Nick Pettefar asked 3 years ago
I added another sensor, an LDR, but it doesn’t refresh automatically, even though I copied the DHT22 code.
/*********
Rui Santos
Complete project details at https://randomnerdtutorials.com
*********/
// Import required libraries
#include “WiFi.h”
IPAddress local_IP(10,10,19,7);
IPAddress gateway(10,10,19,100);
IPAddress subnet(255, 255, 255, 0);
IPAddress primaryDNS(10,10,19,144);
IPAddress secondaryDNS(8, 8, 8, 8);
#include “ESPAsyncWebServer.h”
#include <Adafruit_Sensor.h>
#include <DHT.h>
// Replace with your network credentials
const char* ssid = “Nick”;
const char* password = “********”;
#define DHTPIN 27 // Digital pin connected to the DHT sensor
// Uncomment the type of sensor in use:
//#define DHTTYPE DHT11 // DHT 11
#define DHTTYPE DHT22 // DHT 22 (AM2302)
//#define DHTTYPE DHT21 // DHT 21 (AM2301)
DHT dht(DHTPIN, DHTTYPE);
const int LDR = A0;
// 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();
// 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.print(“Temperature = “); 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();
if (isnan(h)) {
Serial.println(“Failed to read from DHT sensor!”);
return “–“;
}
else {
Serial.print(“Humidity = “); Serial.println(h);
return String(h);
}
}
String readLDR() {
int LightLevel = analogRead(LDR) / 33;
Serial.print(“Light Level = “); Serial.println(LightLevel);
return String(LightLevel);
}
const char index_html[] PROGMEM = R”rawliteral(
<!DOCTYPE HTML><html>
<head>
<meta name=”viewport” content=”width=device-width, initial-scale=1″>
<link rel=”stylesheet” href=”https://use.fontawesome.com/releases/v5.7.2/css/all.css” integrity=”sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr” crossorigin=”anonymous”>
<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>Nick’s ESP32 DHT22 Server</h2>
<H3>Radio Room sensor</H3>
<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>
<span style=”font-size: 260%; color: gold;position: relative;top: 44px;”>*</span>
<span class=”dht-labels”>Light Level</span>
<span id=”humidity”>%LIGHTLEVEL%</span>
<sup class=”units”>%</sup>
</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(“lightlevel”).innerHTML = this.responseText;
}
};
xhttp.open(“GET”, “/lightlevel”, 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 == “LIGHTLEVEL”){
return readLDR();
}
return String();
}
void setup(){
// Serial port for debugging purposes
Serial.begin(115200);
dht.begin();
// Connect to Wi-Fi
WiFi.config(local_IP, gateway, subnet, primaryDNS, secondaryDNS);
WiFi.begin(ssid, 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(“/lightlevel”, HTTP_GET, [](AsyncWebServerRequest *request){
request->send_P(200, “text/plain”, readLDR().c_str());
});
// Start server
server.begin();
}
void loop(){
}
Sara Santos Staff answered 3 years ago
Hi.
In your code, search for this section:
<p> <span style="font-size: 260%; color: gold;position: relative;top: 44px;">*</span> <span class="dht-labels">Light Level</span> <span id="humidity">%LIGHTLEVEL%</span> THE ID IS WRONG <sup class="units">%</sup> </p><p>
Then replace it with this:
<p> <span style="font-size: 260%; color: gold;position: relative;top: 44px;">*</span> <span class="dht-labels">Light Level</span> <span id="lightlevel">%LIGHTLEVEL%</span> <sup class="units">%</sup> </p>
Basically, you forgot to change the id of the place that holds the light reading.
Now, it should work.
Regards,
Sara