Controlling LED from AWS using NodeMCU & Arduino IDE

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Suryateja Pericherla Categories: IoT Lab. No Comments

In this article we will learn how to implement Controlling LED from AWS using NodeMCU & Arduino IDE. If your are new to Internet of Things (IoT), learn about IoT by visiting our Internet of Things tutorial for beginners.

Contents

1 Aim of Experiment
2 Components Required
3 Connections Diagram (Schematic)
4 Code (C++/Arduino IDE)
5 Video Explanation

Aim of Experiment

To control home devices (LED) using a self-hosted page on Amazon AWS

Components Required

NodeMCU – 1
LED – 1
330Ω Resistor – 1
Breadboard – 1

Connections Diagram (Schematic)

Code (C++/Arduino IDE)

#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>

/*Put your SSID & Password*/
const char* ssid = "ssid";  // Enter SSID here
const char* password = "password";  //Enter Password here

ESP8266WebServer server(80);

uint8_t LEDpin = D2;
bool LEDstatus = LOW;

void setup() 
{
  Serial.begin(9600);
  delay(100);
  pinMode(LEDpin, OUTPUT);

  Serial.println("\nConnecting to ");
  Serial.println(ssid);

  //connect to your local wi-fi network
  WiFi.begin(ssid, password);

  //check wi-fi is connected to wi-fi network
  while (WiFi.status() != WL_CONNECTED) {
  delay(1000);
  Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected..!");
  Serial.print("Got IP: ");  
  Serial.println(WiFi.localIP());

  server.on("/", handle_OnConnect);
  server.on("/ledon", handle_ledon);
  server.on("/ledoff", handle_ledoff);
  server.onNotFound(handle_NotFound);

  server.begin();
  serial.println("HTTP server started");
}

void loop() 
{
  server.handleClient();
  if(LEDstatus)
  digitalWrite(LEDpin, HIGH);
  else
  digitalWrite(LEDpin, LOW);
}

void handle_OnConnect() 
{
  LEDstatus = LOW;
  server.send(200, "text/html", SendHTML(false)); 
}

void handle_ledon() 
{
  LEDstatus = HIGH;
  server.send(200, "text/html", SendHTML(true)); 
}

void handle_ledoff() 
{
  LEDstatus = LOW;
  server.send(200, "text/html", SendHTML(false)); 
}

void handle_NotFound()
{
  server.send(404, "text/plain", "Not found");
}

String SendHTML(uint8_t led)
{
  String ptr = "<!DOCTYPE html>\n";
  ptr +="<html>\n";
  ptr +="<head>\n";
  ptr +="<title>LED Control</title>\n";
  ptr +="</head>\n";
  ptr +="<body>\n";
  ptr +="<h1>LED</h1>\n";
  ptr +="<p>Click to switch LED on and off.</p>\n";
  ptr +="<form method=\"get\">\n";
  if(led)
  ptr +="<input type=\"button\" value=\"LED OFF\" 	onclick=\"window.location.href='/ledoff'\">\n";
  else
  ptr +="<input type=\"button\" value=\"LED ON\" 	onclick=\"window.location.href='/ledon'\">\n";
  ptr +="</form>\n";
  ptr +="</body>\n";
  ptr +="</html>\n";
  return ptr;
}

Extra Instructions

Step 1: Dump the code to NodeMCU and connect to Wi-Fi network
Step 2: See the serial monitor for IP address assigned to NodeMCU
Step 3: Install ngrok software on your laptop (your laptop should also be connected to same Wi-Fi network)
Step 4: Create a tunnel using ngrok and the Auth token provided by ngrok using the command given below:
ngrok tcp 192.168.43.65:80 –authtoken <AUTHTOKEN>
Step 5: Enjoy controlling your NodeMCU from Internet

Video Explanation

References

Suryateja Pericherla

Suryateja Pericherla, at present is a Research Scholar (full-time Ph.D.) in the Dept. of Computer Science & Systems Engineering at Andhra University, Visakhapatnam. Previously worked as an Associate Professor in the Dept. of CSE at Vishnu Institute of Technology, India.

He has 11+ years of teaching experience and is an individual researcher whose research interests are Cloud Computing, Internet of Things, Computer Security, Network Security and Blockchain.

He is a member of professional societies like IEEE, ACM, CSI and ISCA. He published several research papers which are indexed by SCIE, WoS, Scopus, Springer and others.

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