DHT11

/*
The DHT11 is a digital temperature and humidity sensor that communicates over a 1-wire protocol. Here's an example code in Arduino that reads the temperature and humidity from the sensor:

Note: This code assumes that the DHT11 sensor is connected to pin 2 of the Arduino board. If you're using a different pin, you'll need to modify the DHTPIN definition accordingly. Also, the sensor may take up to 2 seconds to provide an accurate reading, so a delay is added before each reading.
*/

#include <DHT.h>

#define DHTPIN 2     // the pin connected to the sensor
#define DHTTYPE DHT11   // specify the sensor type

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  dht.begin();
}

void loop() {
  delay(2000);  // wait 2 seconds between readings

  // read the temperature and humidity from the sensor
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();

  // print the temperature and humidity
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");
}