#include <WiFi.h>//library for wifi
#include <PubSubClient.h>//library for MQtt
#define LED 5
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
void callback(char* subscribetopic, byte* payload, unsigned int payloadLength);
//-------credentials of IBM Accounts------
#define ORG "by18wl"//IBM ORGANITION ID
#define DEVICE_TYPE "IOT_DEVICE"//Device type mentioned in ibm watson IOT Platform
#define DEVICE_ID "12345"//Device ID mentioned in ibm watson IOT Platform
#define TOKEN "123456789" //Token
String data3,light;
float h, t;
#define BUZZER_PIN 19 // ESP32 GIOP21 pin connected to Buzzer's pin
//-------- Customise the above values --------
char server[] = ORG ".messaging.internetofthings.ibmcloud.com";// Server Name
char publishTopic[] = "iot-2/evt/Data/fmt/json";// topic name and type of event perform and format in which data to be send
char subscribetopic[] = "iot-2/cmd/test/fmt/json";// cmd REPRESENT command type AND COMMAND IS TEST OF FORMAT STRING
char authMethod[] = "use-token-auth";// authentication method
char token[] = TOKEN;
char clientId[] = "d:" ORG ":" DEVICE_TYPE ":" DEVICE_ID;//client id
//-----------------------------------------
WiFiClient wifiClient; // creating the instance for wificlient
PubSubClient client(server, 1883, callback ,wifiClient); //calling the predefined client id by passing parameter like server id,portand wificredential
void setup()// configuring the ESP32
{
Serial.begin(115200);
Serial.begin(9600);
// dht.begin();
pinMode(LED,OUTPUT);
pinMode(BUZZER_PIN, OUTPUT);
delay(10);
lcd.init();
lcd.clear();
lcd.backlight();
Serial.println();
wificonnect();
mqttconnect();
}
void loop()// Recursive Function
{
digitalWrite(BUZZER_PIN, HIGH);
delay(1000);
if (!client.loop()) {
mqttconnect();
}
}
void mqttconnect() {
if (!client.connected()) {
Serial.print("Reconnecting client to ");
Serial.println(server);
while (!!!client.connect(clientId, authMethod, token)) {
Serial.print(".");
delay(500);
}
initManagedDevice();
Serial.println();
}
}
void wificonnect() //function defination for wificonnect
{
Serial.println();
Serial.print("Connecting to ");
WiFi.begin("Wokwi-GUEST", "", 6);//passing the wifi credentials to establish the connection
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void initManagedDevice() {
if (client.subscribe(subscribetopic)) {
Serial.println((subscribetopic));
Serial.println("subscribe to cmd OK");
} else {
Serial.println("subscribe to cmd FAILED");
}
}
void callback(char* subscribetopic, byte* payload, unsigned int payloadLength)
{
Serial.print("callback invoked for topic: ");
Serial.println(subscribetopic);
light=(char)payload[2];
Serial.println((char)payload[2]);
for (int i = 5; i < payloadLength-1; i++) {
Serial.print((char)payload[i]);
data3 += (char)payload[i];
}
// Make sure backlight is on
Serial.println("data: "+ data3);
if(light=="n")
{
digitalWrite(BUZZER_PIN, HIGH);
Serial.println(data3);
digitalWrite(LED,HIGH);
// Print a message on both lines of the LCD.
lcd.setCursor(2,0); //Set cursor to character 2 on line 0
lcd.print("It's time for");
lcd.setCursor(2,1); //Move cursor to character 2 on line 1
lcd.print(data3);
delay(5000);
digitalWrite(BUZZER_PIN, LOW);
digitalWrite(LED,LOW);
//lcd.clear();
}
else
{
digitalWrite(BUZZER_PIN, LOW);
Serial.println(data3);
digitalWrite(LED,LOW);
lcd.clear();
}
data3="";
}