double Fahrenheit(double celsius) { return 1.8 * celsius + 32; } //攝氏溫度度轉化為華氏溫度
double Kelvin(double celsius) { return celsius + 273.15; } //攝氏溫度轉化為開氏溫度
// 露點(點在此溫度時,空氣飽和并產生露珠) // 參考:wahiduddin點net/calc/density_algorithms.htm double dewPoint(double celsius, doublehumidity) //humidity是濕度,celsius是攝氏溫度 { 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); }
// 快速計算露點,速度是5倍dewPoint()(上面函數的結果) double dewPointFast(double celsius, doublehumidity) { 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.h>
dht11 DHT11;
#define DHT11PIN 2
void setup() //設置一些參數 { Serial.begin(9600); Serial.println("DHT11 TEST PROGRAM "); Serial.print("LIBRARY VERSION: "); Serial.println(DHT11LIB_VERSION); Serial.println(); }
void loop() { Serial.println("\n"); //換行
intchk = DHT11.read(DHT11PIN);
Serial.print("Read sensor: "); //讀取傳感器 switch (chk) { case DHTLIB_OK: Serial.println("OK"); break; case DHTLIB_ERROR_CHECKSUM: Serial.println("Checksumerror"); break; case DHTLIB_ERROR_TIMEOUT: Serial.println("Time outerror"); break; default: Serial.println("Unknownerror"); 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); } |