serial.println(F("Could not find a valid BMP280 sensor, check wiring!"));
    while (1);
  }
  
  // Configure the sensor
  bmp.setSampling(Adafruit_BMP280::MODE_NORMAL,     /* Operating Mode. */
                  Adafruit_BMP280::SAMPLING_X2,     /* Temp. oversampling */
                  Adafruit_BMP280::SAMPLING_X16,    /* Pressure oversampling */
                  Adafruit_BMP280::FILTER_X16,      /* Filtering. */
                  Adafruit_BMP280::STANDBY_MS_500); /* Standby time. */
}

void loop() {
  Serial.print(F("Temperature = "));
  Serial.print(bmp.readTemperature());
  Serial.println(" *C");

  Serial.print(F("Pressure = "));
  Serial.print(bmp.readPressure() / 100.0F);
  Serial.println(" hPa");

  Serial.print(F("Approx altitude = "));
  Serial.print(bmp.readAltitude(1013.25)); // Standard atmospheric pressure
  Serial.println(" m");

  delay(2000);
}

Remember to install the Adafruit BMP280 library before uploading this code to your Arduino UNO. The library provides a simple interface for reading temperature, pressure, and calculating altitude. Adjust the bmp.begin() address and the sampling settings as needed for your specific application.