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 cae3652..6c20636 100644
--- a/app/src/main/java/com/example/medilightv2android/ble/BleManager.kt
+++ b/app/src/main/java/com/example/medilightv2android/ble/BleManager.kt
@@ -400,12 +400,8 @@ class BleManager private constructor(private val context: Context) {
     }
 
     fun sendAllChannels(mode: Int = 0): Boolean {
-        val now = System.currentTimeMillis()
-        if (now - lastMaaSentMs < 800) {
-            android.util.Log.w("BleManager", "maa THROTTLED — ${now - lastMaaSentMs}ms since last")
-            return false
-        }
-        lastMaaSentMs = now
+        if (!canSendMaa("sendAllChannels")) return false
+        lastMaaSentMs = System.currentTimeMillis()
         piezoCollector.startMultiChannel(6)
         sendRaw(CRC16.buildCommandASCII("maa", " "))
         return true
@@ -457,15 +453,34 @@ class BleManager private constructor(private val context: Context) {
         sendRaw(CRC16.buildCommandASCII("mbb", " "))
     }
 
-    /** 6채널 측정만 (maa) — 최소 800ms 간격 throttle */
+    /**
+     * 6채널 측정 명령(maa) 송신 가능 여부:
+     *  (A) 이전 응답이 아직 진행 중(isMultiChannel && !isComplete)이면 차단.
+     *      단 5초 넘게 응답이 안 오면 강제 통과(영영 deadlock 방지).
+     *  (B) 마지막 송신으로부터 1500ms 미만이면 차단(펌웨어 burst 방어).
+     */
     private var lastMaaSentMs = 0L
-    fun sendChannelsOnly(): Boolean {
+    private fun canSendMaa(caller: String): Boolean {
         val now = System.currentTimeMillis()
-        if (now - lastMaaSentMs < 800) {
-            android.util.Log.w("BleManager", "maa THROTTLED — ${now - lastMaaSentMs}ms since last")
+        val collectorBusy = piezoCollector.isMultiChannel && !piezoCollector.isComplete
+        val sinceLast = now - lastMaaSentMs
+        if (collectorBusy) {
+            if (sinceLast < 5000) {
+                android.util.Log.w("BleManager", "maa BUSY [$caller] — prev response in progress (${sinceLast}ms)")
+                return false
+            }
+            android.util.Log.w("BleManager", "maa FORCE [$caller] — prev incomplete after ${sinceLast}ms, abandoning")
+        }
+        if (sinceLast < 1500) {
+            android.util.Log.w("BleManager", "maa THROTTLED [$caller] — ${sinceLast}ms since last")
             return false
         }
-        lastMaaSentMs = now
+        return true
+    }
+
+    fun sendChannelsOnly(): Boolean {
+        if (!canSendMaa("sendChannelsOnly")) return false
+        lastMaaSentMs = System.currentTimeMillis()
         piezoCollector.startMultiChannel(6)
         sendRaw(CRC16.buildCommandASCII("maa", " "))
         return true