diff --git a/app/src/main/java/com/example/hpos/data/DataHolder.kt b/app/src/main/java/com/example/hpos/data/DataHolder.kt
index 00ef732..1406241 100644
--- a/app/src/main/java/com/example/hpos/data/DataHolder.kt
+++ b/app/src/main/java/com/example/hpos/data/DataHolder.kt
@@ -5,7 +5,8 @@ import com.example.hpos.data.model.TestRightDeviceConstants
 
 object DataHolder {
 //    var usbConnected: Boolean = false
-    val usbConnected = MutableLiveData(false)
+//    val usbConnected = MutableLiveData(false)
+    val usbConnected = MutableLiveData(true)
 
     var isStoragePermissionGranted = false
     var isAppFolderCreated = false
diff --git a/app/src/main/java/com/example/hpos/data/constant/Constants.kt b/app/src/main/java/com/example/hpos/data/constant/Constants.kt
index a21025c..dd70cb8 100644
--- a/app/src/main/java/com/example/hpos/data/constant/Constants.kt
+++ b/app/src/main/java/com/example/hpos/data/constant/Constants.kt
@@ -9,10 +9,13 @@ object Constants {
     const val TEST_RIGHT_TOTAL_PIXEL = 3694
 //    const val TEST_RIGHT_TOTAL_PIXEL = 12
 
-    const val MAXIMUM_TEST_ALLOWED_BEFORE_REFERENCE = 1
+    const val MAXIMUM_TEST_ALLOWED_BEFORE_REFERENCE = 10
 
     const val RANGE_IN_RESULT_CALCULATIONS = 10
 
     const val WAVELENGTH_OF_INTEREST_ONE = 427
     const val WAVELENGTH_OF_INTEREST_TWO = 555
+
+    const val DEVICE_PRODUCT_ID = 24597
+    const val DEVICE_VENDOR_ID = 1027
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/example/hpos/presentation/MainActivity.kt b/app/src/main/java/com/example/hpos/presentation/MainActivity.kt
index 6fb3acb..79ceba0 100644
--- a/app/src/main/java/com/example/hpos/presentation/MainActivity.kt
+++ b/app/src/main/java/com/example/hpos/presentation/MainActivity.kt
@@ -4,8 +4,10 @@ import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
+import android.hardware.usb.UsbDevice
 import android.hardware.usb.UsbManager
 import android.os.Bundle
+import android.util.Log
 import android.view.Gravity
 import android.view.Menu
 import android.widget.Toast
@@ -15,9 +17,11 @@ import androidx.core.view.get
 import androidx.lifecycle.ViewModelProvider
 import com.example.hpos.R
 import com.example.hpos.data.DataHolder
+import com.example.hpos.data.constant.Constants
 import com.example.hpos.databinding.ActivityMainBinding
 import com.example.hpos.presentation.testRight.TestRightActivity
 import com.example.hpos.util.MyViewModelFactory
+import com.hoho.android.usbserial.driver.UsbSerialProber
 
 
 class MainActivity : AppCompatActivity()
@@ -64,6 +68,21 @@ class MainActivity : AppCompatActivity()
         registerReceiver(mUsbReceiver, filter)
     }
 
+    private fun checkAndUpdateUsbConnection() {
+        val availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(getSystemService(Context.USB_SERVICE) as UsbManager)
+        if (availableDrivers.isNotEmpty() && availableDrivers[0].device.productId == Constants.DEVICE_PRODUCT_ID && availableDrivers[0].device.vendorId == Constants.DEVICE_VENDOR_ID){
+            Log.d(TAG, "Device matched -> product = ${availableDrivers[0].device.productId}, vendor = ${availableDrivers[0].device.vendorId}")
+            DataHolder.usbConnected.value = true
+        } else if (availableDrivers.isNotEmpty()) {
+            Log.d(TAG, "Device NOT matched -> product = ${availableDrivers[0].device.productId}, vendor = ${availableDrivers[0].device.vendorId}")
+            Toast.makeText(this, "Device Not Compatible", Toast.LENGTH_SHORT).show()
+            DataHolder.usbConnected.value = false
+        } else {
+            Log.d(TAG, "Device NOT Connected")
+            DataHolder.usbConnected.value = false
+        }
+    }
+
     private fun setupListeners() {
 
         binding.cvItem1.setOnClickListener {
@@ -76,11 +95,12 @@ class MainActivity : AppCompatActivity()
         }
 
         DataHolder.usbConnected.observe(this){
+//            Log.d(TAG, "usbConnected observer called with value -> $it")
             if (it){
                 myMenu?.get(0)?.icon = ContextCompat.getDrawable(this, R.drawable.ic_baseline_usb_24)
             } else {
+//                Log.d(TAG, "into no block -> $it")
                 myMenu?.get(0)?.icon = ContextCompat.getDrawable(this, R.drawable.ic_baseline_usb_off_24)
-                Toast.makeText(this, "USB NOT CONNECTED", Toast.LENGTH_SHORT).show()
             }
         }
     }
@@ -88,7 +108,7 @@ class MainActivity : AppCompatActivity()
     override fun onCreateOptionsMenu(menu: Menu?): Boolean {
         menuInflater.inflate(R.menu.my_menu, menu)
         myMenu = menu
-        DataHolder.usbConnected.value = DataHolder.usbConnected.value
+        checkAndUpdateUsbConnection()
         return true
     }
 
diff --git a/app/src/main/java/com/example/hpos/presentation/testRight/TestRightActivity.kt b/app/src/main/java/com/example/hpos/presentation/testRight/TestRightActivity.kt
index 58c2dcb..ddddda1 100644
--- a/app/src/main/java/com/example/hpos/presentation/testRight/TestRightActivity.kt
+++ b/app/src/main/java/com/example/hpos/presentation/testRight/TestRightActivity.kt
@@ -88,12 +88,13 @@ class TestRightActivity : AppCompatActivity() {
 
     private fun setupListener() {
         DataHolder.usbConnected.observe(this){
+            Log.d("USB OBSERVE", "testrightactivity called -> $it")
             if (it){
                 myMenu?.get(0)?.icon = ContextCompat.getDrawable(this, R.drawable.ic_baseline_usb_24)
             } else {
                 myMenu?.get(0)?.icon = ContextCompat.getDrawable(this, R.drawable.ic_baseline_usb_off_24)
 //                val myToast = Toast.makeText(this, "USB is Detached", Toast.LENGTH_SHORT)
-                Toast.makeText(this, "USB is Detached", Toast.LENGTH_SHORT).show()
+                Toast.makeText(this, "Device is Disconnected", Toast.LENGTH_SHORT).show()
             }
         }
     }
@@ -112,6 +113,13 @@ class TestRightActivity : AppCompatActivity() {
             onUsbError("No Device is Connected")
         } else {
             mDriver = availableDrivers[0]
+
+            if (mDriver.device.productId != Constants.DEVICE_PRODUCT_ID || mDriver.device.vendorId != Constants.DEVICE_VENDOR_ID){
+                Toast.makeText(this, "Device Connected is not supported", Toast.LENGTH_SHORT).show()
+                onBackPressed()
+                return
+            }
+
             mConnection = manager.openDevice(mDriver.device)
 
             if (mConnection == null) {