Arduino DHT Sensor

#include "DHT.h"  //FOR DHT SENSOR#include <SPI.h>  //FOR SD CARD#include <SD.h>   //FOR SD CARD#include <OneWire.h>#include <DallasTemperature.h>

const int chipSelect = 4;  //Pin to SD card
#define DHTPIN 2     // Digital pin connected to the DHT sensor
// Data wire is plugged into port 7 on the Arduino for water temp probe#define ONE_WIRE_BUS 7// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)OneWire oneWire(ONE_WIRE_BUS);
// Pass our oneWire reference to Dallas Temperature.DallasTemperature sensors(&oneWire);
// Uncomment whatever type you're using!//#define DHTTYPE DHT11   // DHT 11#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321//#define DHTTYPE DHT21   // DHT 21 (AM2301)
// Initialize DHT sensor.
void setup() {  // start serial port  Serial.begin(9600);
  dht.begin();  Serial.println(F("DHT AM2302 test!"));  sensors.begin();  Serial.println("Water Probe Sensor");    while (!Serial) {    ; // wait for serial port to connect. Needed for native USB port only  }
   Serial.print("Initializing SD card...");
  // see if the card is present and can be initialized:  if (!SD.begin(chipSelect)) {    Serial.println("Card failed, or not present");    // don't do anything more:    while (1);  }

void loop() {
  // make a string for assembling the data to log:  //String dataString = "";
   // Wait a few seconds between measurements.  delay(9000);    sensors.requestTemperatures(); // Send the command to get temperatures  // After we got the temperatures, we can print them here.  // We use the function ByIndex, and as an example get the temperature from the first sensor only.  float tempC = sensors.getTempCByIndex(0);   // Reading temperature or humidity takes about 250 milliseconds!  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)  float h = dht.readHumidity();  // Read temperature as Celsius (the default)  float t = dht.readTemperature();  // Read temperature as Fahrenheit (isFahrenheit = true)  float f = dht.readTemperature(true);
  // Check if any reads failed and exit early (to try again).  if (isnan(h) || isnan(t) || isnan(f)) {    Serial.println(F("Failed to read from DHT sensor!"));    return;  }
  // Compute heat index in Fahrenheit (the default)  float hif = dht.computeHeatIndex(f, h);  // Compute heat index in Celsius (isFahreheit = false)  float hic = dht.computeHeatIndex(t, h, false);
  Serial.print(F("Humidity: "));  Serial.print(h);  Serial.print(F("%  Temperature: "));  Serial.print(t);  Serial.print(F("°C "));  Serial.print(f);  Serial.print(F("°F  Heat index: "));  Serial.print(hic);  Serial.print(F("°C "));  Serial.print(hif);  Serial.print(F("°F"));  Serial.print(F(" Water Temp: "));  Serial.print(tempC);  Serial.println(F("°C "));

    // open the file. note that only one file can be open at a time,  // so you have to close this one before opening another.  File dataFile ="datalog.txt", FILE_WRITE);
  // if the file is available, write to it:  if (dataFile) {    dataFile.print(F("Humidity: "));    dataFile.print (h);  dataFile.print(F("%  Temperature: "));  dataFile.print(t);  dataFile.print(F("°C "));  dataFile.print(f);  dataFile.print(F("°F  Heat index: ")); dataFile.print(hic);  dataFile.print(F("°C "));  dataFile.print(hif);  dataFile.print(F("°F"));  dataFile.print(F(" Water Temp: "));  dataFile.print(tempC);  dataFile.println(F("°C "));    dataFile.close();    // print to the serial port too:    //Serial.println(dataString);  }  // if the file isn't open, pop up an error:  else {    Serial.println("error opening datalog.txt");  }


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