#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>
long previousMillis1 = 0; // will store last time LED
int interval1 = 500;
#define ADC_IN A5
#define ADC_REF 3.3
int LEDY = 19;
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* hostname = "broker.hivemq.com";
WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_10145291"; // yourStudentID must be unique
int PORTNUM = 1883;
void setup_wifi()
{
WiFi.begin(ssid, password);
while(WiFi.status() != WL_CONNECTED )
{
delay(1000);
Serial.print(".");
}
Serial.println();
Serial.print("Connected to ");
Serial.println(ssid);
Serial.print("Given IP by the router to ESP32 is ");
Serial.println(WiFi.localIP());
}
void callback(String topic, byte* payload, unsigned int length)
{
String messageTemp;
Serial.print("Message received in topic: ");
Serial.print(topic);
Serial.print(" length is: ");
Serial.println(length);
Serial.print("Data received from broker: ");
for (int i = 0; i<length; i++)
{
Serial.print( (char)payload[i] );
messageTemp += (char)payload[i];
}
if (topic == "room/10145291")
{
if (messageTemp == "0")
{
digitalWrite(LEDY, LOW);
}
else
{
digitalWrite(LEDY, HIGH);
}
}
}
void connectMQTT()
{
while(!client.connected() )
{
Serial.println("Connecting to MQTT ...");
if (client.connect(espClientName) ) //, mqttUser, mqttPassword) )
{
Serial.println("Connected");
MQTTSubscribe();
}
else
{
Serial.print("Failed with state ");
Serial.print(client.state() );
delay(2000);
}
}
}
void MQTTSubscribe()
{
// Subsccribe to your topics here
client.subscribe("room/10145291");
client.subscribe("Eunice/room/analog");
}
void setup_MQTT()
{
client.setServer(hostname, PORTNUM);
client.setCallback(callback);
}
void setup()
{
Serial.begin(9600);
pinMode(LEDY, OUTPUT);
setup_wifi();
setup_MQTT();
}
void loop()
{
long currentMillis = millis();
if ( currentMillis - previousMillis1 >= interval1)
{
previousMillis1 = currentMillis; // save the last time you blinked the LED
int adcRes = analogRead( A5 );
Serial.println(adcRes);
String payload = String(adcRes);
client.publish("room/10145291", payload.c_str());
}
if ( !client.connected() )
{
connectMQTT();
}
client.loop();
}