#include <ESP8266WiFi.h>
#include <MQTT.h>

const char ssid[] = "Wokwi-Gues";
const char pass[] = "";

WiFiClientSecure net;
MQTTClient client;

unsigned long lastMillis = 0;

void connect() {
  Serial.print("checking wifi...");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(1000);
  }

  // do not verify tls certificate
  // check the following example for methods to verify the server:
  // https://github.com/esp8266/Arduino/blob/master/libraries/ESP8266WiFi/examples/BearSSL_Validation/BearSSL_Validation.ino
  net.setInsecure();

  Serial.print("\nconnecting...");
  while (!client.connect("arduino", "public", "public")) {
    Serial.print(".");
    delay(1000);
  }

  Serial.println("\nconnected!");

  client.subscribe("esp/hcsr04");
  // client.unsubscribe("/hello");
}

void messageReceived(String &topic, String &payload) {
  Serial.println("incoming: " + topic + " - " + payload);

  // Note: Do not use the client in the callback to publish, subscribe or
  // unsubscribe as it may cause deadlocks when other things arrive while
  // sending and receiving acknowledgments. Instead, change a global variable,
  // or push to a queue and handle it in the loop after calling `client.loop()`.
}

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, pass);

  // Note: Local domain names (e.g. "Computer.local" on OSX) are not supported
  // by Arduino. You need to set the IP address directly.
  //
  // MQTT brokers usually use port 8883 for secure connections.
  client.begin("broker.emqx.i", 8883, net);
  client.onMessage(messageReceived);

  connect();
}

void loop() {
  client.loop();
  delay(10);  // <- fixes some issues with WiFi stability

  if (!client.connected()) {
    connect();
  }

  // publish a message roughly every second.
  if (millis() - lastMillis > 1000) {
    lastMillis = millis();
    client.publish("esp/hcsr0", "distanceCm");
  }
}















#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

int lcdColumns = 16;
int lcdRows = 2;

const int trigPin = 14;
const int echoPin = 12;
const int buzzerPin = 13;

int vs = D0;
int sensorGetar = 0;
int distance = 0;

//define sound velocity in cm/uS
#define SOUND_VELOCITY 0.034


long duration;
float distanceCm;

LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows); 

const char* ssid = "Wokwi-Gues";
const char* password = "";
const char* mqtt_server = "broker.emqx.io";

WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE  (50)
char msg[MSG_BUFFER_SIZE];
int value = 0;
int lastData;

void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

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

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print("esp/hcsr04");
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  // Switch on the LED if an 1 was received as first character
  if ((char)payload[0] == '1') {
    digitalWrite(BUILTIN_LED, LOW);   // Turn the LED on (Note that LOW is the voltage level
    // but actually the LED is on; this is because
    // it is active low on the ESP-01)
  } else {
    digitalWrite(BUILTIN_LED, HIGH);  // Turn the LED off by making the voltage HIGH
  }

}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "mqttjs_";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("esp/hcsr04", "distanceCm");
      client.publish("esp/sw420", "sensorGetar");
      // ... and resubscribe
      client.subscribe("esp/hcsr04");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200); // Starts the serial communication
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  pinMode(buzzerPin, OUTPUT);
  pinMode(vs, INPUT);
  lcd.init();
  // turn on LCD backlight                      
  lcd.backlight();

  pinMode(BUILTIN_LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {
  digitalWrite(buzzerPin, LOW);
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);

  distanceCm = duration * 0.034/2;
  
  // Calculate the distance
if (distanceCm < 100){
  Serial.print("distance(Cm): ");
  Serial.println(distanceCm);
  digitalWrite(buzzerPin, HIGH);
  delay(200);
  digitalWrite(buzzerPin, LOW);
  delay(100);
  digitalWrite(buzzerPin, HIGH);
  delay(200);
  digitalWrite(buzzerPin, LOW);
  delay(100);
 }

if (!client.connected()) {
    reconnect();
  }
  client.loop();
  value = distanceCm;
 

  unsigned long now = millis();
  if (now - lastMsg > 2000) {
    lastMsg = now;
    ++value;
  if(!lastData == value){
    lastData = value;
    sprintf(msg,"%f", value);
    Serial.print("Publish message: ");
    Serial.println(distanceCm);
    client.publish("esp/hcsr04", msg);
  }
  }
 lcd.setCursor(0,1);
 sensorGetar = digitalRead(vs);
 Serial.print("sensorGetar");
 Serial.println("sensorGetar");
 if(sensorGetar == 1){
  lcd.print("PEOPLE DECTECTED");
  delay(1000);
  lcd.clear();
 }else if (sensorGetar == 0){
  lcd.print("IOT SMART SECURITY");
  delay(1000);
  lcd.clear();
  }
 }