物联网(IoT)教程

压力传感器BMP180和Arduino设备进行温度，压力和高度测量

这是一个使用压力传感器BMP180和Arduino设备进行温度，压力和高度测量的物联网(物联网)项目。

在这个项目中，我们将建立一个温度，压力和高度测量系统。使用气压传感器模型BM 180来检测温度，大气压力和海拔高度，Arduino设备和16 X 4字符LCD显示计算的温度，压力和海拔高度。

硬件要求

Arduino UNO主板
用于Arduino设备的USB电缆连接器
压力传感器BMP180
16 X 4字符LCD显示屏
项目主板
跳线(公线对公线，公线对母线)

软件要求

Arduino软件IDE

压力传感器BMP180的工作原理

压力传感器BMP180由压阻式传感器，模拟和数字转换器，带E2PROM的控制单元和串行I2C接口组成。它提供温度，大气压力和海拔高度的贡献值。传感器设备的微控制器发送启动序列以测量温度，压力和高度。温度，压力和高度的值通过16X4字符LCD读取。

计算的温度，压力和高度分别以℃(摄氏度)，hPa(hector Pascal)和英尺为单位测量。在这种情况下，测量温度，大气压力和高度的速率是每秒一次。

高度和压力彼此成反比。当海拔升高时，压力下降，当海拔降低时，导致大气压力增加。

压力传感器工作原理

使用压力传感器BMP180，Arduino和字符LCD编写Arduino程序来测量温度，压力和高度。

#include <LiquidCrystal.h>  
LiquidCrystal lcd(13, 12, 11, 10, 9, 8);//RS,EN,D4,D5,D6,D7  
#include <SFE_BMP180.h>  
#include <Wire.h>  
//create an SFE_BMP180 object, here called "pressure":  
SFE_BMP180 pressure;  
#define ALTITUDE 222.0 // altitude of Delhi in meters  
void setup(){  
  Serial.begin(9600);  
  Serial.println("BMP180 Measurements");  
  lcd.begin(20, 4);  
  lcd.setCursor(0, 0);  
  lcd.print("BMP180 Measurements");  
  lcd.setCursor(0, 1);  
  lcd.print(" 1. Temperature");  
  lcd.setCursor(0, 2);  
  lcd.print(" 2. Pressure");  
  lcd.setCursor(0, 3);  
  lcd.print(" 3. Altitude");  
  delay (5000);  
  lcd.clear();//clear display  
  // initialize the sensor (it is important to get calibration values stored on the device).  
  if (pressure.begin())  
  Serial.println("BMP180 init success");  
  else{  
    // oops, something went wrong, this is usually a connection problem,  
      // see the comments at the top of this sketch for the proper connections.  
    Serial.println("BMP180 init fail\n\n");  
    while(1); // pause forever.  
  }  
}  
void loop(){  
  char status;  
  double T,P,p0,a;  
  // loop here getting pressure readings every 10 seconds.  
    // if you want sea-level-compensated pressure, as used in weather reports,  
    // you need to find dinamically altitude of place.  
    // here, we are using constant called ALTITUDE in this sketch:  
  Serial.println();  
  Serial.print("provided altitude: ");  
  lcd.setCursor(0, 0);  
  lcd.print("Altitude: ");  
  Serial.print(ALTITUDE,0);  
  Serial.print(" meters, ");  
  Serial.print(ALTITUDE*3.28084,0);  
  lcd.print(ALTITUDE*3.28084,0);  
  Serial.println(" feet");  
  lcd.print(" ft");  
  // start a temperature measurement:  
    // if request is successful, the number of ms to wait is returned.  
    // if request is unsuccessful, 0 is returned.  
  status = pressure.startTemperature();  
  if (status != 0){  
    // wait for the measurement to complete:  
    delay(status);  
    // retrieve the completed temperature measurement:  
      // note that the measurement is stored in the variable T.  
      // function returns 1 if successful, 0 if failure.  
    status = pressure.getTemperature(T);  
    if (status != 0){  
      // Print out the measurement:  
      Serial.print("temperature: ");  
      Serial.print(T,2);  
      Serial.print(" deg C, ");  
      Serial.print((9.0/5.0)*T+32.0,2);  
      Serial.println(" deg F");  
      lcd.setCursor(0, 1);  
      lcd.print("Temperature: ");  
      lcd.print(T,2);  
      lcd.print(" C ");  
      // start a pressure measurement:  
          // the parameter is the oversampling setting, from 0 to 3 (highest res, longest wait).  
          // if request is successful, the number of ms to wait is returned.  
          // if request is unsuccessful, 0 is returned.  
      status = pressure.startPressure(3);  
      if (status != 0){  
        // wait for the measurement to complete:  
        delay(status);  
            // Retrieve the completed pressure measurement:  
            // Note that the measurement is stored in the variable P.  
            // Note also that the function requires the previous temperature measurement (T).  
            // (If temperature is stable, you can do one temperature measurement for a number of pressure measurements.)  
            // Function returns 1 if successful, 0 if failure.  
        status = pressure.getPressure(P,T);  
        if (status != 0){  
          // print out the measurement:  
          Serial.print("absolute pressure: ");  
          Serial.print(P,2);  
          Serial.print(" mb, ");  
          Serial.print(P*0.0295333727,2);  
          Serial.println(" inHg");  
          lcd.setCursor(0, 2);  
          lcd.print("Abs. Pr.: ");  
          lcd.print(P*0.0295333727,2);  
          lcd.print(" inHg");  
            // The pressure sensor returns absolute pressure, which varies with altitude.  
                // To remove the effects of altitude, use the sea level function and your current altitude.  
                // This number is commonly used in weather reports.  
                // Parameters: P = absolute pressure in mb, ALTITUDE = current altitude in m.  
                // Result: p0 = sea-level compensated pressure in mb  
          p0 = pressure.sealevel(P,ALTITUDE); // we are at 222 meters (Delhi)  
          Serial.print("relative (sea-level) pressure: ");  
          Serial.print(p0,2);  
          Serial.print(" mb, ");  
          Serial.print(p0*0.0295333727,2);  
          Serial.println(" inHg");  
          lcd.setCursor(0, 3);  
          lcd.print("Rel. Pr.: ");  
          lcd.print(p0*0.0295333727,2);  
          lcd.print(" inHg");  
          // On the other hand, if you want to determine your altitude from the pressure reading,  
          // use the altitude function along with a baseline pressure (sea-level or other).  
          // Parameters: P = absolute pressure in mb, p0 = baseline pressure in mb.  
          // Result: a = altitude in m.  
          a = pressure.altitude(P,p0);  
          Serial.print("computed altitude: ");  
          Serial.print(a,0);  
          Serial.print(" meters, ");  
          Serial.print(a*3.28084,0);  
          Serial.println(" feet");  
        }  
        else   
          Serial.println("error retrieving pressure measurement\n");  
      }  
      else   
        Serial.println("error starting pressure measurement\n");  
    }  
    else  
      Serial.println("error retrieving temperature measurement\n");  
  }  
  else  
    Serial.println("error starting temperature measurement\n");  
  delay(5000); // Pause for 5 seconds.  
}

从 https://github.com/LowPowerLab/SFE_BMP180 下载SFE_BMP180-master.zip文件

在编译上面的代码之前添加SFE_BMP180-master zip文件，否则会生成错误SFE_BMP180.h：没有这样的文件或目录。

要添加zip文件，请单击：Sketch -> Include Library -> Add .ZIP Library… 并添加下载的SFE_BMP180-master zip。

添加zip文件