Skip to main content

Internet controlled switch using NodeMCU and MQTT

Hello Sailors! Today we are going to build an internet controlled switch. Woah! Internet controlled Switch, sounds cool! With this switch we will be able to switch ON/OFF our appliances from anywhere in the world like a BOSS.

What's NodeMCU?

NodeMCU is an open-source IOT module which is based on ESP-12 module, we can create WIFI Access point with this or connect this to our wifi router and then control relays, servos etc. over internet or wifi.

What's MQTT?

MQTT is a light weight messaging protocol for small sensors and mobile devices. It consists of a broker(can be on cloud or local network) which routes the messages from publisher to subscriber.

In this project, we will be sending message to NodeMCU which is connected to the internet. The NodeMCU then switches the relay ON/OFF based on the message received. Sounds genius!

How this works?

We are going to create an MQTT topic and make our NodeMCU it's subscriber and MQTT dash, the publisher. MQTT  dash will publish the commands to broker which will be routed to the NodeMCU connected to the internet. NodeMCU will translate and command and act accordingly.

Let's begin...

Things we need:

Note: After completing CloudMQTT registration create a topic over there e.g. "uniqueID/topic". We shall be using this topic to communicate with NodeMCU.

Circuit Setup:


Connection details:

  • D5 pin of NodeMCU is connected to input/signal pin of Relay.
  • 3v3 pin of NodeMCU to 3v3 source.
  • Vcc of relay to 5V source.
  • All ground pins are connected to common ground.

Android Setup:

Now, to communicate with the device we need to set up our android/iphone. We have downloaded the MQTT Dash application from Google Play Store.

Open the app, add a dashboard using + sign on top right and fill in the details from CloudMQTT console page:

Name: Super Awesome Switch
Address: e.g. m45.cloudmqtt.com
Port: e.g. 1883
UserName: Will be provided at CloudMQTT Console
Password: Will be provided at CloudMQTT Console

Click save button on top right, a new dashboard is now available. Open this dashboard, it will connect and display a blank page. Again, click on + sign now to add Switch on screen. It will ask for few details:

Name: Relay 1
Sub: uniqueID/topic

We will leave other 2 check boxes checked and ON as 1 and OFF as 0. Click Save on top right and we are done with App configuration.

Code Setup:

We are set to upload our code to NodeMCU. Connect NodeMCU to computer with Micro USB cable, and open Arduino IDE. Now we shall check the port connected and the device selected is NodeMCU 1.0 from the Tools menu in Arduino and finally upload our code. Code on GitHub
Lines to be manipulated are mentioned within the code as comments.

Once the code is uploaded to NodeMCU, open Serial Monitor to check the print commands. If it is connected to CloudMQTT server, open your MQTT dash app in your Android phone and try switching ON/OFF the relay, it will work like a BOSS. Now, we can remove the usb cable and connect our NodeMCU to 3V3 source.

So, guys that's it for today. I hope you enjoyed the post, feel free to ask questions or provide suggestions. There is a lot of room for improvement in code and circuit.

Till then, Happy IOTing.
Labels:

Comments

Post a Comment

Popular posts from this blog

Time scheduled electric switch controlled with Blynk app

Most of the times when we go out of home for some days, we think of having some device that could switch ON/OFF (let's say)  Refrigerator  (or any other important appliance)   for some hours during the day. Today, we are going to make such time scheduled electric switch which switches ON/OFF at times which we set the in our Blynk app. Woah! Let's begin! Things we need: Hardware: 5V relay NodeMCU Jumper wires Breadboard 3V3 and 5V power source Electrical Wires Software: Arduino IDE BLYNK app It's circuit is same as we have created for our Smart Switch . So, if you already have that circuit set up, go ahead with Blynk app set up and Start playing. Circuit: Connections: D5 pin of NodeMCU connects to IN1 pin of 5V relay. 3V3 of NodeMCU connects to 3V3 powers source and GND to GND. Vcc of relay connects to 5V source and GND to GND. Live wire is connected directly to appliance. Neutral wire from source comes to relay NC pin and another w...
5 comments
Read more

Karna - The hapless Mahabharata Warrior

“Karma is a bitch.”  These must be the truest words ever spoken. Karna was so unfortunate because of his Karma. In his previous birth, Karna was a demon by name “Dambhodbhava”. He was an Asura, who like every other asura, wanted to be powerful and had a ridiculous desire to become Immortal. So, one fine day, he started to pray for Sun God “Surya Deva”. Lord Surya was impressed by his devotion and intensity of his “ Tapas  (Deep meditation)” and asked him what his desire was. Dambhodbhava who was greedy for power asked Surya to grant him the one boon no one could grant i.e. Immortality. “Everything that takes birth must die” . This was the First Law Of the Universe and Surya told the asura, he can ask for anything except Immortality. Dambodhbhava was crestfallen as he thought that all the Tapas was a waste of time. Dambodhbhava unwilling to give up, was lost in thought for a long time. He was determined to go home immortal one way or the other. So, he ...
2 comments
Read more

Automate irrigation system over internet

Hello Sailors! We are back with one more awesome IOT project where we are going to automate irrigation system. The system  can be used in homes to water the plants any time and can also be scheduled so even if you forget to water plants (lazy like me), just schedule the device and your plants get water regularly. That's another great use of IOT, aah! Overview We are going to control an AC water pump using NodeMCU/ESP8266 and blynk application. The Blynk app will have a switch controlling the pump to switch ON/OFF and an Eventor widget to schedule our pump switching with time. This way plants can be irrigated by manual switching or by scheduling with time. Things we need Hardware NodeMCU/ESP8266 5V relay Water Pump Water pipes (0.5 inch) Water flow splitter Water container Pipe clamps Jumper Wires 5V and 3.3V power supply Software Arduino IDE Blynk app If you have already setup the  Time Scheduled electric switch   go ahead to setup the water...
3 comments
Read more