Wokwi - Online ESP32, STM32, Arduino Simulator

/**#include <WiFi.h>
#include <WebServer.h>
#include <ESP32Servo.h>
#include <LiquidCrystal.h>

// LCD
LiquidCrystal lcd(23, 22, 21, 19, 18, 5);

// Servo
Servo servoEntry;
Servo servoExit;
#define SERVO_ENTRY_PIN 15
#define SERVO_EXIT_PIN 4

// Ultrasonic Pins
#define TRIG_P1 13
#define ECHO_P1 34
#define TRIG_P2 14
#define ECHO_P2 35
#define TRIG_P3 27
#define ECHO_P3 33
#define TRIG_ENTRY 26
#define ECHO_ENTRY 32
#define TRIG_EXIT 25
#define ECHO_EXIT 12

// Threshold values
#define PARKING_THRESHOLD 30   // cm, for slot sensors
#define ENTRY_THRESHOLD   20   // cm, for entry gate
#define EXIT_THRESHOLD    20   // cm, for exit gate
#define SERVO_OPEN 90
#define SERVO_CLOSED 0

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// WebServer
WebServer server(80);

// Variables
int freeSlots = 0;
long entryDist = 0;
long exitDist = 0;
bool slot1Free = true, slot2Free = true, slot3Free = true;

// Function to read ultrasonic distance
long readUltrasonicCM(int trigPin, int echoPin) {
  digitalWrite(trigPin, LOW); delayMicroseconds(2);
  digitalWrite(trigPin, HIGH); delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH, 30000);
  return duration * 0.034 / 2;
}

// Serve HTML page
void handleRoot() {
  String html = "<!DOCTYPE html><html><head><title>Parking System</title>"
                "<meta http-equiv='refresh' content='1'>"
                "<style>"
                "body{font-family:Arial;text-align:center;background:#f4f4f9;}"
                ".slot{font-size:20px;margin:10px;padding:10px;border-radius:8px;display:inline-block;width:150px;}"
                ".free{background:#8fbc8f;color:white;}"
                ".occupied{background:#cd5c5c;color:white;}"
                "</style></head><body>";

  html += "<h1>🚗 Smart Car Parking 🚗</h1>";
  html += "<p><b>Free Slots: " + String(freeSlots) + "</b></p>";

  html += "<div class='slot " + String(slot1Free ? "free" : "occupied") + "'>Slot 1: " + String(slot1Free ? "Free" : "Occupied") + "</div>";
  html += "<div class='slot " + String(slot2Free ? "free" : "occupied") + "'>Slot 2: " + String(slot2Free ? "Free" : "Occupied") + "</div>";
  html += "<div class='slot " + String(slot3Free ? "free" : "occupied") + "'>Slot 3: " + String(slot3Free ? "Free" : "Occupied") + "</div>";

  html += "<p>Entry Gate: " + String(entryDist < ENTRY_THRESHOLD ? "Open" : "Closed") + "</p>";
  html += "<p>Exit Gate: " + String(exitDist < EXIT_THRESHOLD ? "Open" : "Closed") + "</p>";

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

void setup() {
  Serial.begin(115200);

  // LCD init
  lcd.begin(16, 2);
  lcd.print("Smart Parking");

  // Servo init
  servoEntry.attach(SERVO_ENTRY_PIN);
  servoExit.attach(SERVO_EXIT_PIN);
  servoEntry.write(SERVO_CLOSED);
  servoExit.write(SERVO_CLOSED);

  // Ultrasonic pins
  pinMode(TRIG_P1, OUTPUT); pinMode(ECHO_P1, INPUT);
  pinMode(TRIG_P2, OUTPUT); pinMode(ECHO_P2, INPUT);
  pinMode(TRIG_P3, OUTPUT); pinMode(ECHO_P3, INPUT);
  pinMode(TRIG_ENTRY, OUTPUT); pinMode(ECHO_ENTRY, INPUT);
  pinMode(TRIG_EXIT, OUTPUT); pinMode(ECHO_EXIT, INPUT);

  // Connect WiFi
  lcd.setCursor(0,1); lcd.print("Connecting WiFi...");
  WiFi.begin(ssid, password);
  while(WiFi.status() != WL_CONNECTED) {
    delay(500); Serial.print(".");
  }
  Serial.println("WiFi connected! IP:");
  Serial.println(WiFi.localIP());
  lcd.clear(); lcd.print("WiFi Connected");

  // Start server
  server.on("/", handleRoot);
  server.begin();
}

void loop() {
  // Read parking slots
  long d1 = readUltrasonicCM(TRIG_P1, ECHO_P1);
  long d2 = readUltrasonicCM(TRIG_P2, ECHO_P2);
  long d3 = readUltrasonicCM(TRIG_P3, ECHO_P3);

  slot1Free = (d1 > PARKING_THRESHOLD);
  slot2Free = (d2 > PARKING_THRESHOLD);
  slot3Free = (d3 > PARKING_THRESHOLD);

  freeSlots = (slot1Free ? 1 : 0) + (slot2Free ? 1 : 0) + (slot3Free ? 1 : 0);

  // Entry & Exit
  entryDist = readUltrasonicCM(TRIG_ENTRY, ECHO_ENTRY);
  exitDist  = readUltrasonicCM(TRIG_EXIT, ECHO_EXIT);

  // Gate control
  if(entryDist < ENTRY_THRESHOLD && freeSlots > 0) servoEntry.write(SERVO_OPEN);
  else servoEntry.write(SERVO_CLOSED);

  if(exitDist < EXIT_THRESHOLD) servoExit.write(SERVO_OPEN);
  else servoExit.write(SERVO_CLOSED);

  // LCD update
  lcd.clear(); 
lcd.setCursor(0,0);
lcd.print("P1:");
lcd.print(slot1Free ? "F" : "O");
lcd.print(" P2:");
lcd.print(slot2Free ? "F" : "O");
lcd.print(" P3:");
lcd.print(slot3Free ? "F" : "O");

lcd.setCursor(0,1);
lcd.print("E:");
lcd.print(entryDist < ENTRY_THRESHOLD ? "Open" : "Clsd");
lcd.print(" X:");
lcd.print(exitDist < EXIT_THRESHOLD ? "Open" : "Clsd");


  // Handle web server
  server.handleClient();

  delay(1000);
}
**/



































#include <WiFi.h>
#include <HTTPClient.h>
#include <ESP32Servo.h>
#include <LiquidCrystal.h>
#include <WebServer.h>

// LCD
LiquidCrystal lcd(23, 22, 21, 19, 18, 5);

// Servo
Servo servoEntry;
Servo servoExit;
#define SERVO_ENTRY_PIN 15
#define SERVO_EXIT_PIN 4

// Ultrasonic Pins
#define TRIG_P1 13
#define ECHO_P1 34
#define TRIG_P2 14
#define ECHO_P2 35
#define TRIG_P3 27
#define ECHO_P3 33
#define TRIG_ENTRY 26
#define ECHO_ENTRY 32
#define TRIG_EXIT 25
#define ECHO_EXIT 12

// Threshold values
#define PARKING_THRESHOLD 30
#define ENTRY_THRESHOLD   20
#define EXIT_THRESHOLD    20
#define SERVO_OPEN 90
#define SERVO_CLOSED 0

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ThingSpeak API key
String apiKey = "L1VBBD49FRDZDYMS";   // 🔹 your key here

// Variables
int freeSlots = 0;
long entryDist = 0;
long exitDist = 0;
bool slot1Free = true, slot2Free = true, slot3Free = true;

// Web server
WebServer server(80);

long readUltrasonicCM(int trigPin, int echoPin) {
  digitalWrite(trigPin, LOW); delayMicroseconds(2);
  digitalWrite(trigPin, HIGH); delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH, 30000);
  return duration * 0.034 / 2;
}

// Web page content
String generateHTML() {
  String html = "<html><head><title>Smart Parking</title>";
  html += "<style>body{font-family:Arial;text-align:center;} table{margin:auto;border-collapse:collapse;} td,th{border:1px solid #444;padding:10px;}</style></head><body>";
  html += "<h2>🚗 Smart Parking System</h2>";
  html += "<table><tr><th>Slot</th><th>Status</th></tr>";
  html += "<tr><td>P1</td><td>" + String(slot1Free ? "Free" : "Occupied") + "</td></tr>";
  html += "<tr><td>P2</td><td>" + String(slot2Free ? "Free" : "Occupied") + "</td></tr>";
  html += "<tr><td>P3</td><td>" + String(slot3Free ? "Free" : "Occupied") + "</td></tr>";
  html += "</table><br>";
  html += "<h3>Free Slots: " + String(freeSlots) + "</h3>";
  html += "<p>Entry Gate: " + String(entryDist < ENTRY_THRESHOLD ? "Open" : "Closed") + "</p>";
  html += "<p>Exit Gate: " + String(exitDist < EXIT_THRESHOLD ? "Open" : "Closed") + "</p>";
  html += "</body></html>";
  return html;
}

void handleRoot() {
  server.send(200, "text/html", generateHTML());
}

void setup() {
  Serial.begin(115200);

  // LCD init
  lcd.begin(16, 2);
  lcd.print("Smart Parking");

  // Servo init
  servoEntry.attach(SERVO_ENTRY_PIN);
  servoExit.attach(SERVO_EXIT_PIN);
  servoEntry.write(SERVO_CLOSED);
  servoExit.write(SERVO_CLOSED);

  // Ultrasonic pins
  pinMode(TRIG_P1, OUTPUT); pinMode(ECHO_P1, INPUT);
  pinMode(TRIG_P2, OUTPUT); pinMode(ECHO_P2, INPUT);
  pinMode(TRIG_P3, OUTPUT); pinMode(ECHO_P3, INPUT);
  pinMode(TRIG_ENTRY, OUTPUT); pinMode(ECHO_ENTRY, INPUT);
  pinMode(TRIG_EXIT, OUTPUT); pinMode(ECHO_EXIT, INPUT);

  // WiFi connect
  lcd.setCursor(0,1); lcd.print("Connecting WiFi...");
  WiFi.begin(ssid, password);
  while(WiFi.status() != WL_CONNECTED) {
    delay(500); Serial.print(".");
  }
  Serial.println("WiFi connected! IP:");
  Serial.println(WiFi.localIP());
  lcd.clear(); lcd.print("WiFi Connected");

  // Web server routes
  server.on("/", handleRoot);
  server.begin();
}

void loop() {
  // Read slots
  long d1 = readUltrasonicCM(TRIG_P1, ECHO_P1);
  long d2 = readUltrasonicCM(TRIG_P2, ECHO_P2);
  long d3 = readUltrasonicCM(TRIG_P3, ECHO_P3);

  slot1Free = (d1 > PARKING_THRESHOLD);
  slot2Free = (d2 > PARKING_THRESHOLD);
  slot3Free = (d3 > PARKING_THRESHOLD);
  freeSlots = (slot1Free ? 1 : 0) + (slot2Free ? 1 : 0) + (slot3Free ? 1 : 0);

  // Entry & Exit
  entryDist = readUltrasonicCM(TRIG_ENTRY, ECHO_ENTRY);
  exitDist  = readUltrasonicCM(TRIG_EXIT, ECHO_EXIT);

  // Gate control
  if(entryDist < ENTRY_THRESHOLD && freeSlots > 0) servoEntry.write(SERVO_OPEN);
  else servoEntry.write(SERVO_CLOSED);

  if(exitDist < EXIT_THRESHOLD) servoExit.write(SERVO_OPEN);
  else servoExit.write(SERVO_CLOSED);

  // LCD update
  lcd.clear(); 
  lcd.setCursor(0,0);
  lcd.print("P1:");
  lcd.print(slot1Free ? "F" : "O");
  lcd.print(" P2:");
  lcd.print(slot2Free ? "F" : "O");
  lcd.print(" P3:");
  lcd.print(slot3Free ? "F" : "O");

  lcd.setCursor(0,1);
  lcd.print("E:");  
  lcd.print(entryDist < ENTRY_THRESHOLD ? "Open" : "Clsd");
  lcd.print(" X:");
  lcd.print(exitDist < EXIT_THRESHOLD ? "Open" : "Clsd");

  // Send to ThingSpeak
  if(WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = "http://api.thingspeak.com/update?api_key=" + apiKey +
                 "&field1=" + String(slot1Free ? 1 : 0) +
                 "&field2=" + String(slot2Free ? 1 : 0) +
                 "&field3=" + String(slot3Free ? 1 : 0) +
                 "&field4=" + String(entryDist < ENTRY_THRESHOLD ? 1 : 0) +
                 "&field5=" + String(exitDist < EXIT_THRESHOLD ? 1 : 0) +
                 "&field6=" + String(freeSlots);

    http.begin(url);
    int httpCode = http.GET();
    if(httpCode > 0) {
      Serial.println("Data sent: " + url);
    } else {
      Serial.println("Error sending data");
    }
    http.end();
  }

  // Handle web requests
  server.handleClient();

  delay(2000);  // refresh rate
}