ESP32 DHT11 Sensor Module with Arduino IDE

#Introduction

This project uses a DHT11 sensor to measure temperature and humidity.
The sensor sends digital data to a microcontroller like Arduino or ESP32.
It is easy to use and does not require analog conversion.
This setup is commonly used in weather monitoring and automation projects.

#Required Components

• ESP32 Board
• DHT11 Sensor Module
• Jumper Wires
• Breadboard (optional)

#Pinout

#Circuit Diagram / Wiring

• DHT11 → ESP32
  • VCC → 3.3V
  • GND → GND
  • DATA → GPIO 4

#Code / Programming

• Install Required Library (via Arduino Library Manager).
• Go to the “Libraries” tab on the left-hand side of the screen.
• Click on the “Library Manager” button (book icon) at the top of the Libraries tab.
• In the Library Manager window, type “DHT” in the search bar.
• Locate the “DHT sensor library” library by Adafruit click on the “Install” button next to it.
• Wait for the library to be installed, and you’re ready to use the DHT library in your projects.

/*********************************************************************** * Filename : DHT11_Sensor.ino * Author : www.oceanlabz.in * Modification: 1/4/2025 ***********************************************************************/

#include "DHT.h"

#define DHTPIN 4 // Data pin connected to GPIO 4 #define DHTTYPE DHT11 // DHT11 sensor

DHT dht(DHTPIN, DHTTYPE);

void setup() { Serial.begin(115200); Serial.println("DHT11 Sensor with ESP32");

dht.begin(); }

void loop() { float humidity = dht.readHumidity(); float temperature = dht.readTemperature(); // Celsius

// Check if any reads failed if (isnan(humidity) || isnan(temperature)) { Serial.println("Failed to read from DHT sensor!"); return; }

Serial.print("Temperature: "); Serial.print(temperature); Serial.print(" °C | ");

Serial.print("Humidity: "); Serial.print(humidity); Serial.println(" %");

delay(2000); // DHT11 needs ~2 seconds delay }

#Explanation

• Reads temperature and humidity data from the DHT11 sensor using GPIO pin on the ESP32.
• Processes the sensor data and checks for any reading errors.
• Displays the temperature (°C) and humidity (%) values on the Serial Monitor every 2 seconds.

#Troubleshooting

• If no data is shown, check wiring (VCC → 3.3V, GND → GND, DATA → correct GPIO) and ensure the correct pin is defined in code.
• If showing “Failed to read,” verify library installation and add a 10k pull-up resistor (for non-module DHT11).
• If readings are unstable, ensure proper power supply and add a delay of at least 2 seconds between readings.