diff --git a/app/src/main/java/com/example/medilightv2android/ble/BleManager.kt b/app/src/main/java/com/example/medilightv2android/ble/BleManager.kt
index 8bbd079..07090c6 100644
--- a/app/src/main/java/com/example/medilightv2android/ble/BleManager.kt
+++ b/app/src/main/java/com/example/medilightv2android/ble/BleManager.kt
@@ -613,9 +613,10 @@ class BleManager private constructor(private val context: Context) {
                         if (idx >= 0) discoveredDevices[idx] = discoveredDevices[idx].copy(isConnected = true, isConnecting = false)
                         isConnected.value = true
                         connectedDeviceName.value = try { gatt.device.name ?: "Unknown" } catch (_: Exception) { "Unknown" }
-                        // Auto-detect device preset from name
+                        // Auto-detect device preset + endian from name
                         com.example.medilightv2android.managers.PiezoHW.autoDetectPreset(connectedDeviceName.value)
-                        logd { "Device preset: ${com.example.medilightv2android.managers.PiezoHW.presetName} (from '${connectedDeviceName.value}')" }
+                        piezoCollector.forceBigEndian = connectedDeviceName.value.startsWith("VBT")
+                        logd { "Device preset: ${com.example.medilightv2android.managers.PiezoHW.presetName}, endian: ${if (piezoCollector.forceBigEndian) "BE" else "LE"} (from '${connectedDeviceName.value}')" }
 
                         lastConnectedAddress = gatt.device.address
                         reconnectAttempt = 0
diff --git a/app/src/main/java/com/example/medilightv2android/ble/PiezoPacketCollector.kt b/app/src/main/java/com/example/medilightv2android/ble/PiezoPacketCollector.kt
index 2ab6947..1678206 100644
--- a/app/src/main/java/com/example/medilightv2android/ble/PiezoPacketCollector.kt
+++ b/app/src/main/java/com/example/medilightv2android/ble/PiezoPacketCollector.kt
@@ -24,6 +24,7 @@ class PiezoPacketCollector {
     private var rawData = mutableListOf<Byte>()
     private var hasFirstPacket = false
     private var detectedBigEndian = false
+    var forceBigEndian: Boolean = true  // VBT 기기 기본 BE, 기기 연결 시 설정
 
     // Multi-channel
     var isMultiChannel: Boolean = false; private set
@@ -87,13 +88,21 @@ class PiezoPacketCollector {
         hasFirstPacket = true
         rawData.clear()
 
-        // Endian detection: first channel only → lock for remaining
-        if (currentChannel == 0 || !hasFirstPacket) {
+        // Endian detection: first channel → lock for remaining
+        // VBT 기기 = Big Endian, 2025MEDIP = Little Endian
+        // 자동 감지 fallback: 첫 샘플 기반
+        if (currentChannel == 0) {
             val b6 = bytes.getOrElse(6) { 0 }.toInt() and 0xFF
             val b7 = bytes.getOrElse(7) { 0 }.toInt() and 0xFF
             val firstSampleLE = b6 or (b7 shl 8)
             val firstSampleBE = (b6 shl 8) or b7
-            detectedBigEndian = firstSampleLE > 4095 && firstSampleBE <= 4095
+
+            detectedBigEndian = when {
+                firstSampleLE > 4095 && firstSampleBE <= 4095 -> true  // 확실히 BE
+                firstSampleBE > 4095 && firstSampleLE <= 4095 -> false // 확실히 LE
+                else -> forceBigEndian  // 둘 다 범위 내면 기기 기반 기본값 사용
+            }
+            onLog?.invoke("Endian: ${if (detectedBigEndian) "BE" else "LE"} (LE=$firstSampleLE BE=$firstSampleBE force=$forceBigEndian)")
         }
 
         // Parse repeat count