Introduction: NodeMCU With Blynk App/Server

What is Blynk and how it works, watch their campaign video !

First, As it turns you can program the NodeMCU with Arduino IDE check the video above.

Here is the Written Tutorial for the setup :


  1. Breadboard
  2. Two NodeMCUs 1.0
  3. Arduino Uno or any other type
  4. Jumpers
  5. USB Power Cables

Step 1: Here Is an Overview

1st - Download Blynk application

2nd- add your devices as shown in the video and copy the Authentication Token created for our device as we will use it later in the code

- In this project we are setting two NodeMCU devices and connecting them to oue WiFi network , then start to sending data (Integer/Character) from NodeMCU 1 to NodeMCU 2

- Also we will connect Arduino UNO to NodeMCU 2 through wired serial communication

- the data recieved from NodeMCU 1 will be sent to the Arduino UNO at the end and we can use this single to toggle a LED or any other thing

- we will display on the Blynk Application wether the LED is ON or OFF

Step 2: NodeMCU 1 Code

no wiring is needed for Node MCU 1 as it will connected to wifi and just send "1" or "0"
all we need is the Authentication Token we created

Built in LED in D2 is used as indication for successful WiFi Connection

then start writing the code above

Step 3: NodeMCU 2 + Arduino Codes

NodeMCU 2 - we used D7 as RX and D8 as TX , built in LED in D13 is used as an indication

Arduino - we used Pin 8 as RX and Pin 9 as TX


  • D7 in NodeMCU to Pin 9 in Arduino
  • D8 in NodeMCU to Pin 8 in Arduino
  • VIN in NodeMCU to 5V in Arduino
  • GND in NodeMCU to GND in Arduino (Common Ground)

After setting all connections , please start downloading the code above in the NodeMCU 2

Step 4: Arduino Code

Here is the code needed to recieve the data from NodeMCU 2 to Arduino

you can connect a LED to Pin 13