The DHT11 is a basic, low-cost digital temperature and humidity sensor.It's fairly simple to use, but requires careful timing to grab data.
Technical Details
Low Cost 3 to 5V power and I/O 2.5mA max current Good for 20-80% humidity readings with 5% accuracy Good for 0-50°C temperature readings ±2°C accuracy No more than 1 Hz sampling rate (once every second) Body size 15.5mm x 12mm x 5.5mm
Test sketch
//
// FILE: dht11_test1.pde
// PURPOSE: DHT11 library test sketch for Arduino
//
#include <dht11.h>
dht11 DHT;
#define DHT11_PIN 7
void setup(){
Serial.begin(9600);
Serial.println("DHT TEST PROGRAM ");
Serial.print("LIBRARY VERSION: ");
Serial.println(DHT11LIB_VERSION);
Serial.println();
Serial.println("Type,\tstatus,\tHumidity (%),\tTemperature (C)");
}
void loop(){
int chk;
Serial.print("DHT11, \t");
chk = DHT.read(DHT11_PIN); // READ DATA
switch (chk){
case DHTLIB_OK:
Serial.print("OK,\t");
break;
case DHTLIB_ERROR_CHECKSUM:
Serial.print("Checksum error,\t");
break;
case DHTLIB_ERROR_TIMEOUT:
Serial.print("Time out error,\t");
break;
default:
Serial.print("Unknown error,\t");
break;
}
// DISPLAT DATA
Serial.print(DHT.humidity,1);
Serial.print(",\t");
Serial.println(DHT.temperature,1);
delay(1000);
}
