Internet Controlled LED Using NodeMCU




About: STEM Educator | Robotics Trainer | R & D Engineer | 3D Printing Enthusiast |Loves DIY Projects and LEGO

The Internet of Things (IoT) is a system of interrelated computing devices, mechanical and digital machines, objects, animals or people that are provided with unique identifiers and the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction.

In this instructable, we'll be making a simple IoT project.Web page controlled LED using NodeMCU connected on a local network.

NodeMCU is an open source IoT platform. It includes firmware which runs on the ESP8266 WiFi SoC from Espressif, and hardware which is based on the ESP-12 module. The term "NodeMcu" by default refers to the firmware rather than the dev kits. The firmware ESP8266 uses the Lua scripting language. It is based on the Lua project and built on the Espressif Non-OS SDK for ESP8266. It uses many open source projects, such as Lua-cjson and spiffs. LUA based interactive firmware for Expressif ESP8622 Wi-Fi SoC, as well as an open-source hardware board that contrary to the $3 ESP8266 Wi-Fi modules includes a CP2102 TTL to USB chip for programming and debugging, is breadboard-friendly, and can simply be powered via its micro USB port.


  • Wi-Fi Module – ESP-12E module similar to the ESP-12 module but with 6 extra GPIOs.
  • USB – micro USB port for power, programming and debugging
  • Headers – 2x 2.54mm 15-pin header with access to GPIOs, SPI, UART, ADC, and power pinsMisc – Reset and Flash buttons
  • Power – 5V via micro USB port

Step 1: Materials Required

  1. ESP8266 NodeMCU
  2. Breadboard
  3. LED
  4. Jumper Wires
  5. Arduino IDE

Step 2: Installing NodeMCU Board Package

  1. Open up Arduino IDE. Go to Files-> Preferences. Enter into Additional Board Manager URLs field
  2. Now go to Tools->Boards->Board Manager, and search for ESP8266 and install the package.

Step 3: Pin Connections

  1. D7 of NodeMCU to LED's +ve.
  2. G of NodeMCU to LED's -ve.

Step 4: Source Code

In code

change ssid to your ssid name

and Password to your SSID's password

const char* ssid = "MODI";//your ssid

const char* password = "8826675619";//Your Password

Step 5: Uploading the Code

When u have successfully built your connection on the breadboard and write coding, you have to upload the coding into the NodeMCU by using a micro USB.

Now, go to Tools > Board > ESP8266 Modules and you can see many options for ESP8266. Select "NodeMCU 1.0 (ESP-12E Module). Next, select your port. If you cant recognize your port, go to the Control Panel > System > Device Manager > Port and update your USB driver.

Now upload the code to the board.

Step 6: Controlling the LED

  • Now open up your Serial Monitor, and not down the URL.
  • Now put the URL in your phone's browser.
  • A page will open having two buttons ON and OFF.
  • If everything is correct when you press ON the LED will light up and when you press OFF the LED will turn off.



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    18 Discussions


    21 days ago

    Hello, modi. 1992.
    I have done all such things and connected my nodemcu with my mobile hotspot, but in serial monitor of Arduino ide is not show anything.


    Question 5 months ago on Step 6


    I did exactly as above.

    I even got the web server, with the LED ON and OFF buttons.

    But, while executing the ON button, the LED does not turn ON. I even tried using a resistor, and have also checked if the LED works fine. Can you please help me with this?

    I'm really excited about the whole project, and to work on a bit of modifications too if this works fine.



    Question 5 months ago

    I cant get this to work :(, I installed everything exactly like you said, and I get these errors:

    error: espcomm_upload_mem failed

    error: espcomm_open failed


    Question 6 months ago

    Code is not showing any error , but when we try to open the link it show " This page isn't working" ,

    and below it comes as "XXX.XXX.XX.XXX didn't send any data.ERR_EMPTY_RESPONSE

    Kindly help us as soon as possible we are troubleshooting it since long.


    Question 11 months ago

    Hello Modi,

    First of all, thank you so much for this detailed article on ESP8266.

    I did built as you mentioned and it's working fine.

    I have one query.

    When I connect my NodeMCU and laptop to my mobile hot-spot.

    I can made LED ON and OFF from laptop and another mobile browser when all these are connected to same hot-spot.

    How can I connect from different mobile (having internet connection) and turn ON and OFF this ESP module LED?

    Mobile hotspot: having IP

    Laptop is connected to this Wi-Fi hot--spot.

    Another mobile when connected to this Wi-Fi hot-spot then I can control LED

    Third mobile having data connection (from different service provider) when try to browse same URL, can't open the webpage.

    Am I missing something here?

    Please can you help?

    1 answer

    1 year ago

    Hello Modi, great project. However, I have the following problem. If I do not press a button in the browser for 10 minutes, I lose the connection. I only get a connection when I upload the code again. Do you have this problem? I would be grateful for a solution.

    Best regards

    3 replies

    Reply 10 months ago

    Little change in the sketch will solve your issue. I think you should make the connection to the router/hotspot in the loop() so that it can automatically reconnects if the connection is lost at some point.


    Reply 1 year ago

    Hi David

    I am not facing such issue with my project.I'll try and figure out to solve your problem and come back with the solution


    10 months ago

    Very nicely drafted !


    Question 10 months ago on Step 6


    is it neccesary in this project that both nodemcu as well as browser must be connected to same internet network.


    11 months ago on Step 4

    What if I want to control multiple leds and have different buttons for each of them like I can control each of the led separately ?


    Question 11 months ago

    how do i modify the code to be able to controll multiple leds instead of only one


    11 months ago

    Hi Modi, I do exactly what you say in this post and i have done uploading. Then, i have this problem in the following picture. Btw, thank you for this great project. Hope to see your reply soon.

    1 reply

    Reply 11 months ago

    Please change the baud rate of serial monitor to 115200