Wokwi - Online ESP32, STM32, Arduino Simulator

#include <WiFi.h>
#include "DHT.h"
#define DHTPIN 13
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);
float temperature;
float humidity;
// Replace with your network credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";
// Set web server port number to 80
WiFiServer server(80);
// Variable to store the HTTP request
String header;
// Current time
unsigned long currentTime = millis();
// Previous time
unsigned long previousTime = 0;
// Define timeout (example: 2000ms = 2s)
const long timeoutTime = 2000;
void setup() {
Serial.begin(115200);
dht.begin();
// Connect to Wi-Fi network with SSID and password
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
// Print local IP address and start web server
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
server.begin();
}
void loop(){
float humidity = dht.readHumidity();
float temperature = dht.readTemperature();
// Listen for incoming clients
WiFiClient client = server.available();
// If a new client connects,
if (client) {
currentTime = millis();
previousTime = currentTime;
Serial.println("New Client.");
// print a message out in the serial port
String currentLine = "";
// make a String to hold incoming data from the client
while (client.connected() && currentTime - previousTime <= timeoutTime) {
// loop while the client's connected
currentTime = millis();
if (client.available()) {
// if there's bytes to read from the client,
char c = client.read();
// read a byte, then
Serial.write(c);
// print it out the serial monitor
header += c;
if (c == '\n') {
// if the byte is a newline character
/* if the current line is blank, you got two newline characters in a row.
that's the end of the client HTTP request, so send a response: */
if (currentLine.length() == 0) {
/* HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
and a content-type so the client knows what's coming, then a blank line: */
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println("Connection: close");
client.println();
// Display the HTML web page
client.println("<!DOCTYPE html><html>");
client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
client.println("<link rel=\"icon\" href=\"data:,\">");
// CSS to style the on/off buttons
// Feel free to change the background-color and font-size
client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
client.println("</style></head>");
// Web Page Heading
client.println("<body><h1>ESP32 Web Server</h1>");
client.println("<p><h2>Temperature Value " + String(temperature) + "</h2></p>");
client.println("<p><h2>Humidity Value " + String(humidity) + "</h2></p>");
client.println("</body></html>");
// The HTTP response ends with another blank line
client.println();
// Break out of the while loop
break;
} else {
// if you got a newline, then clear currentLine
currentLine = "";
}
} else if (c != '\r') {
// if you got anything else but a carriage return character,
currentLine += c;
// add it to the end of the currentLine
}
}
}
// Clear the header variable
header = "";
// Close the connection
client.stop();
Serial.println("Client disconnected.");
Serial.println("");
}
}