1. Load에서 편집 기능 사용 시 Repetition 변경할 경우 앱이 튕기는 증상 수정

2. Pulse Duration 및 Fluence 변경 할 경우 Repetition 제한되는 값이 최대 범위를 벗어날 경우, 변경된 Pulse Duration 및 Fluence에 맞게 최대값으로 설정되도록 수정

README.md

@@ -214,3 +214,10 @@
   - `loadFluenceTable()`, `loadHzTable()`, `calculateInterpolatedC()` 영향 확인
 - 성능/안정성 이슈 시
   - `txPacketLoop()` 주기, `RX_TIMEOUT_THRESHOLD`, DB 로그 적재량 점검
+
+## 10) Troubleshooting
+
+- 시리얼 초기 TX 누락(Startup race, FD 설명, 수정 내역):
+  - [`docs/serial_tx_startup_race.md`](docs/serial_tx_startup_race.md)
+- 변경 요약 문서(`git diff` 기준):
+  - [`docs/change_summary_2026-03-04.md`](docs/change_summary_2026-03-04.md)

app/src/main/java/com/laseroptek/raman/const/HzTable_10_10.kt

@@ -9,7 +9,7 @@ package com.laseroptek.raman.const
 
 val HzTable_10_10 = mapOf(
     // Pulse Width = 0.5f
-    Pair(0.5f, 0.5f) to KEY_BLUE,
+    Pair(0.5f, 0.5f) to KEY_GREEN,
     Pair(0.5f, 0.6f) to KEY_BLUE,
     Pair(0.5f, 0.7f) to KEY_BLUE,
     Pair(0.5f, 0.8f) to KEY_BLUE,

app/src/main/java/com/laseroptek/raman/const/HzTable_5_5.kt

@@ -24,7 +24,7 @@ val HzTable_5_5 = mapOf(
     Pair(0.5f,3.4f) to KEY_BLUE,
     Pair(0.5f,3.6f) to KEY_BLUE,
     Pair(0.5f,3.8f) to KEY_BLUE,
-    Pair(0.5f,4.0f) to KEY_YELLOW,
+    Pair(0.5f,4.0f) to KEY_BLUE,
     Pair(0.5f,4.2f) to KEY_YELLOW,
     Pair(0.5f,4.4f) to KEY_YELLOW,
     Pair(0.5f,4.6f) to KEY_YELLOW,

app/src/main/java/com/laseroptek/raman/const/HzTable_7_7.kt

@@ -108,7 +108,7 @@ val HzTable_7_7 = mapOf(
     Pair(1.5f, 8.0f) to KEY_GRAY,
 
     // Pulse Width = 3f
-    Pair(3f, 1.1f) to KEY_RED,
+    Pair(3f, 1.1f) to KEY_GRAY,
     Pair(3f, 1.2f) to KEY_GRAY,
     Pair(3f, 1.3f) to KEY_GRAY,
     Pair(3f, 1.4f) to KEY_GRAY,

app/src/main/java/com/laseroptek/raman/const/Pallas3Const.kt

@@ -61,7 +61,7 @@ const val MAX_Q_SWITCH_VALUE = 250.0f
 const val MAX_REFER1_VALUE = 99999999   // 8 byte ascii (ENERGY DETECT MEASURED VALUE)
 const val DEFAULT_REFER1_VALUE = 0      // initial state
 
-const val DEFAULT_DCD_GAS_PRESSURE = 06.5f
+const val DEFAULT_DCD_GAS_PRESSURE = 08.0f
 const val DEFAULT_SPAY_DCD_TIME = 10
 const val DEFAULT_SPAY_DCD_DELAY = 10
 
@@ -461,17 +461,17 @@ val dcdLifeSpanAdjustLists = listOf( 0.5f, 0.7f, 0.9f, 1.0f, 1.1f, 1.2f )
 val dcdLifeSpanAdjustStringLists = dcdLifeSpanAdjustLists.map{ it.toString() }
 
 val dcdSprayValues = listOf(10, 20, 30, 40, 50, 60, 70, 80, 90, 100).map{ it.toString() }
-val dcdDelayValues = listOf(10, 20, 30, 40, 50, 60, 70, 80, 90, 100).map{ it.toString() }
+val dcdDelayValues = listOf(10, 20, 30, 40).map{ it.toString() }
 
 // default spray dcd list for options
 val SprayDcdList = listOf<SprayDcd>(
-    SprayDcd(status = 0x44, sprayTime = 10, sprayDelay = 10), // default
-    SprayDcd(status = 0x44, sprayTime = 10, sprayDelay = 10),
-    SprayDcd(status = 0x44, sprayTime = 20, sprayDelay = 20),
-    SprayDcd(status = 0x44, sprayTime = 30, sprayDelay = 20),
-    SprayDcd(status = 0x44, sprayTime = 40, sprayDelay = 40),
-    SprayDcd(status = 0x44, sprayTime = 50, sprayDelay = 50),
-    SprayDcd(status = 0x44, sprayTime = 60, sprayDelay = 60),
+    SprayDcd(status = 0x41, sprayTime = 10, sprayDelay = 10), // default
+    SprayDcd(status = 0x41, sprayTime = 10, sprayDelay = 10),
+    SprayDcd(status = 0x41, sprayTime = 20, sprayDelay = 10),
+    SprayDcd(status = 0x41, sprayTime = 30, sprayDelay = 20),
+    SprayDcd(status = 0x41, sprayTime = 40, sprayDelay = 20),
+    SprayDcd(status = 0x41, sprayTime = 50, sprayDelay = 30),
+    SprayDcd(status = 0x41, sprayTime = 60, sprayDelay = 30),
 )
 
 val PresetList = listOf<Preset>(

app/src/main/java/com/laseroptek/raman/data/model/serial/DcdGas.kt

@@ -3,7 +3,7 @@ package com.laseroptek.raman.data.model.serial
 import com.laseroptek.raman.const.DEFAULT_DCD_GAS_PRESSURE
 
 data class DcdGas(
-    val status: Int = 0x41,     // 1Byte(A(0x41): on, D(0x44): off, P(0x50): pressure)
+    val status: Int = 0x50,     // 1Byte(A(0x41): on, D(0x44): off, P(0x50): pressure)
     val pressure: Float = DEFAULT_DCD_GAS_PRESSURE,   // Ascii 4Byte (xx.x): Pressure
     val ok: Int = 0x00,     // 1Byte(N(0x4E): Not OK, O(0x00F): OK)/
 )

app/src/main/java/com/laseroptek/raman/data/model/serial/HandPiece.kt

@@ -1,5 +1,5 @@
 package com.laseroptek.raman.data.model.serial
 
 data class HandPiece(
-    val type:Int = 1  // ascii (00 ~ 99)
+    val type:Int = 0  // ascii (00 ~ 99)
 )

app/src/main/java/com/laseroptek/raman/data/source/preference/Preference.kt

@@ -88,4 +88,7 @@ interface Preference {
     suspend fun getPowerSupplySerialListFromPreference(): Flow<List<String>>
     /////
 
-}
+    suspend fun saveInfoChartLineStates(states: Map<String, Boolean>)
+    suspend fun getInfoChartLineStates(): Flow<Map<String, Boolean>>
+
+}

app/src/main/java/com/laseroptek/raman/repository/PreferenceRepository.kt

@@ -68,6 +68,9 @@ class PreferenceRepository(private val context: Context) : Preference {
         val PRODUCT_SERIAL = stringPreferencesKey("PRODUCT_SERIAL")
         val LASER_HAND_SERIAL = stringPreferencesKey("LASER_HAND_SERIAL")
         val POWER_SUPPLY_SERIAL = stringPreferencesKey("POWER_SUPPLY_SERIAL")
+
+        // InfoScreen Chart Checkboxes
+        val INFO_CHART_LINE_STATES = stringPreferencesKey("INFO_CHART_LINE_STATES")
     }
 
     override suspend fun clearAllPreferences() {
@@ -559,4 +562,31 @@ class PreferenceRepository(private val context: Context) : Preference {
             emit(listOf("B", "U", "O", "C", "L", "D"))
         }
     }
-}
+
+    override suspend fun saveInfoChartLineStates(states: Map<String, Boolean>) {
+        try {
+            val stateJson = gson.toJson(states)
+            context.datastore.edit { preferences ->
+                preferences[INFO_CHART_LINE_STATES] = stateJson
+            }
+        } catch (e: Exception) {
+            Timber.e(e, "Failed to serialize INFO_CHART_LINE_STATES to JSON.")
+        }
+    }
+
+    override suspend fun getInfoChartLineStates(): Flow<Map<String, Boolean>> {
+        return context.datastore.data.map { preferences ->
+            preferences[INFO_CHART_LINE_STATES]
+        }.distinctUntilChanged().map { jsonString ->
+            if (!jsonString.isNullOrBlank()) {
+                val type = object : TypeToken<Map<String, Boolean>>() {}.type
+                gson.fromJson<Map<String, Boolean>>(jsonString, type) ?: emptyMap()
+            } else {
+                emptyMap()
+            }
+        }.catch { e ->
+            Timber.e(e, "Failed to get or parse INFO_CHART_LINE_STATES. Emitting default.")
+            emit(emptyMap())
+        }
+    }
+}

app/src/main/java/com/laseroptek/raman/ui/MainActivity.kt

@@ -260,9 +260,11 @@ class MainActivity : ComponentActivity() {
                     // This prevents serial interrupts from stealing CPU during the first frame.
                     delay(200)
 
-                    vm.txPacketOnce()
-
+                    // IMPORTANT:
+                    // rxPacketLoop() starts serial open() asynchronously.
+                    // Start RX first so txPacketOnce() is less likely to run before FD is ready.
                     vm.rxPacketLoop()
+                    vm.txPacketOnce()
                     vm.txPacketLoop()
 
                     Timber.d("System fully operational.")

app/src/main/java/com/laseroptek/raman/ui/screens/config/ConfigScreen.kt

@@ -439,15 +439,15 @@ fun ConfigScreen(
                                     mainViewModel.saveGuideBeamToPreference()
                                 }
 
-                                /*
-                                val value = when(guideBeam.toInt()) {
-                                    0 -> 0
-                                    1 -> guideBeamMin
-                                    10 -> guideBeamMax
-                                    else -> (guideBeamMin + (guideBeam.toInt() - 1) * ((guideBeamMax - guideBeamMin) / 9))
+                                // Guide Beam step mapping (0~10):
+                                // 0 -> fixed 0
+                                // 1~10 -> min~max range in 10 steps (10 -> max)
+                                val step = guideBeam.toInt().coerceIn(0, 10)
+                                val value = if (step == 0) {
+                                    0
+                                } else {
+                                    guideBeamMin + ((step-1) * (guideBeamMax - guideBeamMin) / 9)
                                 }
-                                */
-                                val value = (guideBeamMin + (guideBeam.toInt() - 1) * ((guideBeamMax - guideBeamMin) / 9))
 
                                 Timber.d("guideBeam: $value, guideBeamMax: $guideBeamMax, guideBeamMin: $guideBeamMin")
                                 mainViewModel.txPacket(READ_WRITE.WRITE, CMD.GUIDE_BEAM, GuideBeam(value = value))
@@ -854,4 +854,4 @@ fun PreviewConfigScreen(
         mainViewModel = mainViewModel,
         configViewModel = configViewModel
     )
-}
+}

app/src/main/java/com/laseroptek/raman/ui/screens/engineer/HourItemView.kt

@@ -31,7 +31,7 @@ fun HourItemView(
     modifier: Modifier = Modifier,
     hour: Int = 0,
     onClick: () -> Unit = {},
-    title:String = ""
+    title: String = ""
 ) {
     Row(modifier = modifier,
         horizontalArrangement = Arrangement.SpaceBetween,
@@ -129,4 +129,4 @@ fun PreviewHourItemView() {
             title = "Hour Item View"
         )
     }
-}
+}

app/src/main/java/com/laseroptek/raman/ui/screens/engineer/LifeTimeView.kt

@@ -32,11 +32,11 @@ fun LifeTimeView(
 ) {
     Column(modifier = Modifier
         //.noRippleClickable(onClick = onClick)
-        .size(388.px.dp, 276.px.dp)
+        .size(388.px.dp, 258.px.dp)
         .clip(RoundedCornerShape(12.px.dp))
         .border(width = 1.px.dp, color = Color(209, 209, 209), shape = RoundedCornerShape(10.px.dp))
         .background(Color.White)
-        .padding(16.px.dp),
+        .padding(3.px.dp, 16.px.dp),
         verticalArrangement = Arrangement.SpaceEvenly,
         horizontalAlignment = Alignment.CenterHorizontally
     ) {
@@ -55,11 +55,11 @@ fun LifeTimeView(
                 ),
         )
 
-        Spacer(modifier = Modifier.height(10.px.dp))
+        Spacer(modifier = Modifier.height(2.px.dp))
 
         // Temp 0..7
         for (i in 0..lifeTimeTypes.size -1) {
-            val hour = when (i) {
+            val value = when (i) {
                 0 -> lifeTime.lamp
                 1 -> lifeTime.hp5x5
                 2 -> lifeTime.hp7x7
@@ -70,22 +70,35 @@ fun LifeTimeView(
                 7 -> lifeTime.water
                 else -> 0
             }
-            HourItemView(
-                modifier = Modifier
-                    .fillMaxSize()
-                    .weight(1f)
-                    .padding(
-                        start = 20.px.dp,
-                        end = 20.px.dp,
-                        //bottom = 10.px.dp
-                    ),
-                title = lifeTimeTypes[i],
-                hour = hour,
-                onClick = {
-                    Timber.d("onClick > Temp $i (${lifeTimeTypes[i]})")
-                    onClick.invoke(i)
-                }
-            )
+            val modifier = Modifier
+                .fillMaxSize()
+                .weight(1f)
+                .padding(
+                    start = 20.px.dp,
+                    end = 20.px.dp,
+                    //bottom = 10.px.dp
+                )
+            val title = lifeTimeTypes[i]
+            val onItemClick = {
+                Timber.d("onClick > Temp $i ($title)")
+                onClick.invoke(i)
+            }
+
+            if (i <= 5) {
+                CountItemView(
+                    modifier = modifier,
+                    title = title,
+                    count = value,
+                    onClick = onItemClick
+                )
+            } else {
+                HourItemView(
+                    modifier = modifier,
+                    title = title,
+                    hour = value,
+                    onClick = onItemClick
+                )
+            }
 
             if (i < lifeTimeTypes.size -1) {
                 HorizontalDivider(
@@ -108,4 +121,4 @@ fun LifeTimeView(
 @Composable
 fun PreviewLifeTimeView() {
     LifeTimeView()
-}
+}

app/src/main/java/com/laseroptek/raman/ui/screens/engineer/TemperatureView.kt

@@ -5,6 +5,7 @@ import androidx.compose.foundation.background
 import androidx.compose.foundation.border
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -13,15 +14,19 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
 import com.laseroptek.raman.const.temperatureTypes
 import com.laseroptek.raman.data.model.serial.Temperature
+import com.laseroptek.raman.ui.theme.RobotoTypography
 import com.laseroptek.raman.utils.ext.px
 import timber.log.Timber
 
@@ -37,7 +42,7 @@ fun TemperatureView(
         .clip(RoundedCornerShape(12.px.dp))
         .border(width = 1.px.dp, color = Color(209, 209, 209), shape = RoundedCornerShape(10.px.dp))
         .background(Color.White)
-        .padding(16.px.dp),
+        .padding(3.px.dp, 16.px.dp),
         verticalArrangement = Arrangement.SpaceEvenly,
         horizontalAlignment = Alignment.CenterHorizontally
     ) {
@@ -56,7 +61,33 @@ fun TemperatureView(
                 ),
         )
 
-        Spacer(modifier = Modifier.height(10.px.dp))
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(start = 20.px.dp, end = 20.px.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Spacer(modifier = Modifier.weight(1.5f))
+            Text(
+                modifier = Modifier.weight(1f),
+                text = "Read",
+                style = RobotoTypography.labelMedium,
+                fontSize = 12.px.sp,
+                color = Color.Black,
+                textAlign = TextAlign.End
+            )
+            Text(
+                modifier = Modifier.weight(1f),
+                text = "Write",
+                style = RobotoTypography.labelMedium,
+                fontSize = 12.px.sp,
+                color = Color.Black,
+                textAlign = TextAlign.End
+            )
+            Spacer(modifier = Modifier.weight(1f))
+        }
+
+        Spacer(modifier = Modifier.height(2.px.dp))
 
         // Tempearture
         for (i in 0..temperatureTypes.size -1) {
@@ -116,4 +147,4 @@ fun TemperatureView(
 @Composable
 fun PreviewSerialNumber() {
     TemperatureView()
-}
+}

app/src/main/java/com/laseroptek/raman/ui/screens/engineer/TwoCountItemView.kt

@@ -75,25 +75,6 @@ fun TwoCountItemView(
             )
         }
 
-        Column(
-            modifier = Modifier
-                .fillMaxWidth()
-                .weight(1f)
-                .height(30.px.dp),
-            verticalArrangement = Arrangement.Center,
-            horizontalAlignment = Alignment.Start
-        ) {
-            Text(
-                modifier = Modifier.fillMaxWidth(),
-                text = "Read",
-                style = RobotoTypography.bodyMedium,
-                fontWeight = FontWeight.Normal,
-                fontSize = 12.px.sp,
-                color = Color.Black,
-                textAlign = TextAlign.End
-            )
-        }
-
         Column(
             modifier = Modifier
                 .fillMaxWidth()
@@ -113,25 +94,6 @@ fun TwoCountItemView(
             )
         }
 
-        Column(
-            modifier = Modifier
-                .fillMaxWidth()
-                .weight(1f)
-                .height(30.px.dp),
-            verticalArrangement = Arrangement.Center,
-            horizontalAlignment = Alignment.Start
-        ) {
-            Text(
-                modifier = Modifier.fillMaxWidth(),
-                text = "Write",
-                style = RobotoTypography.bodyMedium,
-                fontWeight = FontWeight.Normal,
-                fontSize = 12.px.sp,
-                color = Color.Black,
-                textAlign = TextAlign.End
-            )
-        }
-
         Column(
             modifier = Modifier
                 //.noRippleClickable(onClick = onDeviceOpTimeClick)

app/src/main/java/com/laseroptek/raman/ui/screens/home/HomeScreen.kt

@@ -35,6 +35,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.hilt.lifecycle.viewmodel.compose.hiltViewModel
 import com.laseroptek.raman.const.LaserParameter
+import com.laseroptek.raman.const.LASER_STATUS
 import com.laseroptek.raman.const.LaserStatusType
 import com.laseroptek.raman.const.MAX_LASER_COUNT
 import com.laseroptek.raman.const.PresetButtonType
@@ -92,10 +93,18 @@ fun HomeScreen(
 
     val presetList by mainViewModel.presetList.collectAsState()
 
-    LaunchedEffect(Unit) {
+    LaunchedEffect(lampCount, lifeTime.lamp, laserStatus.laserStatus) {
         Timber.d("LaunchedEffect - HomeScreen")
         focusManager.clearFocus(force = true) // Hide the keyboard
 
+        // Ensure the system returns to StandBy when lamp thresholds are exceeded
+        val lampLifetimeLimit = lifeTime.lamp
+        val reachedLifetimeLimit = lampLifetimeLimit > 0 && lampCount >= lampLifetimeLimit
+        if (reachedLifetimeLimit && laserStatus.laserStatus != LASER_STATUS.STAND_BY) {
+            Timber.d("HomeScreen load - forcing StandBy state due to lamp count limit")
+            mainViewModel.txLaserStatusEntry(LASER_STATUS.STAND_BY)
+        }
+
         Timber.d("Attempted to hide keyboard on EngineerScreen launch")
     }
 
@@ -295,7 +304,7 @@ fun HomeScreen(
                     pulseType = pulseType,
                     handPieceType = handPiece.type,
                     type = LaserStatusType.REPETITION,
-                    angle = if (pulseType == 0 || repetitionList.size < 2) 0f else repetitionAngle,
+                    angle = if (pulseType == 0 || repetitionList.isEmpty()) 0f else repetitionAngle,
                     onChange = { angle ->
                         if (handPiece.type == 0) {
                             Toast.makeText(
@@ -306,7 +315,7 @@ fun HomeScreen(
                             return@LaserControlView
                         }
 
-                        if (pulseType == 0 || repetitionList.size < 2) {
+                        if (pulseType == 0 || repetitionList.isEmpty()) {
                             //Toast.makeText(context, "Single pulse type (0 Hz)", Toast.LENGTH_SHORT).show()
                         } else {
                             mainViewModel.onChangeRepetition(angle)
@@ -323,7 +332,7 @@ fun HomeScreen(
                             return@LaserControlView
                         }
 
-                        if (pulseType == 0 || repetitionList.size < 2) {
+                        if (pulseType == 0 || repetitionList.isEmpty()) {
                             //Toast.makeText(context, "Single pulse type (0 Hz)", Toast.LENGTH_SHORT).show()
                         } else {
                             //mainViewModel.onClickRepetition(state)
@@ -482,6 +491,18 @@ fun HomeScreen(
                             return@StandByButton
                         }
 
+                        val lampLifetimeLimit = lifeTime.lamp
+                        if (lampLifetimeLimit > 0 && lampCount >= lampLifetimeLimit) {
+                            Toast.makeText(
+                                context,
+                                "Lamp lifetime limit reached",
+                                Toast.LENGTH_SHORT
+                            ).show()
+                            return@StandByButton
+                        }
+
+
+
                         val hpCount = mainViewModel.getHPCount()
                         if (hpCount < 1) {
                             Toast.makeText(

app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/DcdSettingPopup.kt

@@ -256,7 +256,11 @@ fun DcdSettingPopup(
                                     mainViewModel.setSelectedSprayDcdIndex(i)
                                     val optionValue  = mainViewModel.sprayDcdList[i]
                                     mainViewModel.setSprayDcd(optionValue)
-                                    mainViewModel.txPacket(READ_WRITE.WRITE, CMD.SPRAY_DCD, optionValue)
+                                    mainViewModel.txPacket(
+                                        READ_WRITE.WRITE,
+                                        CMD.SPRAY_DCD,
+                                        optionValue.copy(status = 0x41)
+                                    )
 
                                     scope.launch {
                                         mainViewModel.saveSprayDcdIndexToPreference()
@@ -303,7 +307,11 @@ fun DcdSettingPopup(
                                     mainViewModel.setSelectedSprayDcdIndex(i)
                                     val optionValue  = mainViewModel.sprayDcdList[i]
                                     mainViewModel.setSprayDcd(optionValue)
-                                    mainViewModel.txPacket(READ_WRITE.WRITE, CMD.SPRAY_DCD, optionValue)
+                                    mainViewModel.txPacket(
+                                        READ_WRITE.WRITE,
+                                        CMD.SPRAY_DCD,
+                                        optionValue.copy(status = 0x41)
+                                    )
 
                                     scope.launch {
                                         mainViewModel.saveSprayDcdToPreference()
@@ -334,7 +342,7 @@ fun DcdSettingPopup(
                         modifier = Modifier
                             .fillMaxHeight()
                             .size(40.px.dp, 210.px.dp),
-                        chargeRate = gasChargeRate.toInt()
+                        chargeRate = gasChargeRate
                     )
 
                     // Icon
@@ -603,6 +611,12 @@ fun DcdSettingPopup(
                             sprayDcd
                         )
 
+                        mainViewModel.txPacket(
+                            READ_WRITE.WRITE,
+                            CMD.SPRAY_DCD,
+                            sprayDcd.copy(status = 0x41)
+                        )
+
                         mainViewModel.setSelectedSprayDcdIndex( selectedSprayDcdIndex )
                         //mainViewModel.setSprayDcdList( mainViewModel.sprayDcdList )
 

app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/DcdView.kt

@@ -97,7 +97,7 @@ fun DcdView(
 
             Column(
                 modifier = Modifier
-                    .width(45.px.dp)
+                    .width(55.px.dp)
                     .fillMaxHeight()
                 , horizontalAlignment = Alignment.CenterHorizontally
                 , verticalArrangement = Arrangement.Center
@@ -120,7 +120,7 @@ fun DcdView(
                 )
             }
 
-            Spacer( Modifier.width(10.px.dp))
+            Spacer( Modifier.width(5.px.dp))
 
             VerticalDivider(
                 color = Color(161,161,170),
@@ -128,7 +128,7 @@ fun DcdView(
                 modifier = Modifier.size(1.px.dp, 30.px.dp)
             )
 
-            Spacer( Modifier.width(10.px.dp))
+            Spacer( Modifier.width(5.px.dp))
 
             // Delay
             Timber.d("selectedSprayDcdIndex.value: ${selectedSprayDcdIndex}")

app/src/main/java/com/laseroptek/raman/ui/screens/home/dcd/GradientSlider.kt

@@ -28,14 +28,26 @@ import com.laseroptek.raman.ui.screens.main.MainViewModel
 import com.laseroptek.raman.utils.DefaultDispatcherProvider
 import com.laseroptek.raman.utils.ext.px
 import timber.log.Timber
+import kotlin.math.abs
+import kotlin.math.ceil
 
 
 @Composable
 fun GradientSlider(
     modifier: Modifier = Modifier,
-    chargeRate: Int = 0, // Value from (0 .. 100)
+    chargeRate: Float = 0f,
 ) {
-    val chargeIndex = ((chargeRate.coerceIn(0, 100) + 4) / 5).toInt()   // 0..19
+    val normalizedRate = chargeRate.coerceIn(0f, 100f)
+    val bucket = normalizedRate / 5f
+    val remainder = normalizedRate % 5f
+    val isExactMultiple = abs(remainder) < 0.0001f
+
+    val chargeIndex = when {
+        normalizedRate == 0f -> -1
+        isExactMultiple -> (bucket - 1f).toInt().coerceAtLeast(-1)
+        else -> (ceil(bucket.toDouble()).toInt() - 1)
+    }.coerceIn(-1, 19)
+
     Timber.d("chargeRate: $chargeRate, chargeIndex: $chargeIndex")
 
     Box(
@@ -103,6 +115,6 @@ fun GradientSliderPreview(
         //mainViewModel = mainViewModel
         modifier = Modifier
             .size(40.px.dp, 210.px.dp),
-        chargeRate =  20
+        chargeRate = 20f
     )
 }

app/src/main/java/com/laseroptek/raman/ui/screens/home/preset/PresetIconButton.kt

@@ -108,15 +108,15 @@ fun PresetIconButton(
         Image(
             painter = painterResource(id =
                 if (type == PresetButtonType.SAVE) {
-                    R.drawable.ic_preset_save
+                    R.drawable.ic_preset_save2
                 } else {
                     R.drawable.ic_preset_load
                 }
             ),
             contentDescription = "",
             modifier = Modifier
-                .size(20.px.dp),
-            contentScale = ContentScale.Crop
+                .size(30.px.dp),
+            contentScale = ContentScale.Fit
         )
     }
 }

app/src/main/java/com/laseroptek/raman/ui/screens/home/preset/PresetLoadPopup.kt

@@ -552,12 +552,12 @@ fun PresetLoadPopup(
                     horizontalArrangement = Arrangement.Center,
                     verticalAlignment = Alignment.CenterVertically
                 ) {
-                    Spacer(Modifier.weight(1f))
-
                     if (isEditMode) {
                         ////////////////////////////////////////////////////
                         // Edit Mode
 
+                        Spacer(modifier = Modifier.width(10.px.dp))
+
                         // Preset Delete (Delete confirm popup)
                         Box(
                             modifier = Modifier
@@ -578,7 +578,7 @@ fun PresetLoadPopup(
                             )
                         }
 
-                        Spacer(Modifier.width(10.px.dp))
+                        Spacer(Modifier.weight(1f))
 
                         // Preset Cancel (Reload selected item from mainViewModel)
                         Box(
@@ -646,7 +646,7 @@ fun PresetLoadPopup(
                                     Timber.d("onClick - Confirm Save")
 
                                     // Check empty names and conflict priority exist in the preset viewmodel's presetList
-                                    val listToValidate = presetViewModel.presetList.value
+                                    var listToValidate = presetViewModel.presetList.value
 
                                     // Check for any presets with an empty name
                                     val hasEmptyName =
@@ -678,18 +678,32 @@ fun PresetLoadPopup(
                                     }
 
                                     // Check for duplicate priorities (ignoring priority 0)
-                                    val priorityConflicts = listToValidate
-                                        .filter { it.priority > 0 } // Only consider prioritized items
-                                        .groupBy { it.priority }   // Group them by priority
-                                        .any { it.value.size > 1 } // Check if any group is larger than 1
+                                    val duplicatePriorityGroups = listToValidate
+                                        .filter { it.priority > 0 }
+                                        .groupBy { it.priority }
+                                        .filter { it.value.size > 1 }
 
-                                    if (priorityConflicts) {
-                                        Toast.makeText(
-                                            context,
-                                            "There are duplicate priorities. Please ensure each priority is unique.",
-                                            Toast.LENGTH_LONG
-                                        ).show()
-                                        return@noRippleClickable // Stop the process
+                                    if (duplicatePriorityGroups.isNotEmpty()) {
+                                        val resolvedList = listToValidate.map { it.copy() }.toMutableList()
+                                        val selectedPreset = resolvedList.getOrNull(selectedPresetIndex)
+
+                                        duplicatePriorityGroups.forEach { (priorityValue, presets) ->
+                                            val keeperId = presets
+                                                .firstOrNull { preset ->
+                                                    selectedPreset != null && preset.id == selectedPreset.id
+                                                }
+                                                ?.id
+                                                ?: presets.first().id
+
+                                            resolvedList.forEachIndexed { index, preset ->
+                                                if (preset.priority == priorityValue && preset.id != keeperId) {
+                                                    resolvedList[index] = preset.copy(priority = 0)
+                                                }
+                                            }
+                                        }
+
+                                        presetViewModel.setPresetList(resolvedList)
+                                        listToValidate = resolvedList
                                     }
 
                                     Timber.d("Validation successful. Saving list to MainViewModel.")
@@ -729,7 +743,11 @@ fun PresetLoadPopup(
                                 contentScale = ContentScale.Crop
                             )
                         }
+
+                        Spacer(modifier = Modifier.width(10.px.dp))
                     } else {
+                        Spacer(Modifier.weight(1f))
+
                         ////////////////////////////////////////////////////
                         // Select Mode - hide Keyboard
                         focusManager.clearFocus(force = true) // Hide the keyboard
@@ -762,21 +780,25 @@ fun PresetLoadPopup(
                                 .noRippleClickable(onClick = {
                                     Timber.d("onClick - Preset Load")
 
-                                    val selectedPreset =
-                                        presetViewModel.getPreset(selectedPresetIndex)
-                                    val priority =
-                                        selectedPreset?.priority ?: 0
+                                    val selectedPreset = presetViewModel.getPreset(selectedPresetIndex)
+                                    if (selectedPreset == null) {
+                                        Timber.w("onClick - Preset Load: selectedPreset is null. index=$selectedPresetIndex")
+                                        return@noRippleClickable
+                                    }
+                                    val priority = selectedPreset.priority
 
                                     Timber.d("onClick - Preset Load ($priority)")
 
-//                                    if (priority > 0) {   // TODO : 검증 필요
+                                    if (priority > 0) {
                                         mainViewModel.setSelectedPresetIndex( priority )
                                         mainViewModel.applyPreset(priority)
-                                        presetViewModel.clearPreset()
-                                        onClick.invoke(false)
-//                                    } else {
-//                                        Timber.d("SKIP - Preset Load ($priority)")
-//                                    }
+                                    } else {
+                                        // 우선순위가 NONE인 경우, 인덱스 설정 X
+                                        mainViewModel.setSelectedPresetIndex(0)
+                                        mainViewModel.applyPreset(selectedPreset)
+                                    }
+                                    presetViewModel.clearPreset()
+                                    onClick.invoke(false)
                                 })
                                 .size(40.px.dp)
                                 .background(Color.Transparent)
@@ -790,6 +812,8 @@ fun PresetLoadPopup(
                                 contentScale = ContentScale.Crop
                             )
                         }
+
+                        Spacer(modifier = Modifier.width(10.px.dp))
                     }
                 }
 

app/src/main/java/com/laseroptek/raman/ui/screens/home/preset/PresetViewModel.kt

@@ -28,6 +28,7 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
 import timber.log.Timber
+import kotlin.math.abs
 import javax.inject.Inject
 
 @HiltViewModel
@@ -80,6 +81,49 @@ class PresetViewModel @Inject constructor(
         _repetitionList.value = r
     }
 
+    private data class ResolvedRepetitionContext(
+        val fluence: Float,
+        val repetitionOptions: List<Float>,
+    )
+
+    private fun resolveRepetitionContext(
+        pulseWidth: Float,
+        fluence: Float,
+    ): ResolvedRepetitionContext {
+        val availableFluenceList = energyTable.value.getKey2ListForKey1(pulseWidth)
+        val resolvedFluence = availableFluenceList.minByOrNull { abs(it - fluence) }
+            ?: availableFluenceList.firstOrNull()
+            ?: fluence
+
+        val hzType = hzTable.value.getValue(pulseWidth, resolvedFluence)
+        val repetitionOptions = RepetitionsByColorKey[hzType] ?: RepetitionsByColorKey[KEY_YELLOW].orEmpty()
+
+        if (hzType == null) {
+            Timber.w(
+                "No hzType found for pulseWidth=%s, fluence=%s. Falling back to default repetition list.",
+                pulseWidth,
+                resolvedFluence
+            )
+        }
+
+        setRepetitionList(repetitionOptions)
+        return ResolvedRepetitionContext(
+            fluence = resolvedFluence,
+            repetitionOptions = repetitionOptions,
+        )
+    }
+
+    private fun resolveNearestLowerOrEqualRepetition(
+        currentRepetition: Float,
+        repetitionOptions: List<Float>,
+    ): Float {
+        return repetitionOptions
+            .filter { it <= currentRepetition }
+            .maxOrNull()
+            ?: repetitionOptions.minOrNull()
+            ?: currentRepetition
+    }
+
     fun loadHzTable(handPieceType: Int) {
         Timber.d("loadHzTable($handPieceType)")
 
@@ -251,21 +295,17 @@ class PresetViewModel @Inject constructor(
 
             // 4. fluence update (energyTable)
             val newFluenceList = energyTable.value.getKey2ListForKey1(newPulseWidth)
-            val newFluence = newFluenceList.get(0)
+            val newFluence = newFluenceList.firstOrNull() ?: currentList[index].fluence
 
             // 5. repetition update (hzTable)
-            val hzType = hzTable.value.getValue(newPulseWidth, newFluence)
-            Timber.d("hzType: ${hzType}")
-            val list = RepetitionsByColorKey.get(hzType)!!
-            setRepetitionList( list )
-
-            val newRepetitionIndex = 0
-            val newRepetition = list[newRepetitionIndex]
+            val repetitionContext = resolveRepetitionContext(newPulseWidth, newFluence)
+            Timber.d("Resolved repetition options for handPieceType update: ${repetitionContext.repetitionOptions}")
+            val newRepetition = repetitionContext.repetitionOptions.firstOrNull() ?: currentList[index].repetition
 
             val updatedPreset = currentList[index].copy(
                 handPieceType = newHandPieceType,
                 pulseWidth = newPulseWidth,
-                fluence = newFluence,
+                fluence = repetitionContext.fluence,
                 repetition = newRepetition
             )
             currentList[index] = updatedPreset
@@ -311,20 +351,18 @@ class PresetViewModel @Inject constructor(
 
         // 3. update fluence
         val newFluenceList = energyTable.value.getKey2ListForKey1(newPulseWidth)
-        val newFluenceIndex = 0
-        val newFluence = newFluenceList.get(newFluenceIndex)
+        val newFluence = newFluenceList.firstOrNull() ?: currentList[index].fluence
         
         // 4. update repetition
-        val hzType = hzTable.value.getValue(newPulseWidth, newFluence)
-        val list = RepetitionsByColorKey[hzType]!!
-        setRepetitionList( list )
-
-        val newRepetitionIndex = 0
-        val newRepetition = repetitionList.value[newRepetitionIndex]
+        val repetitionContext = resolveRepetitionContext(newPulseWidth, newFluence)
+        val newRepetition = resolveNearestLowerOrEqualRepetition(
+            currentRepetition = currentList[index].repetition,
+            repetitionOptions = repetitionContext.repetitionOptions,
+        )
 
         val updatedPreset = currentList[index].copy(
             pulseWidth = newPulseWidth,
-            fluence = newFluence,
+            fluence = repetitionContext.fluence,
             repetition = newRepetition
         )
         currentList[index] = updatedPreset
@@ -354,17 +392,16 @@ class PresetViewModel @Inject constructor(
         }
 
         // 3. update repetition (0)
-        val hzType = hzTable.value.getValue(pulseWidth, newFluence)
-        val list = RepetitionsByColorKey[hzType]!!
-        setRepetitionList( list )
-
-        val newRepetitionIndex = 0
-        val newRepetition = repetitionList.value[newRepetitionIndex]
+        val repetitionContext = resolveRepetitionContext(pulseWidth, newFluence)
+        val newRepetition = resolveNearestLowerOrEqualRepetition(
+            currentRepetition = currentList[index].repetition,
+            repetitionOptions = repetitionContext.repetitionOptions,
+        )
 
         // The original code here had a bug: it was updating `pulseWidth = newFluence`
         // It should be `fluence = newFluence`
         val updatedPreset = currentList[index].copy(
-            fluence = newFluence,
+            fluence = repetitionContext.fluence,
             repetition = newRepetition
         )
         currentList[index] = updatedPreset
@@ -385,20 +422,28 @@ class PresetViewModel @Inject constructor(
         loadHzTable(handPieceType)
 
         // update repetition
-        val hzType = hzTable.value.getValue(pulseWidth, fluence)
-        val list = RepetitionsByColorKey[hzType]!!
-        setRepetitionList( list )
+        val repetitionContext = resolveRepetitionContext(pulseWidth, fluence)
+        val currentRepetitionList = repetitionContext.repetitionOptions
 
-        val newRepetitionIndex = repetitionList.value.indexOf(repetition).takeIf { it != -1 } ?: 0
+        val newRepetitionIndex = currentRepetitionList.indexOf(repetition).takeIf { it != -1 } ?: 0
         val newRepetition = if (isUp == UpDownState.Up) {
-            // Original logic: repetitionIndex < PulseDurations.size -1 (Likely a typo, should be Repetitions.size)
-            if (newRepetitionIndex < repetitionList.value.size - 1) repetitionList.value[newRepetitionIndex + 1] else repetition
+            if (newRepetitionIndex < currentRepetitionList.size - 1) {
+                currentRepetitionList[newRepetitionIndex + 1]
+            } else {
+                repetition
+            }
         } else {
-            // Original logic: repetitionIndex > 1
-            if (newRepetitionIndex > 0) repetitionList.value[newRepetitionIndex - 1] else repetition
+            if (newRepetitionIndex > 0) {
+                currentRepetitionList[newRepetitionIndex - 1]
+            } else {
+                repetition
+            }
         }
 
-        val updatedPreset = currentList[index].copy(repetition = newRepetition)
+        val updatedPreset = currentList[index].copy(
+            fluence = repetitionContext.fluence,
+            repetition = newRepetition
+        )
         currentList[index] = updatedPreset
         //_presetList.value = currentList
         setPresetList(currentList)
@@ -449,4 +494,4 @@ class PresetViewModel @Inject constructor(
     init {
         Timber.d("PresetViewModel init")
     }
-}
+}

app/src/main/java/com/laseroptek/raman/ui/screens/info/InfoViewModel.kt

@@ -1,10 +1,14 @@
 package com.laseroptek.raman.ui.screens.info
 
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
+import com.laseroptek.raman.repository.PreferenceRepository
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.flow.collectLatest
+import kotlinx.coroutines.launch
 import timber.log.Timber
 import javax.inject.Inject
 
@@ -25,10 +29,13 @@ data class ChartUiState(
     val chamber2State: Boolean = true,
     val basePlateState: Boolean = true,
     val waterState: Boolean = true,
-)
+) {
+    companion object
+}
 
 @HiltViewModel
 class InfoViewModel @Inject constructor(
+    private val preferenceRepository: PreferenceRepository,
 ) : ViewModel() {
 
     // This is the single source of truth for the checkbox states.
@@ -39,7 +46,7 @@ class InfoViewModel @Inject constructor(
     fun toggleLine(line: ChartLine) {
         // .update is a thread-safe way to update the state.
         _chartUiState.update { currentState ->
-            when (line) {
+            val updatedState = when (line) {
                 ChartLine.INT_TEMP -> currentState.copy(intTempState = !currentState.intTempState)
                 ChartLine.EXT_TEMP -> currentState.copy(extTempState = !currentState.extTempState)
                 ChartLine.INT_HUMIDITY -> currentState.copy(intHumidityState = !currentState.intHumidityState)
@@ -50,10 +57,51 @@ class InfoViewModel @Inject constructor(
                 ChartLine.BASE_PLATE -> currentState.copy(basePlateState = !currentState.basePlateState)
                 ChartLine.WATER -> currentState.copy(waterState = !currentState.waterState)
             }
+            persistChartUiState(updatedState)
+            updatedState
         }
     }
 
     init {
         Timber.d("InfoViewModel init")
+        viewModelScope.launch {
+            preferenceRepository.getInfoChartLineStates().collectLatest { savedStates ->
+                if (savedStates.isEmpty()) return@collectLatest
+                _chartUiState.update { ChartUiState.fromPreference(savedStates) }
+            }
+        }
     }
-}
+
+    private fun persistChartUiState(state: ChartUiState) {
+        viewModelScope.launch {
+            preferenceRepository.saveInfoChartLineStates(state.toPreferenceMap())
+        }
+    }
+}
+
+private fun ChartUiState.toPreferenceMap(): Map<String, Boolean> = mapOf(
+    ChartLine.INT_TEMP.name to intTempState,
+    ChartLine.EXT_TEMP.name to extTempState,
+    ChartLine.INT_HUMIDITY.name to intHumidityState,
+    ChartLine.EXT_HUMIDITY.name to extHumidityState,
+    ChartLine.KTP.name to ktpState,
+    ChartLine.CHAMBER1.name to chamber1State,
+    ChartLine.CHAMBER2.name to chamber2State,
+    ChartLine.BASE_PLATE.name to basePlateState,
+    ChartLine.WATER.name to waterState,
+)
+
+private fun ChartUiState.Companion.fromPreference(savedStates: Map<String, Boolean>): ChartUiState {
+    val defaults = ChartUiState()
+    return ChartUiState(
+        intTempState = savedStates[ChartLine.INT_TEMP.name] ?: defaults.intTempState,
+        extTempState = savedStates[ChartLine.EXT_TEMP.name] ?: defaults.extTempState,
+        intHumidityState = savedStates[ChartLine.INT_HUMIDITY.name] ?: defaults.intHumidityState,
+        extHumidityState = savedStates[ChartLine.EXT_HUMIDITY.name] ?: defaults.extHumidityState,
+        ktpState = savedStates[ChartLine.KTP.name] ?: defaults.ktpState,
+        chamber1State = savedStates[ChartLine.CHAMBER1.name] ?: defaults.chamber1State,
+        chamber2State = savedStates[ChartLine.CHAMBER2.name] ?: defaults.chamber2State,
+        basePlateState = savedStates[ChartLine.BASE_PLATE.name] ?: defaults.basePlateState,
+        waterState = savedStates[ChartLine.WATER.name] ?: defaults.waterState,
+    )
+}

app/src/main/java/com/laseroptek/raman/ui/screens/main/MainViewModel.kt

@@ -134,6 +134,7 @@ import kotlinx.coroutines.joinAll
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import timber.log.Timber
+import kotlin.math.abs
 import javax.inject.Inject
 import kotlin.experimental.or
 import kotlin.time.Duration.Companion.milliseconds
@@ -583,22 +584,22 @@ class MainViewModel @Inject constructor(
         saveGuideBeamMinToPreference()
         saveGuideBeamMaxToPreference()
 
-        // After updating the state, send the packet
-        val newMin = guideBeamMin.value // get the potentially updated value
-        val newMax = guideBeamMax.value // get the potentially updated value
-        val guideBeam = guideBeam.value.toInt()
+        // Engineer 화면에서는 Min/Max 버튼에 따라 표시된 Min 또는 Max 값을 그대로 송신
+        val newMin = guideBeamMin.value
+        val newMax = guideBeamMax.value
+        val value = when (state) {
+            MinMaxUpDownState.MinDown,
+            MinMaxUpDownState.MinUp,
+            MinMaxUpDownState.MinLongDown,
+            MinMaxUpDownState.MinLongUp -> newMin
 
-        /*
-        val value = when(guideBeamValue) {
-            0 -> 0
-            1 -> newMin
-            10 -> newMax
-            else -> (newMin + (guideBeamValue - 1) * ((newMax - newMin) / 9))
+            MinMaxUpDownState.MaxDown,
+            MinMaxUpDownState.MaxUp,
+            MinMaxUpDownState.MaxLongDown,
+            MinMaxUpDownState.MaxLongUp -> newMax
         }
-        */
-        val value = (newMin + (guideBeam - 1) * ((newMax - newMin) / 9))
 
-        Timber.d("guideBeam: $value, guideBeam: $guideBeam, guideBeamMax: $newMax, guideBeamMin: $newMin")
+        Timber.d("Engineer guideBeam tx value: $value, guideBeamMax: $newMax, guideBeamMin: $newMin")
         txPacket(READ_WRITE.WRITE, CMD.GUIDE_BEAM, GuideBeam(value = value))
     }
 
@@ -814,24 +815,62 @@ class MainViewModel @Inject constructor(
     }
 
     fun txPacketOnce() {
-        // viewModel init 으로 이동. 필요.
-        // 경고 정보 조회 (주기적 heart beat)
-        // repeatOnLifecycle은 Activity가 포그라운드에 있을 때로 한정지어, 특정 Lifecycle이 Trigger 되었을 때 동작하도록 만드는 block 임.
+        viewModelScope.launch(dispatcherProvider.io) {
+            // txPacketOnce is called during app startup.
+            // Because serial open() is started in rxPacketLoop() asynchronously,
+            // FD can still be -1 here (startup race). Wait briefly before first TX burst.
+            if (!waitUntilSerialReady()) {
+                Timber.e("txPacketOnce skipped: serial port is not ready (fd=%d)", serialPortRepository.getFD())
+                return@launch
+            }
 
-        // tx Version Read
-        txPacket(READ_WRITE.READ, CMD.VERSION, byteArrayOf(0x41.toByte()))
+            // viewModel init 으로 이동. 필요.
+            // 경고 정보 조회 (주기적 heart beat)
+            // repeatOnLifecycle은 Activity가 포그라운드에 있을 때로 한정지어, 특정 Lifecycle이 Trigger 되었을 때 동작하도록 만드는 block 임.
 
-        // tx Q-Switch Write
-        txPacket(READ_WRITE.WRITE, CMD.Q_SWITCH, qSwitch.value)
+            // tx Version Read
+            txPacket(READ_WRITE.READ, CMD.VERSION, byteArrayOf(0x41.toByte()))
 
-        // tx Guide Beam Write
-        txPacket(READ_WRITE.WRITE, CMD.GUIDE_BEAM, GuideBeam(value = guideBeam.value.toInt()))
+            // tx Q-Switch Write
+            txPacket(READ_WRITE.WRITE, CMD.Q_SWITCH, qSwitch.value)
 
-        // tx DCD_GAS Write (DEFAULT VALUE)
-        txPacket(READ_WRITE.WRITE, CMD.DCD_GAS, dcdGas.value.copy(status = 0x50))
+            // tx Oven Write (align with Engineer KTP write source)
+            txPacket(READ_WRITE.WRITE, CMD.OVEN, Oven(ktp = temperature_write.value.ktp))
 
-        // tx SPRAY_DCD Write (DEFAULT VALUE)
-        txPacket(READ_WRITE.WRITE, CMD.SPRAY_DCD, sprayDcd.value)
+            // tx Guide Beam Write
+            txPacket(READ_WRITE.WRITE, CMD.GUIDE_BEAM, GuideBeam(value = getGuideBeamTxValue()))
+
+            // tx DCD_GAS Write (DEFAULT VALUE)
+            txPacket(READ_WRITE.WRITE, CMD.DCD_GAS, dcdGas.value.copy(status = 0x50))
+
+            // tx SPRAY_DCD Write (DEFAULT VALUE)
+            txPacket(READ_WRITE.WRITE, CMD.SPRAY_DCD, sprayDcd.value.copy(status = 0x41))
+        }
+    }
+
+    private suspend fun waitUntilSerialReady(
+        timeoutMillis: Long = 2000L,
+        pollIntervalMillis: Long = 20L
+    ): Boolean {
+        // Poll FD until open() completes, with a bounded timeout to avoid blocking forever.
+        val start = System.currentTimeMillis()
+        while (System.currentTimeMillis() - start < timeoutMillis) {
+            if (serialPortRepository.getFD() != -1) return true
+            delay(pollIntervalMillis)
+        }
+        return serialPortRepository.getFD() != -1
+    }
+
+    // Guide Beam step mapping (0~10)
+    // 0 -> fixed 0
+    // 1~10 -> min~max range in 10 steps (10 -> max)
+    private fun getGuideBeamTxValue(): Int {
+        val step = guideBeam.value.toInt().coerceIn(0, 10)
+        return if (step == 0) {
+            0
+        } else {
+            guideBeamMin.value + ((step - 1) * (guideBeamMax.value - guideBeamMin.value) / 9)
+        }
     }
 
     // Example: Emitting an event after a delay
@@ -2043,28 +2082,58 @@ class MainViewModel @Inject constructor(
         Timber.d("preset: ${preset}")
 
         val newPreset = if (preset == null) {
+            val defaultPulseWidth = PulseDurations.first()
             Preset(
                 handPieceType = handPiece.value.type,
                 priority = priority,
-                fluence = energyTable.value.getKey2ListForKey1(0.5f).first(),
+                fluence = energyTable.value.getKey2ListForKey1(defaultPulseWidth).firstOrNull() ?: 0f,
                 repetition = repetitionList.value.first(),
-                pulseWidth = PulseDurations.first(),
+                pulseWidth = defaultPulseWidth,
             )
         } else {
             preset
         }
+        applyPreset(newPreset)
+    }
 
-        val fluenceList = energyTable.value.getKey2ListForKey1(newPreset.pulseWidth)
+    fun applyPreset(preset: Preset) {
+        val newPreset = preset.copy()
 
         val pulseStep = PulseDurations.indexOf(newPreset.pulseWidth).takeIf {it != -1} ?: 0
-        val fluenceStep = fluenceList.indexOf(newPreset.fluence).takeIf {it != -1} ?: 0
-        val repetitionStep = repetitionList.value.indexOf(newPreset.repetition).takeIf {it != -1} ?: 0
+        val resolvedPulseWidth = PulseDurations[pulseStep]
+
+        // 프리셋의 pulseWidth 기준으로 실제 사용 가능한 fluence 목록을 먼저 동기화한다.
+        val newFluenceList = energyTable.value.getKey2ListForKey1(resolvedPulseWidth)
+        if (newFluenceList != fluenceList.value) {
+            setFluenceList(newFluenceList)
+        }
+
+        // 프리셋 fluence가 정확히 없을 수 있으므로, 가장 가까운 값으로 보정한다.
+        val resolvedFluence = newFluenceList.minByOrNull { abs(it - newPreset.fluence) }
+            ?: newFluenceList.firstOrNull()
+            ?: 0f
+        val fluenceStep = newFluenceList.indexOf(resolvedFluence).takeIf { it != -1 } ?: 0
+
+        // 보정된 (pulseWidth, fluence) 조합으로 repetition 테이블을 다시 계산한다.
+        val hzType = hzTable.value.getValue(resolvedPulseWidth, resolvedFluence)
+        val newRepetitionList = RepetitionsByColorKey[hzType] ?: RepetitionsByColorKey[KEY_YELLOW]!!
+        if (newRepetitionList != repetitionList.value) {
+            setRepetitionList(newRepetitionList)
+        }
+        val repetitionStep = newRepetitionList.indexOf(newPreset.repetition).takeIf { it != -1 } ?: 0
 
         Timber.d("pulseStep: ${pulseStep} fluenceStep: ${fluenceStep} repetitionStep: ${repetitionStep}")
 
         val pulseAngle = pulseStep.stepToDegree(totalSteps = PulseDurations.size)
-        val fluenceAngle = fluenceStep.stepToDegree(totalSteps = fluenceList.size)
-        val repetitionAngle = repetitionStep.stepToDegree(totalSteps = repetitionList.value.size)
+        val fluenceAngle = if (newFluenceList.isNotEmpty()) {
+            fluenceStep.stepToDegree(totalSteps = newFluenceList.size)
+        } else {
+            0f
+        }
+        val repetitionAngle = repetitionIndexToAngle(
+            index = repetitionStep,
+            totalSteps = newRepetitionList.size,
+        )
 
         Timber.d("pulseStep: ${pulseStep} fluenceStep: ${fluenceStep} repetitionStep: ${repetitionStep}")
 
@@ -2094,30 +2163,35 @@ class MainViewModel @Inject constructor(
             setFluenceList(newFluenceList)
         }
 
+        // 2-1. Resolve and apply fluence by value (not by old angle/index).
+        val resolvedFluence = newFluenceList.minByOrNull { abs(it - newFluence) } ?: 0f
+        val resolvedFluenceIndex = newFluenceList.indexOf(resolvedFluence).takeIf { it >= 0 } ?: 0
+        if (newFluenceList.isNotEmpty()) {
+            setFluenceAngle(resolvedFluenceIndex.stepToDegree(totalSteps = newFluenceList.size))
+        }
+
         // 3. Safely Update Repetition List (Prevents NullPointerException)
-        val newHzType = hzTable.value.getValue(newPulseDuration, newFluence)
+        val newHzType = hzTable.value.getValue(newPulseDuration, resolvedFluence)
         val newRepetitionList = RepetitionsByColorKey[newHzType] ?: RepetitionsByColorKey[KEY_YELLOW]!!
         if (newRepetitionList != repetitionList.value) {
             setRepetitionList(newRepetitionList)
         }
 
-        // Smartly preserve Repetition Angle
-        // 4. Check if the old repetition value exists in the new list.
-        val oldRepetitionIndex = if (currentRepetitionValue != null) {
-            newRepetitionList.indexOf(currentRepetitionValue)
-        } else {
-            -1
-        }
+        // 4. Resolve and apply repetition by value (not by old angle/index).
+        val targetRepetition = currentRepetitionValue ?: 0f
+        val resolvedRepetition = newRepetitionList.minByOrNull { abs(it - targetRepetition) } ?: 0f
+        val resolvedRepetitionIndex = newRepetitionList.indexOf(resolvedRepetition).takeIf { it >= 0 } ?: 0
 
-        if (oldRepetitionIndex != -1) {
-            // If the old value exists, set the slider to that position.
-            val preservedAngle = oldRepetitionIndex.stepToDegree(totalSteps = newRepetitionList.size)
-            setRepetitionAngle(preservedAngle)
-            Timber.d("Repetition value $currentRepetitionValue preserved at new angle $preservedAngle.")
+        if (newRepetitionList.isNotEmpty()) {
+            val resolvedRepetitionAngle = repetitionIndexToAngle(
+                index = resolvedRepetitionIndex,
+                totalSteps = newRepetitionList.size,
+            )
+            setRepetitionAngle(resolvedRepetitionAngle)
+            Timber.d("Resolved repetition by value: old=$currentRepetitionValue, new=$resolvedRepetition, angle=$resolvedRepetitionAngle")
         } else {
-            // If it doesn't exist, THEN reset the slider to the beginning.
             setRepetitionAngle(0f)
-            Timber.d("Repetition value $currentRepetitionValue not supported in new list. Resetting angle.")
+            Timber.d("Repetition list is empty. Resetting repetition angle to 0f.")
         }
 
         // 5. Conditionally reset the fluence angle slider if needed
@@ -2130,7 +2204,7 @@ class MainViewModel @Inject constructor(
         // 6. Any change invalidates the current preset selection.
         setSelectedPresetIndex(0)
 
-        Timber.d("Updated Laser Parameters: pulse=$newPulseDuration, fluence=$newFluence -> newRepListSize=${newRepetitionList.size}")
+        Timber.d("Updated Laser Parameters: pulse=$newPulseDuration, fluence=$resolvedFluence -> newRepListSize=${newRepetitionList.size}")
     }
 
     /**
@@ -2150,13 +2224,16 @@ class MainViewModel @Inject constructor(
         setPulseAngle(newPulseStep.stepToDegree(totalSteps = PulseDurations.size))
 
         val newPulseDuration = PulseDurations[newPulseStep]
-        // When pulse duration changes via slider, we use the first available fluence for the new list.
-        val firstFluence = energyTable.value.getKey2ListForKey1(newPulseDuration).firstOrNull() ?: 0f
+        // Keep the current fluence value when pulse duration changes via slider.
+        val currentFluenceStep = fluenceAngle.value.degreeToStep(totalSteps = fluenceList.value.size)
+        val currentFluence = fluenceList.value.getOrNull(currentFluenceStep)
+            ?: energyTable.value.getKey2ListForKey1(newPulseDuration).firstOrNull()
+            ?: 0f
 
-        // Call the centralized helper, resetting the fluence slider.
+        // Call the centralized helper using the preserved fluence value.
         updateLaserParameters(
             newPulseDuration = newPulseDuration,
-            newFluence = firstFluence,
+            newFluence = currentFluence,
         )
     }
 
@@ -2168,12 +2245,17 @@ class MainViewModel @Inject constructor(
             setPulseAngle(newStep.stepToDegree(totalSteps = PulseDurations.size))
 
             val newPulseDuration = PulseDurations[newStep]
-            val firstFluence = energyTable.value.getKey2ListForKey1(newPulseDuration).firstOrNull() ?: 0f
+            // Keep the current fluence value when pulse duration changes via slider.
+            val currentFluenceStep = fluenceAngle.value.degreeToStep(totalSteps = fluenceList.value.size)
+            val currentFluence = fluenceList.value.getOrNull(currentFluenceStep)
+                ?: energyTable.value.getKey2ListForKey1(newPulseDuration).firstOrNull()
+                ?: 0f
+
 
             // Call the centralized helper, resetting the fluence slider.
             updateLaserParameters(
                 newPulseDuration = newPulseDuration,
-                newFluence = firstFluence,
+                newFluence = currentFluence,
             )
         }
     }
@@ -2216,8 +2298,12 @@ class MainViewModel @Inject constructor(
 
     fun onChangeRepetition(angle: Float) {
         // This logic is simple and has no complex dependencies, so it can remain as is.
-        if (angle != repetitionAngle.value) {
-            setRepetitionAngle(angle)
+        val normalizedAngle = repetitionIndexToAngle(
+            index = angle.degreeToStep(totalSteps = repetitionList.value.size),
+            totalSteps = repetitionList.value.size,
+        )
+        if (normalizedAngle != repetitionAngle.value) {
+            setRepetitionAngle(normalizedAngle)
         }
         setSelectedPresetIndex(0)
     }
@@ -2228,12 +2314,23 @@ class MainViewModel @Inject constructor(
         val newStep = if (state == UpDownState.Up) currentStep + 1 else currentStep - 1
 
         if (newStep in repetitionList.value.indices) {
-            val newRepetitionAngle = newStep.stepToDegree(totalSteps = repetitionList.value.size)
+            val newRepetitionAngle = repetitionIndexToAngle(
+                index = newStep,
+                totalSteps = repetitionList.value.size,
+            )
             setRepetitionAngle(newRepetitionAngle)
             setSelectedPresetIndex(0)
         }
     }
 
+    private fun repetitionIndexToAngle(index: Int, totalSteps: Int): Float {
+        return when {
+            totalSteps <= 0 -> 0f
+            totalSteps == 1 -> 270f
+            else -> index.stepToDegree(totalSteps = totalSteps)
+        }
+    }
+
     /**
      * Perform all heavy I/O in a single background block.
      * This prevents the "Skipped frames" caused by 30+ sequential bridge calls
@@ -2286,4 +2383,4 @@ class MainViewModel @Inject constructor(
         // ONLY do light, non-IO variable initialization here.
         // DO NOT call load... functions here.
     }
-}
+}

app/src/main/java/com/laseroptek/raman/utils/ext/PacketExtension.kt

@@ -487,7 +487,7 @@ fun QSwitch.toByteArray(): ByteArray {
     val delayTimeIntegerPart = this.delayTime.toInt()
     val delayTimeFractionPart = ((this.delayTime - delayTimeIntegerPart) * 10).toInt()
     val intervalTimeIntegerPart = this.intervalTime.toInt()
-    val intervalTimeFractionPart = ((this.intervalTime - delayTimeIntegerPart) * 10).toInt()
+    val intervalTimeFractionPart = ((this.intervalTime - intervalTimeIntegerPart) * 10).toInt()
 
     val delayTimeArray = byteArrayOf(
         ((delayTimeIntegerPart.getNthDigit(2) + 0x30) and 0xFF).toByte(),

docs/change_summary_2026-03-04.md

@@ -0,0 +1,23 @@
+# 변경 요약 (2026-03-04)
+
+이 문서는 현재 `git diff` 기준으로 반영된 변경을 정리합니다.
+
+## 1) 시리얼 초기 전송 누락(Startup race) 대응
+
+### 변경 파일
+- `app/src/main/java/com/laseroptek/raman/ui/MainActivity.kt`
+- `app/src/main/java/com/laseroptek/raman/ui/screens/main/MainViewModel.kt`
+
+### 변경 내용
+- `MainActivity.initialize()`의 시리얼 시작 순서를 조정
+  - 이전: `txPacketOnce()` -> `rxPacketLoop()` -> `txPacketLoop()`
+  - 이후: `rxPacketLoop()` -> `txPacketOnce()` -> `txPacketLoop()`
+- `MainViewModel.txPacketOnce()`를 코루틴(IO)에서 실행하도록 변경
+- `waitUntilSerialReady()` 추가
+  - 최대 2초 동안 20ms 간격으로 `FD != -1` 확인
+  - 준비 실패 시 에러 로그 후 초기 TX 중단
+- 관련 설명 주석 추가
+
+### 의도/효과
+- 앱 시작 직후 `open()` 완료 전 TX가 먼저 발생하는 레이스를 완화/방어
+- 포트 미준비 상태(`FD == -1`)에서 write가 호출되어 초기 패킷이 누락되는 문제를 줄임

docs/change_summary_2026-03-10.md

@@ -0,0 +1,237 @@
+# 변경 소스 설명 (2026-03-10)
+
+## 대상
+
+현재 워크스페이스에서 수정된 항목은 아래와 같습니다.
+
+- `app/src/main/java/com/laseroptek/raman/ui/screens/home/preset/PresetViewModel.kt`
+- `app/build.gradle.kts`
+
+실제 로직 변경은 `PresetViewModel.kt`에 있습니다.
+`app/build.gradle.kts`는 `git status`상 수정으로 보이지만, 확인한 텍스트 diff 기준으로는 의미 있는 코드 변경이 보이지 않았습니다. 줄바꿈(CRLF/LF) 같은 형식 변화일 가능성이 큽니다.
+
+## 이 파일이 하는 일
+
+`PresetViewModel.kt`는 프리셋 화면의 상태를 관리하는 코드입니다.
+
+쉽게 말하면 사용자가 화면에서 아래 값을 올리거나 내릴 때:
+
+- 핸드피스 종류
+- 펄스폭 (`pulseWidth`)
+- 에너지 단계 (`fluence`)
+- 반복수 (`repetition`)
+
+그 조합에 맞는 다음 값들을 다시 계산해서 화면에 반영하는 역할입니다.
+
+## 이번 변경의 핵심
+
+핵심은 반복수(`repetition`) 계산을 더 안전하고 더 자연스럽게 만든 것입니다.
+
+이전 방식은 다음 문제가 생길 수 있었습니다.
+
+- `pulseWidth`와 `fluence` 조합이 테이블에 정확히 없으면 적절한 반복수 목록을 못 찾을 수 있음
+- 못 찾았을 때 강제 `!!` 사용으로 앱이 비정상 종료될 가능성이 있음
+- `fluence` 변경 시 다른 필드를 잘못 갱신하는 버그가 있었음
+
+이번 수정에서는 공통 계산 함수가 추가되어, 값이 정확히 일치하지 않아도 가장 가까운 `fluence`를 찾아서 처리하도록 바뀌었습니다.
+
+또한 `pulse duration`이나 `fluence`를 바꿀 때 repetition이 무조건 목록의 첫 값(`1Hz` 등)으로 초기화되지 않도록 규칙이 바뀌었습니다.
+
+새 규칙은 아래와 같습니다.
+
+- 현재 repetition 값 이하인 후보들 중
+- 가장 큰 값을 선택
+- 만약 그런 값이 하나도 없으면 새 목록의 최소값 사용
+
+예를 들어 현재 repetition이 `10Hz`이고, 새 조건에서 가능한 repetition 목록이 `1, 3, 5, 8`이라면 결과는 `8Hz`가 됩니다.
+즉, "현재 값에 최대한 가깝게 유지하되, 새 조건에서 허용되는 값으로 내린다"는 방식입니다.
+
+## 새로 추가된 구조
+
+### 1. `ResolvedRepetitionContext`
+
+```kotlin
+private data class ResolvedRepetitionContext(
+    val fluence: Float,
+    val repetitionOptions: List<Float>,
+)
+```
+
+이 구조는 반복수 계산 결과를 한 번에 묶어서 전달하기 위한 작은 데이터 상자입니다.
+
+- `fluence`: 실제로 확정된 에너지 값
+- `repetitionOptions`: 그 조건에서 선택 가능한 반복수 목록
+
+### 2. `resolveRepetitionContext()`
+
+이 함수가 이번 수정의 핵심입니다.
+
+동작 순서는 아래와 같습니다.
+
+1. 현재 `pulseWidth`에 대해 사용 가능한 `fluence` 목록을 가져옵니다.
+2. 사용자가 가지고 있던 `fluence`와 가장 가까운 실제 값을 찾습니다.
+3. 그 조합으로 `hzType`을 찾습니다.
+4. `hzType`에 맞는 반복수 목록을 가져옵니다.
+5. 만약 `hzType`을 찾지 못하면 기본값(`KEY_YELLOW`) 목록으로 대체합니다.
+6. 최종 반복수 목록을 `setRepetitionList()`로 화면 상태에 반영합니다.
+
+즉, 예전보다 훨씬 덜 깨지도록 방어 로직이 들어갔습니다.
+
+### 3. `resolveNearestLowerOrEqualRepetition()`
+
+이 함수는 repetition 선택 규칙을 담당합니다.
+
+동작은 단순합니다.
+
+1. 새 repetition 목록에서 현재 repetition 이하인 값만 고릅니다.
+2. 그중 가장 큰 값을 선택합니다.
+3. 없다면 새 목록의 최소값을 사용합니다.
+
+이 함수가 추가되면서 `pulse duration` 또는 `fluence` 변경 시 repetition이 불필요하게 `1Hz`로 떨어지지 않게 되었습니다.
+
+## 함수별로 무엇이 바뀌었는가
+
+### 1. `updateHandPieceType()`
+
+핸드피스 종류를 바꾸면:
+
+- 해당 핸드피스에 맞는 테이블을 다시 불러오고
+- 기본 `pulseWidth`를 고른 뒤
+- 가능한 `fluence`를 정하고
+- 그에 맞는 `repetition` 목록을 계산합니다
+
+변경 전에는 반복수 목록을 직접 찾다가 실패 가능성이 있었고,
+변경 후에는 `resolveRepetitionContext()`를 통해 안전하게 계산합니다.
+
+또한 새 반복수 값도 목록의 첫 번째 값을 안전하게 가져오도록 바뀌었습니다.
+
+### 2. `updatePulseWidth()`
+
+펄스폭을 올리거나 내리면:
+
+- 새 `pulseWidth`에 맞는 `fluence`를 다시 정하고
+- 그 조합에 맞는 `repetition` 목록을 다시 계산합니다
+
+여기도 동일하게 공통 함수 사용으로 바뀌어,
+정확히 일치하는 값이 없을 때 현재 값 또는 가장 가까운 값으로 안전하게 처리합니다.
+
+추가로 repetition 선택 방식도 바뀌었습니다.
+
+- 예전: 새 repetition 목록의 첫 번째 값으로 사실상 초기화
+- 현재: 기존 repetition 이하에서 가장 가까운 최대값 선택
+
+예:
+
+- 기존 repetition = `10Hz`
+- 새 목록 = `1, 3, 5, 8`
+- 결과 = `8Hz`
+
+### 3. `updateFluence()`
+
+이 부분은 버그 수정이 포함되어 있어 중요합니다.
+
+기존 코드에는 주석으로도 남아 있듯이,
+원래 `fluence`를 업데이트해야 하는 상황에서 잘못된 필드를 갱신하던 문제가 있었습니다.
+
+수정 후에는:
+
+- `pulseWidth`에 맞는 `fluence` 목록에서 다음/이전 값을 고르고
+- 그 값으로 반복수 목록을 다시 계산한 뒤
+- repetition도 기존 값 이하에서 가장 가까운 최대값으로 다시 선택하고
+- 실제 프리셋에는 `fluence = repetitionContext.fluence`를 저장합니다
+
+즉, 사용자가 에너지 단계를 바꿨을 때 실제 프리셋 데이터도 올바르게 바뀌도록 고친 것입니다.
+이제 `fluence` 변경 시에도 repetition이 불필요하게 최소값으로 초기화되지 않습니다.
+
+### 4. `updateRepetition()`
+
+반복수만 변경할 때도 사실은 현재 `pulseWidth`와 `fluence`에 맞는 반복수 목록이 먼저 계산되어야 합니다.
+
+이번 수정 후에는:
+
+- 현재 조건에 맞는 반복수 목록을 공통 함수로 얻고
+- 그 목록 안에서 위/아래 이동을 수행하고
+- 필요하면 `fluence`도 보정된 값으로 같이 저장합니다
+
+이전 코드보다 현재 조건과 실제 목록이 더 일관되게 맞춰집니다.
+
+## 왜 이 수정이 필요한가
+
+이 코드는 여러 테이블을 조합해서 동작합니다.
+
+- `energyTable`: `(pulseWidth, fluence)` 조합에 대한 에너지 정보
+- `hzTable`: `(pulseWidth, fluence)` 조합에 대한 `hzType`
+- `RepetitionsByColorKey`: `hzType`에 따라 선택 가능한 반복수 목록
+
+문제는 사용자가 가진 값이 테이블의 키와 딱 맞지 않을 수 있다는 점입니다.
+
+예를 들어:
+
+- 현재 `pulseWidth`는 존재하지만
+- `fluence`가 소수점 차이로 정확히 일치하지 않거나
+- 핸드피스 변경 후 이전 값이 새 테이블에 없는 경우
+
+예전 코드는 이런 경우에 취약했습니다.
+이번 수정은 이런 경계 상황에서도 앱이 가능한 범위 안에서 계속 동작하도록 만든 것입니다.
+
+## 코틀린을 모르는 사람 기준으로 문법 설명
+
+### `fun`
+
+함수를 만든다는 뜻입니다.
+
+```kotlin
+fun updateFluence(...)
+```
+
+### `val`
+
+한 번 정하면 다시 바꾸지 않는 값입니다.
+
+```kotlin
+val newFluence = ...
+```
+
+### `data class`
+
+관련 있는 값 몇 개를 묶는 작은 자료형입니다.
+
+```kotlin
+data class ResolvedRepetitionContext(...)
+```
+
+### `copy(...)`
+
+기존 객체를 복사하면서 일부 값만 바꾸는 방식입니다.
+
+```kotlin
+currentList[index].copy(
+    fluence = repetitionContext.fluence,
+    repetition = newRepetition
+)
+```
+
+이 코드는 "기존 프리셋을 복사하되 `fluence`와 `repetition`만 새 값으로 바꾼다"는 뜻입니다.
+
+### `?:`
+
+왼쪽 값이 없으면 오른쪽 값을 대신 사용하라는 뜻입니다.
+
+```kotlin
+val newFluence = newFluenceList.firstOrNull() ?: currentList[index].fluence
+```
+
+즉:
+
+- 목록 첫 값이 있으면 그 값을 쓰고
+- 없으면 현재 저장된 `fluence`를 그대로 씁니다
+
+### `firstOrNull()`
+
+목록의 첫 번째 값을 가져오되, 비어 있으면 오류 대신 `null`을 돌려줍니다.
+
+안전한 코드에서 자주 쓰입니다.
+
+## 한 줄 요약
+
+이번 수정은 프리셋 편집 시 `pulseWidth`, `fluence`, `repetition`의 연결 계산을 더 안전하게 만들고, `pulse duration` 및 `fluence` 변경 시 repetition을 현재 값에 가장 가깝게 유지하도록 개선했으며, `fluence` 변경 시 잘못된 필드가 갱신되던 버그도 함께 바로잡은 변경입니다.

docs/serial_tx_startup_race.md

@@ -0,0 +1,41 @@
+# Serial TX Startup Race 정리
+
+## 1) FD(File Descriptor)란?
+- `FD`는 리눅스/안드로이드에서 열린 리소스(파일/소켓/시리얼 포트)를 가리키는 정수 핸들입니다.
+- 이 프로젝트에서 시리얼 포트 상태는 다음처럼 판단합니다.
+  - `FD == -1`: 포트 미오픈(유효하지 않음)
+  - `FD >= 0`: 포트 오픈 완료(유효)
+- 따라서 `FD == -1` 상태에서 `write()`를 호출하면 실제 시리얼 전송이 되지 않습니다.
+
+## 2) 문제 원인
+- `txPacketOnce()`가 앱 시작 직후 실행됩니다.
+- 시리얼 포트 `open()`은 `rxPacketLoop()` 내부에서 코루틴으로 비동기 시작됩니다.
+- 기존 순서에서 `txPacketOnce()`가 먼저 호출되면, 포트 오픈 완료 전(`FD == -1`)에 TX가 시도되어 초기 패킷 전송이 누락될 수 있습니다.
+
+## 3) 적용한 수정
+
+### A. 초기 호출 순서 조정
+- 파일: `app/src/main/java/com/laseroptek/raman/ui/MainActivity.kt`
+- 변경:
+  - 이전: `txPacketOnce()` -> `rxPacketLoop()` -> `txPacketLoop()`
+  - 이후: `rxPacketLoop()` -> `txPacketOnce()` -> `txPacketLoop()`
+- 목적: RX 루프가 먼저 포트 오픈을 시작하도록 해서 초기 TX 레이스 확률을 줄임
+
+### B. `txPacketOnce()`에 포트 준비 대기 추가
+- 파일: `app/src/main/java/com/laseroptek/raman/ui/screens/main/MainViewModel.kt`
+- 변경:
+  - `txPacketOnce()`를 IO 코루틴에서 실행
+  - `waitUntilSerialReady()`(최대 2초, 20ms 폴링)로 `FD != -1` 확인 후 TX 진행
+  - 시간 내 준비 실패 시 로그를 남기고 전송 중단
+- 목적: 순서만으로 보장되지 않는 코루틴 스케줄링 레이스를 방어
+
+## 4) 왜 TX에서 직접 open()하지 않았는가?
+- 현재 구조에서 `open()`의 데이터 콜백은 `rxPacketLoop()`의 `callbackFlow`와 연결됩니다.
+- TX 경로에서 별도 `open()`을 하면 중복 오픈/콜백 소유권/FD 교체 타이밍 이슈가 생길 수 있습니다.
+- 안정적인 패턴은:
+  - 포트 오픈 책임: RX(단일 지점)
+  - 포트 사용(TX): ready 확인 후 write
+
+## 5) 확인 포인트
+- 앱 시작 직후 로그에서 `FD`가 유효해진 뒤 `txPacketOnce()`의 TX 로그가 출력되는지 확인
+- 장비 측 시리얼 모니터에서 초기 패킷(Version/Q-Switch/GuideBeam/DCD/SprayDCD) 수신 여부 확인