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Temperature & Humidity Sensor (DHT11) | NexaLearn IoT Lab | NexaLearn

Sensors25 دقيقة

Temperature & Humidity Sensor (DHT11)

How to sense the surrounding room environment. An introduction to using pre-built libraries.

Lesson Content

Some sensors send their data as simple analog signals, but DHT11 sends a very complex digital data packet. Instead of writing 100 lines to decode it, we use Libraries. A library is code written by other programmers that saves us work. You need to download the DHT library from the Library Manager in the Arduino IDE.

Components Needed

Arduino Unoحساس DHT11مقاومة 10K

Wiring Notes

VCC to 5V. Data pin to pin 2 with a 10K pull-up resistor to VCC (some DHT11 modules come with 3 pins and a built-in resistor). GND to GND.

Code Example

#include <DHT.h>
#define DHTPIN 2
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  dht.begin();
}
void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) { Serial.println("Failed"); return; }
  Serial.print("Temp: "); Serial.print(t);
  Serial.print(" C, Humidity: "); Serial.println(h);
  delay(2000);
}

Common Mistakes

Trying to read the sensor too frequently. DHT11 needs at least 2 seconds between each reading.

Try in Simulator

Open in Wokwi Simulator

Next Lesson

Servo Motors (Precise Angle Control)