Wokwi - Online ESP32, STM32, Arduino Simulator

// -------------------------------------------------------------
// Libraries
// -------------------------------------------------------------
#include <WiFi.h>
#include <WiFiClient.h>
#include <WebServer.h>
#include <uri/UriBraces.h>
#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"

// -------------------------------------------------------------
// Variables
// -------------------------------------------------------------
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
#define WIFI_CHANNEL 6
#define TFT_DC 2
#define TFT_CS 15
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);
WebServer server(80);

// -------------------------------------------------------------
// Structs
// -------------------------------------------------------------
struct TelemetryPoint {
  char label;
  float value;
  char unit;
  char message[256];
};

int sensorsPins[] = {32, 33, 34, 35};
int sensorsPinsCount = 4;
TelemetryPoint telemetry[4];

// -------------------------------------------------------------
// Functions
// -------------------------------------------------------------
void sendHtml() {
  String response = R"(
    <!DOCTYPE html><html>
      <head>
        <title>ESP32 Web Server Demo</title>
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <style>
          html { font-family: sans-serif; text-align: center; }
          body { display: inline-flex; flex-direction: column; }
          h1 { margin-bottom: 1.2em; } 
          h2 { margin: 0; }
          div { display: grid; grid-template-columns: 1fr 1fr; grid-template-rows: auto auto; grid-auto-flow: column; grid-gap: 1em; }
          .btn { background-color: #5B5; border: none; color: #fff; padding: 0.5em 1em;
                 font-size: 2em; text-decoration: none }
          .btn.OFF { background-color: #333; }
        </style>
      </head>
            
      <body>
        <h1>ESP32 Web Server</h1>

        <div>
          <h2>LED 1</h2>
          <a href="/toggle/1" class="btn LED1_TEXT">LED1_TEXT</a>
          <h2>LED 2</h2>
          <a href="/toggle/2" class="btn LED2_TEXT">LED2_TEXT</a>
        </div>
      </body>
    </html>
  )";
  // response.replace("LED1_TEXT", led1State ? "ON" : "OFF");
  // response.replace("LED2_TEXT", led2State ? "ON" : "OFF");
  server.send(200, "text/html", response);
}

void doReadings () {
  // Get each pin reading
  for (int thisPin = 0; thisPin < sensorsPinsCount; thisPin++) {
    float result = analogRead(sensorsPins[thisPin]);
    float voltage1 = map(result, 0, 4095, 0, 120);
    
    char message[128];
    sprintf(message, "Pin : %d, Raw Signal : %d, Mapped Signal : %.2f, 12V Signal : %.2f%s", sensorsPins[thisPin], result, voltage1, (voltage1 / 10.0), telemetry[thisPin].unit);
    
    Serial.println(message);
    telemetry[thisPin].label = 'Voltage';
    telemetry[thisPin].value = voltage1 / 10;
    telemetry[thisPin].unit = 'V';
    strcpy(telemetry[thisPin].message, message); 
  }
}

void printReadings() {
  tft.fillScreen(ILI9341_BLACK);
  tft.setCursor(0, 0);
  tft.println("IP address: " + WiFi.localIP());
  for (int thisPin = 0; thisPin < sensorsPinsCount; thisPin++) {
    tft.println(telemetry[thisPin].message);
  }
}

// -------------------------------------------------------------
// Setup
// -------------------------------------------------------------
void setup(void) {
  Serial.begin(115200);

  // SETUP OUR INPUT PINS
  for (int thisPin = 0; thisPin < sensorsPinsCount; thisPin++) {
    pinMode(sensorsPins[thisPin], INPUT);
  }

  tft.begin();
  tft.setRotation(1);

  WiFi.begin(WIFI_SSID, WIFI_PASSWORD, WIFI_CHANNEL);
  Serial.print("Connecting to WiFi ");
  Serial.print(WIFI_SSID);

  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.print("Connecting to WiFi");
  // Wait for connection

  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
    tft.print(".");
  }

  Serial.println(" Connected!");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  tft.print("\nOK! IP=");
  tft.println(WiFi.localIP());

  server.on("/", sendHtml);

  server.on(UriBraces("/toggle/{}"), []() {
    String led = server.pathArg(0);
    Serial.print("Toggle LED #");
    Serial.println(led);

    // switch (led.toInt()) {
    //   case 1:
    //     led1State = !led1State;
    //     digitalWrite(LED1, led1State);
    //     break;
    //   case 2:
    //     led2State = !led2State;
    //     digitalWrite(LED2, led2State);
    //     break;
    // }

    sendHtml();
  });

  server.begin();
  Serial.println("HTTP server started");
}

// -------------------------------------------------------------
// Main Loop
// -------------------------------------------------------------
void loop(void) {
  server.handleClient();
  doReadings();
  printReadings();
  delay(2000);
}