BME680

In this article we will connect a BME680 sensor to a Micro:bit

BME680 is an integrated environmental sensor developed specifically for mobile applications and wearables where size and low power consumption are key requirements. Expanding Bosch Sensortec’s existing family of environmental sensors, the BME680 integrates for the first time high-linearity and high-accuracy gas, pressure, humidity and temperature sensors. The gas sensor within the BME680 can detect a broad range of gases to measure air quality for personal well being.

Gases that can be detected by the BME680 include Volatile Organic Compounds (VOC) from paints (such as formaldehyde), lacquers, paint strippers, cleaning supplies, furnishings, office equipment, glues, adhesives and alcohol.

 

Parts List

Schematic

 

 

Code

You will need to import the adafruit sensor and bme680 libraries – you can add these using the library manager

My particular sensor used address 0x76, the default address in the library is 0x77 so you may have to change this line from if (!bme.begin(0x76)) to if (!bme.begin())

 

[codesyntax lang=”cpp”]

#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include "Adafruit_BME680.h"


#define SEALEVELPRESSURE_HPA (1013.25)

Adafruit_BME680 bme; // I2C

void setup() {
  Serial.begin(9600);
  while (!Serial);
  Serial.println(F("BME680 test"));

  if (!bme.begin(0x76)) 
  {
    Serial.println("Could not find a valid BME680 sensor, check wiring!");
    while (1);
  }

  // Set up oversampling and filter initialization
  bme.setTemperatureOversampling(BME680_OS_8X);
  bme.setHumidityOversampling(BME680_OS_2X);
  bme.setPressureOversampling(BME680_OS_4X);
  bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
  bme.setGasHeater(320, 150); // 320*C for 150 ms
}

void loop() 
{
  if (! bme.performReading()) 
  {
    Serial.println("Failed to perform reading :(");
    return;
  }
  Serial.print("Temperature = ");
  Serial.print(bme.temperature);
  Serial.println(" *C");

  Serial.print("Pressure = ");
  Serial.print(bme.pressure / 100.0);
  Serial.println(" hPa");

  Serial.print("Humidity = ");
  Serial.print(bme.humidity);
  Serial.println(" %");

  Serial.print("Gas = ");
  Serial.print(bme.gas_resistance / 1000.0);
  Serial.println(" KOhms");

  Serial.print("Approx. Altitude = ");
  Serial.print(bme.readAltitude(SEALEVELPRESSURE_HPA));
  Serial.println(" m");

  Serial.println();
  delay(2000);
}

[/codesyntax]

 

Output

Open the serial monitor and you will see something like this

Start
Actual temp BME680 test
Temperature = 20.19 *C
Pressure = 974.45 hPa
Humidity = 40.07 %
Gas = 0.00 KOhms
Approx. Altitude = 328.16 m

Temperature = 20.54 *C
Pressure = 974.43 hPa
Humidity = 40.03 %
Gas = 100.36 KOhms
Approx. Altitude = 328.16 m

Temperature = 20.74 *C
Pressure = 974.41 hPa
Humidity = 39.91 %
Gas = 109.98 KOhms
Approx. Altitude = 328.51 m