2.- Web Server in ESP32 with a web page.
Through this page we can turn on-off an LED. Check the status of the LED.
- ESP32 Station of Router.
- Install Web Server in ESP32, port 80.
- Set a web page in Web Server.
- We can turn on/off LED2 (LED2 is a BUILT-IN LED in Board) through a web page.
- We can also check the status of LED2.
// Juan A. Villalpando.
// KIO4.COM
// Enciende y apaga LED. Botones.
#include <WiFi.h>
const char* ssid = "Name_WiFi_net";
const char* password = "Password_WiFi_net";
WiFiServer server(80); // Port 80
#define LED2 2 // LED2 is a Built-in LED.
String estado = "";
int wait30 = 30000; // time to reconnect when connection is lost.
void setup() {
Serial.begin(115200);
pinMode(LED2, OUTPUT);
// Connect WiFi net.
Serial.println();
Serial.print("Connecting with ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("Connected with WiFi.");
// Start Web Server.
server.begin();
Serial.println("Web Server started.");
// Esta es la IP
Serial.print("This is IP to connect to the WebServer: ");
Serial.print("http://");
Serial.println(WiFi.localIP());
}
void loop() {
// If disconnected, try to reconnect every 30 seconds.
if ((WiFi.status() != WL_CONNECTED) && (millis() > wait30)) {
Serial.println("Trying to reconnect WiFi...");
WiFi.disconnect();
WiFi.begin(ssid, password);
wait30 = millis() + 30000;
}
// Check if a client has connected..
WiFiClient client = server.available();
if (!client) {
return;
}
Serial.print("New client: ");
Serial.println(client.remoteIP());
// Espera hasta que el cliente envíe datos.
// while(!client.available()){ delay(1); }
/////////////////////////////////////////////////////
// Read the information sent by the client.
String req = client.readStringUntil('\r');
Serial.println(req);
// Make the client's request.
if (req.indexOf("on2") != -1) {digitalWrite(LED2, HIGH); estado = "ON";}
if (req.indexOf("off2") != -1){digitalWrite(LED2, LOW); estado = "OFF";}
if (req.indexOf("consulta") != -1){
if (digitalRead(LED2)){estado = "LED2 now is ON";}
else {estado = "LED2 now is OFF";}
}
//////////////////////////////////////////////
// WEB PAGE. ////////////////////////////
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println(""); // Important.
client.println("<!DOCTYPE HTML>");
client.println("<html>");
client.println("<head><meta charset=utf-8></head>");
client.println("<body><center><font face='Arial'>");
client.println("<h1>Servidor web con ESP32.</h1>");
client.println("<h2><font color='#009900'>KIO4.COM - Juan A. Villalpando</font></h2>");
client.println("<h3>Página web.</h3>");
client.println("<br><br>");
client.println("<a href='on2'><button>Click to ON LED2</button></a>");
client.println("<a href='off2'><button>Click to OFF LED2</button></a>");
client.println("<a href='consulta'><button>Consult status LED2</button></a>");
client.println("<br><br>");
client.println(estado);
client.println("</font></center></body></html>");
Serial.print("Client disconnected: ");
Serial.println(client.remoteIP());
client.flush();
client.stop();
}
Now in a Browser, we write the local IP of the server. We will get a page with three buttons, we can turn on-off and check the status of LED2.
- If we wanted to obtain the source code of the page, we would put these blocks:
