#include "WiFi.h"
#include <PubSubClient.h>
#include "DHT.h"
#include <ArduinoJson.h>
DynamicJsonDocument doc(1024);
#define DHTPIN 14
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqttServer = "broker.hivemq.com";
int port = 1883;
char clientId[50];
WiFiClient espClient;
PubSubClient client(espClient);
byte analog_pin = 12;
const int triggerPin = 4;
const int echoPin = 25;
String sensorData;
byte led_pin=19;
byte buzzer_pin=27;
String ledValue;
String buzzerValue;
void setup()
{
// put your setup code here, to run once:
Serial.begin(115200);
Serial.println("Hello, ESP32!");
pinMode(triggerPin, OUTPUT);
pinMode(echoPin, INPUT_PULLUP);
pinMode(led_pin, OUTPUT);
pinMode(buzzer_pin, OUTPUT);
Serial.print("Connecting to ");
Serial.println(ssid);
wifiConnect();
client.setServer(mqttServer, port);
client.setCallback(callback);
dht.begin();
}
void loop()
{
digitalWrite(triggerPin, LOW);
delayMicroseconds(2);
digitalWrite(triggerPin, HIGH);
delayMicroseconds(10);
digitalWrite(triggerPin, LOW);
float duration = pulseIn(echoPin, HIGH);
float distance = duration * 0.034 / 2;
Serial.println("Distance: " + String(distance, 0) + " cm");
Serial.println("Distance: " + String(distance / 30.48) + " feet");
// float distance_in_cm =float(distance,0);
float distance_in_feet = float(distance / 30.48);
// doc["temperature"]=temperature;
Serial.println(distance);
int analogstatus = analogRead(analog_pin);
Serial.println(analogstatus);
float humidity = dht.readHumidity();
Serial.println(humidity);
float temperature = dht.readTemperature();
Serial.println(temperature);
doc["Temperature"] = temperature;
doc["humidity"] = humidity;
doc["analogstatus"] = analogstatus;
doc["distance_in_cm"] = String(distance, 0);
doc["distance_in_feet"] = distance_in_feet;
doc.remove("led_value");
doc.remove("buzzer_value");
serializeJson(doc, sensorData);
Serial.println(sensorData);
if (!client.connected())
{
mqttReconnect();
}
else
{
client.publish("esp32-pub2", sensorData.c_str());
}
client.loop();
// put delay(1000); // this speeds up the simulation
delay(1000);
}
void mqttReconnect()
{
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
long r = random(1000);
sprintf(clientId, "fcs-clientId-%ld", r);
if (client.connect(clientId)) {
Serial.print(clientId);
Serial.println(" connected");
client.subscribe("ESP32-data2");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}
void callback(char* topic, byte* message, unsigned int length){
Serial.print("Message arrived on topic: ");
Serial.print(topic);
Serial.print(". Message: ");
String stMessage;
for (int i = 0; i < length; i++) {
// Serial.print((char)message[i]);
stMessage += (char)message[i];
}
Serial.println(stMessage);
DeserializationError error = deserializeJson(doc,stMessage);
if (error)
{
Serial.print("Parsing failed: ");
Serial.println(error.c_str());
return;
}
else{
Serial.println("no error...");
}
ledValue=doc["led_value"].as<String>();
buzzerValue=doc["buzzer_value"].as<String>();
Serial.println(ledValue);
Serial.println(buzzerValue);
if(ledValue=="led_on")
{
digitalWrite(led_pin, HIGH);
}
if(buzzerValue=="buzzer_on")
{
digitalWrite(buzzer_pin, HIGH);
}
else if(ledValue="led_off")
{
digitalWrite(led_pin, LOW);
}
else if(buzzerValue="buzzer_off")
{
digitalWrite(buzzer_pin, LOW);
}
}
void wifiConnect()
{
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
}