Documentation

// DHT22 Temperature & Humidity Sensor - Arduino Example
// Requires Adafruit DHT sensor library

#include <DHT.h>

#define DHTPIN 2          // DATA pin connected to digital 2
#define DHTTYPE DHT22     // DHT 22 (AM2302)

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  Serial.println("DHT22 starting...");
  dht.begin();
}

void loop() {
  delay(2000);  // DHT22 needs ~2s between readings

  float h = dht.readHumidity();
  float t = dht.readTemperature();

  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.println(" *C");
}

#!/usr/bin/env python3
# DHT22 - Raspberry Pi Example
# Install: pip install adafruit-circuitpython-dht
# Also: sudo apt install libgpiod2

import time
import board
import adafruit_dht

# DATA pin connected to GPIO 4 (physical pin 7)
dht = adafruit_dht.DHT22(board.D4)

while True:
    try:
        temp = dht.temperature
        humid = dht.humidity
        print(f"Temp: {temp:.1f} C  Humidity: {humid:.1f}%")
    except RuntimeError as e:
        # Reading failed (timing issue), just retry
        print("Read error:", e.args[0])
    time.sleep(2.0)

# DHT22 - Pico MicroPython Example
# Uses built-in dht module (no install needed)

from machine import Pin
import dht
import time

sensor = dht.DHT22(Pin(15))

while True:
    try:
        sensor.measure()
        t = sensor.temperature()
        h = sensor.humidity()
        print("Temp: {:.1f} C  Humidity: {:.1f}%".format(t, h))
    except OSError as e:
        print("Failed to read sensor:", e)
    time.sleep(2)

// DHT22 - ESP32 Arduino Example
// Requires Adafruit DHT sensor library

#include <DHT.h>

#define DHTPIN 4          // DATA pin connected to GPIO 4
#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  dht.begin();
}

void loop() {
  delay(2000);
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println("DHT22 read failed");
    return;
  }
  Serial.printf("Temp: %.1f C  Humidity: %.1f%%\n", t, h);
}