Published January 1, 2019

IoT | Connecting and Interfacing a DHT 11 with WeMos D1 Mini

A simple project to learn IoT by connecting a DHT11 temperature and humidity sensor with WeMos D1 Mini and interfacing the data to Blynk.

BeginnerShowcase (no instructions)1 hour25,290

IoT | Connecting and Interfacing a DHT 11 with WeMos D1 Mini

Things used in this project

Hardware components

Espressif Wemos D1 Mini

DHT11 Temperature & Humidity Sensor (4 pins)

Jumper wires (generic)

Breadboard (generic)

Micro-USB to USB Cable (Generic)

Software apps and online services

Arduino IDE

Blynk

Story

This project will help you to learn IoT on a simple way, by just connecting the DHT11 temperature and humidity sensor to WeMos D1 Mini and displaying the output on your smartphone using the Blynk app.

Step 1: Install the Software

To Install the Arduino IDE, download from this link: https://www.arduino.cc/en/Main/Software
To Install Blynk, download from Google Play Store.

For board and library:

ESP8266 Board: http://arduino.esp8266.com/stable/package_esp8266com_index.json
DHT11 Library: https://github.com/sarful/DHT_monitoring_In_Blynk_app_Use_NodeMcu/blob/master/DHT%20Library.zip
Simple Timer: https://github.com/jfturcot/SimpleTimer

Step 2: Wiring

Connect the wire, the DHT11 has 4 or 3 Pin includes VCC, Data, and Ground pin.

VCC Pin of DHT11 to 5V Pin of WeMos D1 Mini
Data Pin of DHT11 to D4 Pin of WeMos D1 Mini
GND Pin of DHT11 to GND Pin of WeMos D1 Mini

Wiring Diagram

Step 3: Set Up Blynk

After download and installing the Blynk Apps from Google Play Store, you need to make your IoT project apps in Blynk. Here the steps.

Login to your Blynk App. If you don't have one, just create it, it's free
Create a new project, give your project a name, choose your device : WeMos D1 Mini, connetion type : WiFi
Then you will receive a notification about Auth Token, just select OK. Your Auth Token wil be sent to your Email
Then you see your workspace. Go to Widget Box, and select 'Gauge'. Select the Gauge Widget twice, the first one will be set as the Temperature gauge, the second one will be set as the Humidity gauge.
After two gauge selected, go to the gauge setting.

For the first gauge:

Name: Temperature

Input: Virtual, V0

Label: °C / °F

Reading Rate: 1 Sec

For the second gauge:

Name: Humidity

Input: Virtual, V1

Label: RH

Reading Rate: 1 Sec

Step 4: Code

Paste the code that i've attached, and change the auth code in the program that i've attached with your own auth code (check your Email for your auth code).

Auth Code

The Result

Blynk

Thank you! If you have any suggestions, please write in the comment section. Happy learning.

Code

The code

#define BLYNK_PRINT Serial
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include "DHT.h"
#include <SimpleTimer.h> 
#define DHTTYPE DHT11
#define dht_dpin D4
DHT dht(dht_dpin, DHTTYPE); 
SimpleTimer timer;
char auth[] = "Your Auth Code";
char ssid[] = "Your WiFI";
char pass[] = "Your Wifi Password";
float t;
float h;

void setup()
{
    Serial.begin(9600);
    Blynk.begin(auth, ssid, pass);
    dht.begin();
    timer.setInterval(2000, sendUptime);
}

void loop()
{
  Blynk.run();
  timer.run();
}

void sendUptime()
{
  float h = dht.readHumidity();
  float t = dht.readTemperature(); 
  Serial.println("Humidity and temperature\n\n");
  Serial.print("Current humidity = ");
  Serial.print(h);
  Serial.print("%  ");
  Serial.print("temperature = ");
  Serial.print(t); 
  Blynk.virtualWrite(V0, t);
  Blynk.virtualWrite(V1, h); 
}

Credits

Fattah

15 projects • 17 followers

Electronics Engineer - Embedded System Enthusiast

IoT | Connecting and Interfacing a DHT 11 with WeMos D1 Mini

Things used in this project

Hardware components

Software apps and online services

Story

Step 1: Install the Software

Step 2: Wiring

Step 3: Set Up Blynk

Step 4: Code

The Result

Schematics

Wiring Diagram

Code

The code

Credits

Fattah

Comments

Embed the widget on your own site

IoT | Connecting and Interfacing a DHT 11 with WeMos D1 Mini

IoT | Connecting and Interfacing a DHT 11 with WeMos D1 Mini

Things used in this project

Hardware components

Software apps and online services

Story

Step 1: Install the Software

Step 2: Wiring

Step 3: Set Up Blynk

Step 4: Code

The Result

Schematics

Wiring Diagram

Code

The code

Credits

Fattah

Comments

Related channels and tags