How to Monitor DHT Sensor Values on the Blynk App Using Arduino

In this tutorial, we will walk you through the steps to monitor DHT (Digital Humidity and Temperature) sensor values on the Blynk app using an Arduino board. This project allows you to remotely monitor the temperature and humidity data from the DHT sensor on your smartphone.

Materials Needed:

- Arduino board (e.g., Uno, Nano)

- DHT11 or DHT22 sensor

- Jumper wires

- Breadboard

- USB cable

- Internet connection

- Blynk app installed on your smartphone

Step 1: Setting Up the Hardware

1. Connect the DHT Sensor to the Arduino:

- DHT11/DHT22 Pin Configuration:

- VCC to 5V or 3.3V pin on Arduino

- GND to GND pin on Arduino

- Data pin to a digital pin on Arduino (e.g., D2)

DHT Sensor   ->   Arduino
   ------------------------
   VCC          ->   5V
   GND          ->   GND
   DATA         ->   D2

2. Wiring Diagram:

Ensure you connect the pins correctly to avoid any damage to the sensor or the Arduino.

Step 2: Setting Up the Blynk App

1. Download and Install the Blynk App:

- Available on Google Play Store (Android) and Apple App Store (iOS).

2. Create a New Project:

- Open the Blynk app and create a new project.

- Choose your device (e.g., Arduino Uno).

- Note the Auth Token sent to your email.

3. Add Widgets:

- Add a “Gauge” or “Value Display” widget for temperature.

- Add a “Gauge” or “Value Display” widget for humidity.

- Configure the widgets to display values from virtual pins (e.g., V5 for temperature and V6 for humidity).

Step 3: Programming the Arduino

1. Install the Required Libraries:

- Open the Arduino IDE and install the following libraries:

- Blynk library

- DHT sensor library

Sketch -> Include Library -> Manage Libraries...

- Search for "Blynk" and install it.

- Search for "DHT sensor library" and install it.

2. Write the Arduino Code:

- Use the following sample code given below.

- Replace `YourWiFiSSID`, `YourWiFiPassword`, and `YourAuthToken` with your actual WiFi credentials and Blynk Auth Token.

3. Upload the Code:

- Connect your Arduino to your computer via USB and upload the code.

Step 4: Monitoring the Data

1. Open the Blynk App:

- Start the project by pressing the play button in the Blynk app.

2. View the Sensor Data:

- The temperature and humidity values should now appear on the widgets you configured.

- You can now monitor the DHT sensor values in real-time from your smartphone.