void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}


























package com.example.firebaseapp;

import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.database.DataSnapshot;

public class MainActivity extends AppCompatActivity {

    // Firebase Database reference
    private FirebaseDatabase mDatabase;
    private DatabaseReference mRef;

    private TextView textView;  // TextView to display data

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Initialize Firebase
        mDatabase = FirebaseDatabase.getInstance();
        mRef = mDatabase.getReference("test");  // The "test" node from your Firebase Realtime Database

        textView = findViewById(R.id.textView);  // Linking the TextView from XML

        // Read data from Firebase Realtime Database
        mRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                // Get the data from Firebase
                String ledStatus = dataSnapshot.child("LED").getValue(String.class);  // Get LED status
                String intData = dataSnapshot.child("int").getValue(String.class);  // Get int data
                String floatData = dataSnapshot.child("float").getValue(String.class);  // Get float data

                // Display the data in the TextView
                String displayText = "LED Status: " + ledStatus + "\nInt: " + intData + "\nFloat: " + floatData;
                textView.setText(displayText);
            }

            @Override
            public void onCancelled(com.google.firebase.database.DatabaseError databaseError) {
                // If there's an error in retrieving the data
                Toast.makeText(MainActivity.this, "Failed to read value.", Toast.LENGTH_SHORT).show();
            }
        });
    }
}