NodeMCU based 8 relay board for Internet of Things (IoT applications)




What is NodeMCU??
Detailed information about this can be found at  https://nodemcu.readthedocs.io/en/master/.
Basically it is an IoT board at very (!) cheap price.  

Why to use relay boards
The board can be used or IoT applications which involve switching devices as primary application.
The relay board has the wifi on board so it will minimize the number of wires in your IoT project. Total 8 GPIOs are used for controlling 8 relays. The unused pins are soldered to male headers and kept open for other applications and connecting different sensors. The basic pin diagram of NodeMCU can be found at [NodeMCU documentation]--- https://nodemcu.readthedocs.io/en/master/

NodeMCU can be programmed using Arduino as well.
Download Arduino IDE first.

Connect NodeMCU using the micro usb cable. Install drivers for CH340G or CP2102 (depending on the controller on your NodeMCU).

In the boards manager (Arduino IDE) use this URL.

http://arduino.esp8266.com/stable/package_esp8266com_index.json

Install ESP8266 libraries.
Select Board as NodeMCU 1.0 (ESP12E module)
Select correct COM port.

Your NodeMCU is ready to work now.




The android application can be developed using MIT app inventor and google firebase or Android Studio. MIT app inventor
Android studio

Link to github repository

NodeMCU on GitHub

Here I have uploaded all the developments I am currently doing with the NodeMCU..
Programs are compiled and tested. Developers are welcome for their tests..


Specifications
  1. Compact form factor (10cm X 10cm).
  2. Relays rated for 10A.
  3. Unused GPIOs are open for developers.
  4. Rx, Tx headers for connecting to Arduino.
  5. You can use your own NodeMCU board.
  6. Toshiba Optoisolator for reliability.
  7. Each module is tested after soldering.
  8. Seperate LED for indication of relay ON/OFF.
  9. External supply for relay (~9 V DC is fine).
  10. Onboard regulator AMS1117 (for getting fixed 5V going as Vin to NodeMCU.)
Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. I sell on Tindie
Location: Bengaluru, Karnataka, India

Comments

  1. SmartGuysSeptember 23, 2021 at 12:09 AM

    Nice blog! Shelly 1 gives you high security and provides device access control from anywhere in the world.
    Buy shelly wifi relay online

    ReplyDelete

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