#include <Arduino.h>
#include "DHTesp.h"
#include <WiFi.h>
#include <HTTPClient.h>
#include <AsyncTCP.h>
#include <ESPAsyncWebServer.h>
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
// Defining the WiFi channel speeds up the connection:
#define WIFI_CHANNEL 6
#define DHTPIN 27
#define DHTTYPE DHT22
DHTesp dhtSensor;
// Create AsyncWebServer object on port 80
AsyncWebServer server(80);
String readDHTTemperature() {
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
// Read temperature as Celsius (the default)
// float t = dht.readTemperature(); use for real sensor
float t = dhtSensor.getTemperature();
// Read temperature as Fahrenheit (isFahrenheit = true)
//float t = dht.readTemperature(true);
// Check if any reads failed and exit early (to try again).
if (isnan(t)) {
Serial.println("Failed to read from DHT sensor!");
return "--";
}
else {
Serial.println(t);
return String(t);
}
}
String readDHTHumidity() {
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
//float h = dht.readHumidity();
float h = dhtSensor.getHumidity();
if (isnan(h)) {
Serial.println("Failed to read from DHT sensor!");
return "--";
}
else {
Serial.println(h);
return String(h);
}
}
String readStockPrice() {
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
//float h = dht.readHumidity();
float p = 129;
return String(p);
}
const char index_html[] PROGMEM = R"rawliteral(
<!DOCTYPE HTML><html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<script src="https://kit.fontawesome.com/a47d5e547d.js" crossorigin="anonymous"></script>
<style>
html {
font-family: Arial;
display: inline-block;
margin: 0px auto;
text-align: center;
}
h2 { font-size: 3.0rem; }
p { font-size: 3.0rem; }
.units { font-size: 1.2rem; }
.dht-labels{
font-size: 1.5rem;
vertical-align:middle;
padding-bottom: 15px;
}
</style>
</head>
<body>
<h2>REA Smart Lamp</h2>
<p>
<i class="fas fa-thermometer-half" style="color:#059e8a;"></i>
<span class="dht-labels">Temperature</span>
<span id="temperature">%TEMPERATURE%</span>
<sup class="units">°C</sup>
</p>
<p>
<i class="fas fa-tint" style="color:#00add6;"></i>
<span class="dht-labels">Humidity</span>
<span id="humidity">%HUMIDITY%</span>
<sup class="units">%</sup>
</p>
<p>
<i class="fas fa-chart-line" style="color:#D4583E;"></i>
<span class="dht-labels">Stock Price $</span>
<span id="price">%STOCK%</span>
</p>
</body>
<script>
setInterval(function ( ) {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("temperature").innerHTML = this.responseText;
}
};
xhttp.open("GET", "/temperature", true);
xhttp.send();
}, 10000 ) ;
setInterval(function ( ) {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("humidity").innerHTML = this.responseText;
}
};
xhttp.open("GET", "/humidity", true);
xhttp.send();
}, 10000 ) ;
setInterval(function ( ) {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("price").innerHTML = this.responseText;
}
};
xhttp.open("GET", "/price", true);
xhttp.send();
}, 10000 ) ;
</script>
</html>)rawliteral";
// Replaces placeholder with DHT values
String processor(const String& var) {
//Serial.println(var);
if (var == "TEMPERATURE") {
return readDHTTemperature();
}
else if (var == "HUMIDITY") {
return readDHTHumidity();
}
else if (var == "STOCK") {
return readStockPrice();
}
return String();
}
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
Serial.println("Hello, ESP32!");
dhtSensor.setup(DHTPIN, DHTesp::DHT22);
// Connect to Wi-Fi
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi..");
}
// Print ESP32 Local IP Address
Serial.println(WiFi.localIP());
// Route for root / web page
server.on("/", HTTP_GET, [](AsyncWebServerRequest * request) {
request->send_P(200, "text/html", index_html, processor);
});
server.on("/temperature", HTTP_GET, [](AsyncWebServerRequest * request) {
request->send_P(200, "text/plain", readDHTTemperature().c_str());
});
server.on("/humidity", HTTP_GET, [](AsyncWebServerRequest * request) {
request->send_P(200, "text/plain", readDHTHumidity().c_str());
});
server.on("/price", HTTP_GET, [](AsyncWebServerRequest * request) {
request->send_P(200, "text/plain", readStockPrice().c_str());
});
// Start server
server.begin();
}
void loop() {
// put your main code here, to run repeatedly:
delay(10); // this speeds up the simulation
}