查看“Arduino系列教程七：DHT11-温湿度传感器”的源代码



本教程使用的温湿度传感器模块为：
Temperature-Humidity Sensor
，先晒张美图：


[[File:092556c533snq1q39l7qjr.jpg]]

模块采用的温湿度传感器为：DHT11，DHT11 数字温湿度传感器是一款含有已校准数字信号输出的温湿度复
合传感器。它包括一个电阻式感湿元件和一个 NTC 测温元件。每个 DHT11 传
感器都在极为精确的湿度校验室中进行校准。校准系数以程序的形式储存在
OTP 内存中，传感器内部在检测信号的处理过程中要调用这些校准系数,用户
无需重新校准。单线制串行接口，使系统集成变得简易快捷。超小的体积、
极低的功耗，信号传输距离可达 20 米以上。


<b>硬件准备：</b>
* UNO PLUS开发板* Temperature-Humidity Sensor模块* I/O Expansion Shield扩展板
<b>硬件连接：</b>


[[File:094828elw4wl34q4qp3lff.jpg]]


将UNO PLUS的电压配置为5V， 模块引脚连接如下：


VCC - 5V

GND - GND

DOUT - D2



<b>程序：</b>
<syntaxhighlight lang="python">
double Fahrenheit(double celsius) 
{
        return 1.8 * celsius + 32;
}   

double Kelvin(double celsius)
{
        return celsius + 273.15;
}    

double dewPoint(double celsius, double humidity)
{
        double A0= 373.15/(273.15 + celsius);
        double SUM = -7.90298 * (A0-1);
        SUM += 5.02808 * log10(A0);
        SUM += -1.3816e-7 * (pow(10, (11.344*(1-1/A0)))-1) ;
        SUM += 8.1328e-3 * (pow(10,(-3.49149*(A0-1)))-1) ;
        SUM += log10(1013.246);
        double VP = pow(10, SUM-3) * humidity;
        double T = log(VP/0.61078);   // temp var
        return (241.88 * T) / (17.558-T);
}

double dewPointFast(double celsius, double humidity)
{
        double a = 17.271;
        double b = 237.7;
        double temp = (a * celsius) / (b + celsius) + log(humidity/100);
        double Td = (b * temp) / (a - temp);
        return Td;
}

#include

dht11 DHT11;

#define DHT11PIN 2

void setup()
{
  Serial.begin(9600);
  Serial.println("DHT11 TEST PROGRAM ");
  Serial.print("LIBRARY VERSION: ");
  Serial.println(DHT11LIB_VERSION);
  Serial.println();
}

void loop()
{
  Serial.println("\n");

  int chk = DHT11.read(DHT11PIN);

  Serial.print("Read sensor: ");
  switch (chk)
  {
    case DHTLIB_OK: 
                Serial.println("OK"); 
                break;
    case DHTLIB_ERROR_CHECKSUM: 
                Serial.println("Checksum error"); 
                break;
    case DHTLIB_ERROR_TIMEOUT: 
                Serial.println("Time out error"); 
                break;
    default: 
                Serial.println("Unknown error"); 
                break;
  }

  Serial.print("Humidity (%): ");
  Serial.println((float)DHT11.humidity, 2);

  Serial.print("Temperature (oC): ");
  Serial.println((float)DHT11.temperature, 2);

  Serial.print("Temperature (oF): ");
  Serial.println(Fahrenheit(DHT11.temperature), 2);

  Serial.print("Temperature (K): ");
  Serial.println(Kelvin(DHT11.temperature), 2);

  Serial.print("Dew Point (oC): ");
  Serial.println(dewPoint(DHT11.temperature, DHT11.humidity));

  Serial.print("Dew PointFast (oC): ");
  Serial.println(dewPointFast(DHT11.temperature, DHT11.humidity));
  delay(2000);
}</syntaxhighlight>
 



<b><b><b>现象：</b></b></b>


<b><b>
[[File:094406d25zt25g8nxpnpxb.jpg]]
</b></b>
<b>
</b>
<b>附件：</b>
<a class="attach" href="portal.php?mod=attachment&amp;id=30" target="_blank">dht11.zip