BME680簡介

BME680是一個四合一數位環境檢測感測器，可以測量所處周圍環境的溫度、溼度、氣壓、有機揮發性化合物(VOC)。其內部的金屬氧化物敏感元件用於測量空氣中的VOCs，不同VOCs濃度下金屬氧化物表面的電導率不一樣從而輸出不同的電阻值。這個感測器能給到一個關於周圍空氣中VOCs/汙染物之和的定性概念，而不是特定的氣體分子。

敏感元件	測量範圍	精度
溫度	-40 to 85 ºC	+/- 1.0 ºC
溼度	0 to 100 %	+/- 3 %
氣壓	300 to 1100 hPa	+/- 1 hPa

介面說明

VCC 供電正極3.3-5V
GND 供電負極
SCL SPI/IIC模式時鐘訊號輸入
SDA SPI模式的MOSI資料訊號的輸入，IIC模式的資料訊號的輸入和輸出
SDO SPI模式的MISO資料訊號的輸出，IIC模式時為IIC器件地址設定引腳，接GND時器件地址為1110110(0x76)，接VCC時器件地址為1110111(0x77)
CS SPI/IIC模式的選擇引腳，當接VCC時為IIC模式，當接GND時為SPI模式

BME680與Arduino UNO接線與程式

BME680	SPI接線方式	IIC接線方式
SCL	D13	A5
SDA	D11	A4
SDO	D12	/
CS	D10	/

IIC接線方式

Arduino IDE庫管理器安裝 Adafruit_BME680 library

Arduino IDE庫管理器安裝Adafruit Unified Sensor

開啟範例程式碼

/***************************************************************************
  This is a library for the BME680 gas, humidity, temperature & pressure sensor

  Designed specifically to work with the Adafruit BME680 Breakout
  ----> http://www.adafruit.com/products/3660

  These sensors use I2C or SPI to communicate, 2 or 4 pins are required
  to interface.

  Adafruit invests time and resources providing this open source code,
  please support Adafruit and open-source hardware by purchasing products
  from Adafruit!

  Written by Limor Fried & Kevin Townsend for Adafruit Industries.
  BSD license, all text above must be included in any redistribution
 ***************************************************************************/

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

#define BME_SCK 13
#define BME_MISO 12
#define BME_MOSI 11
#define BME_CS 10

#define SEALEVELPRESSURE_HPA (1013.25)

Adafruit_BME680 bme; // I2C
//Adafruit_BME680 bme(BME_CS); // hardware SPI
//Adafruit_BME680 bme(BME_CS, BME_MOSI, BME_MISO, BME_SCK);

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

  if (!bme.begin()) {
    Serial.println(F("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() {
  // Tell BME680 to begin measurement.
  unsigned long endTime = bme.beginReading();
  if (endTime == 0) {
    Serial.println(F("Failed to begin reading :("));
    return;
  }
  Serial.print(F("Reading started at "));
  Serial.print(millis());
  Serial.print(F(" and will finish at "));
  Serial.println(endTime);

  Serial.println(F("You can do other work during BME680 measurement."));
  delay(50); // This represents parallel work.
  // There's no need to delay() until millis() >= endTime: bme.endReading()
  // takes care of that. It's okay for parallel work to take longer than
  // BME680's measurement time.

  // Obtain measurement results from BME680. Note that this operation isn't
  // instantaneous even if milli() >= endTime due to I2C/SPI latency.
  if (!bme.endReading()) {
    Serial.println(F("Failed to complete reading :("));
    return;
  }
  Serial.print(F("Reading completed at "));
  Serial.println(millis());

  Serial.print(F("Temperature = "));
  Serial.print(bme.temperature);
  Serial.println(F(" *C"));

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

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

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

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

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

開啟串列埠監視器顯示出感測器測量的資料

總結

首次使用感測器器時建議使其工作48小時後其測量的資料相對穩定準確，建議使感測器工作半小時後讀取到的氣敏電阻值相對準確。通過本實驗能快速直觀的使用感測器獲取所處環境的引數。