Simulating ESP32 + DHT22 with Wokwi

A cross-platform guide for makers: run a virtual ESP32 + DHT22 sensor in your browser—no hardware required!

Introduction

Welcome, digital tinkerers, IoT enthusiasts, and curious minds! In this guide, we'll explore how to simulate an ESP32 microcontroller connected to a DHT22 temperature & humidity sensor using the magic of Wokwi.

Why simulate? Simple:

  • No physical hardware needed
  • Fast and safe testing
  • Prototype from anywhere

Whether you're a student, hobbyist, or professional prototyper, let's dive into your first simulated DHT22 experiment—complete with randomized data. Buckle up! 🚀

Prerequisites

You only need a browser to run Wokwi simulations. If you plan to extend your project later with local or cloud logging, you might need developer tools (we’ll cover that in future guides).

Step-by-Step: Simulate ESP32 + DHT22

Go to the ESP32 + DHT22 Template on Wokwi and click “Fork” to create your own editable version.

The ESP32 is wired to a DHT22 sensor as follows:

  • Data Pin: GPIO 15
  • VCC: 3.3V
  • GND: Ground

Wokwi lets you fake sensor data! Click the DHT22, then in the UI: 


"humidity": "random(40, 80)",
"temperature": "random(20, 35)"

Now your sensor returns a new random value each time it's read.

Use this Arduino sketch in your sketch.ino:


#include "DHT.h"
#define DHTPIN 15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

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

void loop() {
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  
  Serial.print("Temperature: ");
  Serial.print(temp);
  Serial.print(" °C\tHumidity: ");
  Serial.print(hum);
  Serial.println(" %");

  delay(2000);
}

Then click “Start Simulation” to see the readings flow.

Data Viewing

The Wokwi Serial Monitor emulates how the Arduino IDE would show your sensor data. Every 2 seconds, you’ll see new temperature and humidity readings like: 


Temperature: 27.45 °C   Humidity: 65.23 %

Wrap-Up

Simulating an ESP32 + DHT22 in Wokwi grants you the freedom to:

  • Prototype without physical hardware
  • Quickly test sensor logic
  • Control your "environment" with random data

Perfect for teaching, debugging, or planning a bigger IoT build. Next steps might include adding more sensors, storing data locally, or sending it to a cloud service.

Happy simulating!