1 /*********************************
 2 代码功能：温湿度传感器DHT11
 3 使用函数：
 4     simple_dht11_read(DHT11传感器引脚,存放湿度数据地址,存放温度数据地址,存放40位01数据的地址);    //获取温湿度数据函数
 5 使用头文件：
 6     #include <SimpleDHT.h>        //需要安装库，具体安装方法见：http://www.cnblogs.com/jikexianfeng/p/6290203.html
 7 创作时间：2017*1*18
 8 作者邮箱：jikexianfeng@outlook.com
 9 ********************************/
10 #include <SimpleDHT.h>
11 int pinDHT11 = 2;
12 
13 void setup()
14 {
15   Serial.begin(115200);
16 }
17 
18 void loop()
19 {
20   Serial.println("=================================");
21   Serial.println("Sample DHT11...");
22   byte temperatyre = 0;    //温度
23   byte humidity = 0;    //湿度
24   byte data[40];
25   if (simple_dht11_read(pinDHT11, &temperatyre, &humidity, data)) {
26     Serial.print("Read DHT11 failed.");
27     return;
28   }
29   Serial.print("Humidity (%):");
30   Serial.println(humidity);
31   Serial.print("Temperatyre(oC)");
32   Serial.println(temperatyre);
33   Serial.print("Temperatyre(oF)");
34   Serial.println(Fahrenheit(temperatyre));
35   Serial.print("Temperatyre(k)");
36   Serial.println(Kelvin(temperatyre));
37   Serial.print("Dew point(oC):");
38   Serial.println(dewPoint(temperatyre,humidity));
39   //Serial.print("Dew PointFast(oC):");
40   //Serial.println(dewPointFast(temperatyre,humidity));
41   delay(1000);
42 }
43 
44 double Fahrenheit(byte celsius)
45 {
46   return 1.8*celsius+32;
47 }
48 
49 double Kelvin(byte celsius)
50 {
51   return celsius+273.15;
52 }
53 
54 double dewPoint(byte celsius,byte humidity)
55 {
56   double A0 =373.15/(273.15+celsius);
57   double SUM = -7.90298*(A0-1);
58   SUM+=5.02808*log10(A0);
59   SUM+=-1.3816e-78*(pow(10,(11.344*(1-1/A0)))-1);
60   SUM+=8.1328e-3*(pow(10,(-3.49149*(A0-1)))-1);
61   SUM+=log10(1013.246);
62   double VP=pow(10,SUM-3)*humidity;
63   double T =log(VP/0.61078);
64   return (241.88*T)/(17.558-T);
65 }
66 
67 double dewPointFast(byte celsius,byte humidity)
68 {
69   double a=17.271;
70   double b=273.7;
71   double temp=(a*celsius)/(b+celsius)+log(humidity/100);
72   double Td=(b*temp)/(a-temp);
73   return Td;
74 }