Arduino ESP8266 NodeMCU in Access Point mode with Web Server to control an RGB Led

Introduction

See Introduction of Internet of the Things in previous article.

Objective

Demonstrate how to use the Arduino ESP8266 NodeMCU as an Access Point with Web Server to Control an RGB Led.

Software

• Driver
  • CP210x USB to UART Bridge VCP Drivers
• Integrated Development Environment
  • Arduino IDE

Hardware

• Arduino ESP8266 NodeMCU

  $9.49 ESP8266 NodeMCU in

• Breadboard mini

  

• Led RGB

  

• Resistances (330 ohms)

  

Pinout diagram

Code

• Repository in Github
  • Fritzing

  

  • Arduino_ESP8266_NodeMCU_Access_Point_Web_Server_Led_RGB.fzz

• Arduino IDE

  • Board

    1. Add url board

       

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

    2. Install board

       

  • Configuration

    

• Arduino_ESP8266_NodeMCU_Access_Point_Web_Server_Led_RGB

  /*
  Arduino_ESP8266_NodeMCU_Access_Point_Web_Server_Led_RGB.c 
  v0.0.1 - 2019-02-21 - nelbren.com
  */
  #include <ESP8266WiFi.h>
  #include <WiFiClient.h>
  #include <ESP8266WebServer.h>
      
  const char* ssid = "ESPWebServer";
  const char* password = "12345678";
  
  WiFiServer server(80);
  
  int ledRed =   D0; // D0 = GPIO16
  int ledGreen = D1; // D1 = GPIO05
  int ledBlue =  D2; // D2 = GPIO04
  
  int estado = 0;
  char *msg;
  
  void setup(void){
    Serial.begin(9600);
    Serial.println("");
    WiFi.mode(WIFI_AP);
    WiFi.softAP(ssid, password);
      
    IPAddress myIP = WiFi.softAPIP(); //Get IP address
    Serial.print("HotSpt IP:");
    Serial.println(myIP);
  
    pinMode(ledGreen, OUTPUT);
    digitalWrite(ledGreen, HIGH);
  
    pinMode(ledBlue, OUTPUT);
    digitalWrite(ledBlue, HIGH);
  
    pinMode(ledRed, OUTPUT);
    digitalWrite(ledRed, HIGH);
  
    server.begin();
    Serial.println("HTTP server started");
  }
  
  void red(void) {
    digitalWrite(ledRed, HIGH);
    digitalWrite(ledGreen, LOW);
    digitalWrite(ledBlue, LOW);
    Serial.println("RED!");
  }
  
  void green(void) {
    digitalWrite(ledGreen, HIGH);
    digitalWrite(ledRed, LOW);
    digitalWrite(ledBlue, LOW);
    Serial.println("GREEN!");
  }
  
  void yellow(void) {
    digitalWrite(ledRed, HIGH);
    digitalWrite(ledGreen, HIGH);
    digitalWrite(ledBlue, LOW);
    Serial.println("YELLOW!");
  }
  
  void blue(void) {
    digitalWrite(ledBlue, HIGH);
    digitalWrite(ledRed, LOW);
    digitalWrite(ledGreen, LOW);
    Serial.println("BLUE!");
  }
  
  void white(void) {
    digitalWrite(ledBlue, HIGH);
    digitalWrite(ledRed, HIGH);
    digitalWrite(ledGreen, HIGH);  
    Serial.println("WHITE!");
  }
  
  void black(void) {
    digitalWrite(ledRed, LOW);
    digitalWrite(ledGreen, LOW);
    digitalWrite(ledBlue, LOW);
    Serial.println("BLACK!");
  }
  
  void demo(void) {
    Serial.println("DEMO:");
    for(int i = 0; i < 6; i++) {
      switch (i) {
        case 0: red(); break;
        case 1: green(); break;
        case 2: yellow(); break;
        case 3: blue(); break;
        case 4: white(); break;
        case 5: black(); break;
      }
      delay(1000);
    }
  }
  
  void loop(void){
    WiFiClient client = server.available();
    if (!client) {
      return;
    }
  
    Serial.println("new client");
  
    while(client.connected() && !client.available())
    {
      delay(1);
    }
  
    String request = client.readStringUntil('\r');
    Serial.println(request);
    client.flush();
  
    String mode = "";
        
    if (request.indexOf("/BLACK") != -1) {
      black();
      mode = "BLACK";
    }
  
    if (request.indexOf("/RED") != -1) {
      red();
      mode = "RED";
    }
        
    if (request.indexOf("/GREEN") != -1) {
      green();
      mode = "GREEN";
    }
        
    if (request.indexOf("/YELLOW") != -1) {
      yellow();
      mode = "YELLOW";
    }
        
    if (request.indexOf("/BLUE") != -1) {
      blue();
      mode = "BLUE";
    }
        
    if (request.indexOf("/WHITE") != -1) {
      white();
      mode = "WHITE";
    }
  
    if (request.indexOf("/DEMO") != -1) {
      demo();
      mode = "DEMO";
    }
  
    // Return the response
    client.println("HTTP/1.1 200 OK");
    client.println("Content-Type: text/html");
    client.println(""); // do not forget this one
    client.println("<!DOCTYPE HTML>");
    client.println("<html>");
  
    //client.println("<head><meta http-equiv='refresh' content='1'></head>");
  
    if (mode == "") {
      client.println("<h1>MODE: Waiting for instructions from Cyberdyne Systems</h1>");
    } else {  
      client.println("<h1>MODE: ");
      client.println(mode);
      client.println("</h1>");
    }
    client.println("<hr>");
    client.println("<h2>");
    client.println("<a href=\"/RED\">RED</a><br>");
    client.println("<a href=\"/GREEN\">GREEN</a><br>");
    client.println("<a href=\"/YELLOW\">YELLOW</a><br>");
    client.println("<a href=\"/BLUE\">BLUE</a><br>");
    client.println("<a href=\"/WHITE\">WHITE</a><br>");
    client.println("<a href=\"/BLACK\">BLACK</a><br>");
    client.println("<br>");
    client.println("<a href=\"/DEMO\">DEMO</a><br>");
    client.println("</h2>");
    client.println("<hr>");
    client.println("<center>");
    client.println("<h3><a href='https://nelbren.com'>nelbren.com</a>&copy;2019</h3>");
    client.println("</center>");
    client.println("</html>");
  
    delay(1);
    Serial.println("Client disconnected");
    Serial.println("");
  }