Wokwi - Online ESP32, STM32, Arduino Simulator

#include <WiFi.h>
#include <WebServer.h>
#include "DHTesp.h"

// Wi-Fi (replace with your SSID/PASS)
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Pins
#define DHT_PIN 15
#define SOIL_PIN 34
#define RELAY_PIN 17
#define TRIG_PIN 26
#define ECHO_PIN 27

DHTesp dht;
WebServer server(80);

// Modes & states
bool autoMode = true;
bool pumpOn = false;
int currentCrop = 0;

// Crop database
struct Crop { const char* name; int minMoisture; };
Crop crops[] = {
  {"Potato", 45},
  {"Tomato", 40},
  {"Maize", 35}
};

// Relay control
void pumpControl(bool state) {
  pumpOn = state;
  digitalWrite(RELAY_PIN, state ? LOW : HIGH); // active low relay
}

// Calculate soil % (use calibration in real hardware)
int getSoilMoisture() {
  int raw = analogRead(SOIL_PIN);
  int dry = 3000, wet = 1100;
  int percent = map(raw, dry, wet, 0, 100);
  if (percent < 0) percent = 0;
  if (percent > 100) percent = 100;
  return percent;
}

// Tank level (mock in Wokwi, works with ultrasonic)
int getTankLevel() {
  digitalWrite(TRIG_PIN, LOW); delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH); delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH, 30000);
  float dist = duration / 58.0; // cm
  float tankHeight = 100.0;     // adjust to real tank
  float pct = (1.0 - (dist / tankHeight)) * 100.0;
  if (pct < 0) pct = 0;
  if (pct > 100) pct = 100;
  return (int)pct;
}

// Web page
void handleRoot() {
  int soil = getSoilMoisture();
  float temp = dht.getTemperature();
  float hum = dht.getHumidity();
  int tank = getTankLevel();

  String html = "<html><head><meta name='viewport' content='width=device-width, initial-scale=1'>";
  html += "<style>body{font-family:sans-serif;} button{padding:10px;margin:5px;}</style></head><body>";
  html += "<h2>🌱 AgroSmart Dashboard</h2>";
  html += "<p><b>Temperature:</b> " + String(temp) + " °C</p>";
  html += "<p><b>Humidity:</b> " + String(hum) + " %</p>";
  html += "<p><b>Soil Moisture:</b> " + String(soil) + " %</p>";
  html += "<p><b>Tank Level:</b> " + String(tank) + " %</p>";
  html += "<p><b>Mode:</b> " + String(autoMode ? "AUTO" : "MANUAL") + "</p>";
  html += "<p><b>Pump:</b> " + String(pumpOn ? "ON" : "OFF") + "</p><hr>";

  // Crop selector
  html += "<form action='/setcrop'>";
  html += "Crop: <select name='c'>";
  for (int i=0;i<3;i++) {
    html += "<option value='" + String(i) + "'";
    if (i == currentCrop) html += " selected";
    html += ">" + String(crops[i].name) + "</option>";
  }
  html += "</select><input type='submit' value='Set'></form><br>";

  // Buttons
  html += "<a href='/toggle'><button>Toggle Auto/Manual</button></a>";
  html += "<a href='/pump?on=1'><button>Pump ON</button></a>";
  html += "<a href='/pump?on=0'><button>Pump OFF</button></a>";

  html += "</body></html>";
  server.send(200, "text/html", html);
}

void handleSetCrop() {
  if (server.hasArg("c")) {
    currentCrop = server.arg("c").toInt();
  }
  server.sendHeader("Location", "/");
  server.send(302, "text/plain", "");
}

void handleToggle() {
  autoMode = !autoMode;
  server.sendHeader("Location", "/");
  server.send(302, "text/plain", "");
}

void handlePump() {
  if (server.hasArg("on")) {
    pumpControl(server.arg("on") == "1");
  }
  server.sendHeader("Location", "/");
  server.send(302, "text/plain", "");
}

void setup() {
  Serial.begin(115200);
  dht.setup(DHT_PIN, DHTesp::DHT22);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pumpControl(false);

  WiFi.begin(ssid, password);
  Serial.print("Connecting WiFi");
  while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); }
  Serial.println(" Connected! IP=" + WiFi.localIP().toString());

  server.on("/", handleRoot);
  server.on("/setcrop", handleSetCrop);
  server.on("/toggle", handleToggle);
  server.on("/pump", handlePump);
  server.begin();
}

void loop() {
  server.handleClient();

  if (autoMode) {
    int soil = getSoilMoisture();
    int tank = getTankLevel();
    if (soil < crops[currentCrop].minMoisture && tank > 10) {
      pumpControl(true);
    } else {
      pumpControl(false);
    }
  }
}