95 lines
2.4 KiB
Arduino
95 lines
2.4 KiB
Arduino
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double Fahrenheit(double celsius)
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{
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return 1.8 * celsius + 32;
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} //摄氏温度度转化为华氏温度
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double Kelvin(double celsius)
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{
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return celsius + 273.15;
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} //摄氏温度转化为开氏温度
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// 露点（点在此温度时，空气饱和并产生露珠）
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// 参考: http://wahiduddin.net/calc/density_algorithms.htm
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double dewPoint(double celsius, double humidity)
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{
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double A0= 373.15/(273.15 + celsius);
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double SUM = -7.90298 * (A0-1);
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SUM += 5.02808 * log10(A0);
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SUM += -1.3816e-7 * (pow(10, (11.344*(1-1/A0)))-1) ;
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SUM += 8.1328e-3 * (pow(10,(-3.49149*(A0-1)))-1) ;
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SUM += log10(1013.246);
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double VP = pow(10, SUM-3) * humidity;
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double T = log(VP/0.61078); // temp var
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return (241.88 * T) / (17.558-T);
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}
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// 快速计算露点，速度是5倍dewPoint()
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// 参考: http://en.wikipedia.org/wiki/Dew_point
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double dewPointFast(double celsius, double humidity)
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{
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double a = 17.271;
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double b = 237.7;
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double temp = (a * celsius) / (b + celsius) + log(humidity/100);
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double Td = (b * temp) / (a - temp);
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return Td;
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}
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#include <dht11.h>
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dht11 DHT11;
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#define DHT11PIN 2
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void setup()
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{
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Serial.begin(9600);
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Serial.println("DHT11 TEST PROGRAM ");
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Serial.print("LIBRARY VERSION: ");
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Serial.println(DHT11LIB_VERSION);
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Serial.println();
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}
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void loop()
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{
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Serial.println("\n");
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int chk = DHT11.read(DHT11PIN);
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Serial.print("Read sensor: ");
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switch (chk)
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{
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case DHTLIB_OK:
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Serial.println("OK");
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break;
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case DHTLIB_ERROR_CHECKSUM:
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Serial.println("Checksum error");
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break;
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case DHTLIB_ERROR_TIMEOUT:
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Serial.println("Time out error");
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break;
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default:
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Serial.println("Unknown error");
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break;
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}
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Serial.print("Humidity (%): ");
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Serial.println((float)DHT11.humidity, 2);
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Serial.print("Temperature (oC): ");
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Serial.println((float)DHT11.temperature, 2);
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Serial.print("Temperature (oF): ");
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Serial.println(Fahrenheit(DHT11.temperature), 2);
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Serial.print("Temperature (K): ");
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Serial.println(Kelvin(DHT11.temperature), 2);
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Serial.print("Dew Point (oC): ");
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Serial.println(dewPoint(DHT11.temperature, DHT11.humidity));
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Serial.print("Dew PointFast (oC): ");
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Serial.println(dewPointFast(DHT11.temperature, DHT11.humidity));
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delay(2000);
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}
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