ard_DHT11

I connected the DHT11 Digital Humidity and Temperature Sensor to the Arduino.   Sensor pin, VCC, and Ground from Left to Right.  I installed the DHT.h library to the IDE.  Download the latest copy.   Unzip and copy to your IDE Library directory.  

dht-sensor-library

DHT11 Specifications:
  • Operating Voltage: 3.5V to 5.5V.
  • Operating current: 0.3mA (measuring) 60uA (standby)
  • Output: Serial data.
  • Temperature Range: 0°C to 50°C.
  • Humidity Range: 20% to 90%
  • Resolution: Temperature and Humidity both are 16-bit.
  • Accuracy: ±1°C and ±1%

Arduino 4 Slave

#include <Wire.h>
#include <DHT.h>
#include <DHT.h>
#define Type DHT11
int sensorPin = 8;
DHT HumTemp(sensorPin, Type);
float humidity;
float tempC;
float tempF;
int setTime = 1000;


void setup() {
  Serial.begin(9600);
  Wire.begin(0x4);                // join i2c bus with address #4
  Wire.onReceive(receiveEvent); // register event  

HumTemp.begin();
delay(setTime);

  
}

void loop() {
humidity=HumTemp.readHumidity();
tempC=HumTemp.readTemperature();
tempF=HumTemp.readTemperature(true);
Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print("%");
Serial.print(" Temperature: ");
Serial.print(tempC);
Serial.print("C ");
Serial.print(" Temperature: ");
Serial.print(tempF);
Serial.println("F ");
delay(setTime);


  
}

// function that executes whenever data is received from master
// this function is registered as an event, see setup()
void receiveEvent(int howMany) {
}