Wokwi - Online ESP32, STM32, Arduino Simulator

#include <WiFi.h>
#include <WiFiClient.h>
#include <WebServer.h>
#include <uri/UriBraces.h>
// <-------- Start Display -------->

#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <Wire.h>

#define SCREEN_WIDTH 128 
#define SCREEN_HEIGHT 64 

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
// <-------- End Display -------->
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
// Defining the WiFi channel speeds up the connection:
#define WIFI_CHANNEL 6

// <-------- Start Temperature Variables -------->

// Der NTC ist mit dem GPIO 27 verbunden 
const int ntcPin = 32;

// Variable um den Wert des NTC zu speichern
int ntcValue = 0;

double Vs = 5;                // Ausgangsspannung
double adcMax = 4095.0;       // Analog-Digital Teiler
int R1 = 10000;               // 10kOhm
const float Beta = 3950;      // Umrechnungsfakor des NTC
double To = 298.15;           // Temperatur in Kelvin für 25° Celsius
double Ro = 10000.0;          // Widerstand des NTC bei 25° Celsius

// <-------- End Temperature Variables -------->

// <-------- Start Display -------->

#include <Adafruit_GFX.h>

// <-------- End Display -------->

//ThingSpeak Webservice

#include <ThingSpeak.h>

#define CHANNEL_ID 2385197
#define CHANNEL_API_KEY "525R59BZS64T01I8"

WiFiClient client;

#define ErrorLED 25
#define statusLED 4
#define httpLED 2

WebServer server(80);

String phValue = "1";

void sendHtml() {
  String response = R"(
    <!DOCTYPE html>
    <html>
    <head>
        <style>
            body {
                display: flex;
                justify-content: center;
                align-items: center;
                height: 100vh;
                margin: 0;
                background-color: #ffffff; /* Change background color to white */
                font-family: sans-serif;
                font-size: 2em;
                text-align: center;
            }
            .iframe-container {
                display: flex;
                flex-direction: column;
                gap: 20px; /* Add some space between the iframes */
            }
        </style>
    </head>
    <body>
        <div class="iframe-container">
            <iframe width="450" height="260" style="border: none;" src="https://thingspeak.com/channels/2385197/widgets/774036"></iframe>
            <iframe width="450" height="260" style="border: none;" src="https://thingspeak.com/channels/2385197/charts/1?bgcolor=%23ffffff&color=%23d62020&dynamic=true&results=60&type=line&update=15"></iframe>
         </div>
    </body>
  </html>
)";

    // Den NTC-Wert lesen
    ntcValue = analogRead(ntcPin);
    // Formel zur Umrechung des Wertes
    double Vout = ntcValue * Vs/adcMax;
    double Rt = R1 * Vout / (Vs - Vout);

    double T = 1/(1/To + log(Rt/Ro)/Beta);    // Temperature in Kelvin
    phValue = T - 273.15;                          // Celsius
    
    ThingSpeak.writeField(CHANNEL_ID, 1, phValue, CHANNEL_API_KEY);

    // response.replace("PH-VALUE", phValue);
  server.send(200, "text/html", response);
}

void display_on_OLED(u8_t heap, String ph){
    display.clearDisplay();
    display.setTextSize(1);             
    display.setTextColor(WHITE);        
    display.setCursor(0,05);     
    display.println(String(heap) + "% Free memory");
    display.setCursor(0,15);
    display.println("------------");
    display.println("| PH Value |");
    display.println("------------");
    display.println("| " + String(ph) + "    |");
    display.println("------------");
    display.display();
}

void setup(void) {
  Serial.begin(115200);
  pinMode(ErrorLED, OUTPUT);
  pinMode(statusLED, OUTPUT);
  pinMode(httpLED, OUTPUT);
  digitalWrite(statusLED, HIGH);
// <-------- Start Temperature Setup -------->

  delay(1000);

// <-------- End Temperature Setup -------->

  WiFi.begin(WIFI_SSID, WIFI_PASSWORD, WIFI_CHANNEL);
  Serial.print("Connecting to WiFi ");
  Serial.print(WIFI_SSID);
  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");

  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  server.on("/", sendHtml);

  try{
  server.begin();
  Serial.println("HTTP server started (http://localhost:8180)");
  digitalWrite(httpLED, HIGH);
  throw("Server couldnt start");
  }catch(String exception){
    Serial.println(exception); 
  }
  //ThingSpeak setup
  ThingSpeak.begin(client);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
}

void loop(void) {
  server.handleClient();

  // Den NTC-Wert lesen
  ntcValue = analogRead(ntcPin);
  // Formel zur Umrechung des Wertes
  double Vout = ntcValue * Vs/adcMax;
  double Rt = R1 * Vout / (Vs - Vout);

  double T = 1/(1/To + log(Rt/Ro)/Beta);    // Temperature in Kelvin
  phValue = T - 273.15;                          // Celsius

  if(T - 273.15 >= 40){
    digitalWrite(ErrorLED, HIGH);
  }else{
    digitalWrite(ErrorLED, LOW);
  }
  uint8_t heapPercent = ESP.getFreeHeap() * 100 / ESP.getHeapSize();
  display_on_OLED(heapPercent, phValue);  
  delay(20);
}