feat(instruments): replace simulation with real GPS and barometer data

- Drop VMG, Polar %, and PolarDiagramView — no NMEA source on boat
- Shrink grid to 3×2 (AWS/HDG/BSP / TWS/COG/SOG)
- Move Depth + Baro to expanded section side by side
- Initialize all instruments to "—" on startup
- Wire LocationService.locationFlow → SOG + COG display (real GPS)
- Wire LocationService.barometerStatus → Baro display (device sensor)
- Delete startInstrumentSimulation() fake loop entirely

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

3 files changed, 51 insertions, 142 deletions

diff --git a/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt b/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt
index 252761e..c48cec2 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt
@@ -11,7 +11,6 @@ import android.os.Bundle
 import android.util.Log
 import android.view.View
 import android.widget.FrameLayout
-import android.widget.Toast
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
@@ -22,15 +21,12 @@ import com.google.android.material.bottomnavigation.BottomNavigationView
 import com.google.android.material.button.MaterialButton
 import com.google.android.material.bottomsheet.BottomSheetBehavior
 import com.google.android.material.floatingactionbutton.FloatingActionButton
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.firstOrNull
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.withContext
+import java.util.Locale
 import org.maplibre.android.MapLibre
 import org.maplibre.android.maps.MapView
 import org.maplibre.android.maps.Style
@@ -185,20 +181,14 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
             valueCog = findViewById(R.id.value_cog),
             valueBsp = findViewById(R.id.value_bsp),
             valueSog = findViewById(R.id.value_sog),
-            valueVmg = findViewById(R.id.value_vmg),
             valueDepth = findViewById(R.id.value_depth),
-            valuePolarPct = findViewById(R.id.value_polar_pct),
-            valueBaro = findViewById(R.id.value_baro),
-            labelTrend = null, // simplified
-            barometerTrendView = null, // simplified
-            polarDiagramView = findViewById(R.id.polar_diagram_view)
+            valueBaro = findViewById(R.id.value_baro)
+        )
+        instrumentHandler?.updateDisplay(
+            aws = "—", tws = "—", hdg = "—",
+            cog = "—", bsp = "—", sog = "—",
+            depth = "—", baro = "—"
         )
-        
-        // anchorWatchHandler is initialized when the anchor config UI is available
-
-        val mockPolarTable = createMockPolarTable()
-        findViewById<PolarDiagramView>(R.id.polar_diagram_view).setPolarTable(mockPolarTable)
-        startInstrumentSimulation(mockPolarTable)
     }
 
     // Helper to convert dp to px
@@ -277,7 +267,19 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
             LocationService.locationFlow.collect { gpsData ->
                 mapHandler?.centerOnLocation(gpsData.latitude, gpsData.longitude)
                 val sogKnots = gpsData.speedOverGround * 1.94384
-                viewModel.addGpsPoint(gpsData.latitude, gpsData.longitude, sogKnots, gpsData.courseOverGround.toDouble())
+                val cogDeg = gpsData.courseOverGround
+                viewModel.addGpsPoint(gpsData.latitude, gpsData.longitude, sogKnots, cogDeg.toDouble())
+                instrumentHandler?.updateDisplay(
+                    sog = "%.1f".format(Locale.getDefault(), sogKnots),
+                    cog = "%.0f°".format(Locale.getDefault(), cogDeg)
+                )
+            }
+        }
+        lifecycleScope.launch {
+            LocationService.barometerStatus.collect { status ->
+                if (status.history.isNotEmpty()) {
+                    instrumentHandler?.updateDisplay(baro = status.formatPressure())
+                }
             }
         }
         lifecycleScope.launch {
@@ -292,28 +294,6 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
         }
     }
 
-    private fun startInstrumentSimulation(polarTable: PolarTable) {
-        lifecycleScope.launch {
-            var simulatedTws = 8.0
-            var simulatedTwa = 40.0
-            while (true) {
-                val bsp = polarTable.interpolateBsp(simulatedTws, simulatedTwa)
-                instrumentHandler?.updateDisplay(
-                    aws = "%.1f".format(Locale.getDefault(), simulatedTws * 1.1),
-                    tws = "%.1f".format(Locale.getDefault(), simulatedTws),
-                    bsp = "%.1f".format(Locale.getDefault(), bsp),
-                    sog = "%.1f".format(Locale.getDefault(), bsp * 0.95),
-                    vmg = "%.1f".format(Locale.getDefault(), polarTable.curves.firstOrNull { it.twS == simulatedTws }?.calculateVmg(simulatedTwa, bsp) ?: 0.0),
-                    polarPct = "%.0f%%".format(Locale.getDefault(), polarTable.calculatePolarPercentage(simulatedTws, simulatedTwa, bsp)),
-                    baro = "1013.2"
-                )
-                instrumentHandler?.updatePolarDiagram(simulatedTws, simulatedTwa, bsp)
-                simulatedTwa = (simulatedTwa + 0.5).let { if (it > 170) 40.0 else it }
-                delay(1000)
-            }
-        }
-    }
-
     private fun rasterizeDrawable(drawableId: Int): Bitmap {
         val drawable = ContextCompat.getDrawable(this, drawableId)!!
         val bitmap = Bitmap.createBitmap(drawable.intrinsicWidth, drawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
@@ -323,15 +303,6 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
         return bitmap
     }
 
-    private fun createMockPolarTable(): PolarTable {
-        val curves = listOf(6.0, 8.0, 10.0).map { tws ->
-            PolarCurve(tws, listOf(30.0, 45.0, 60.0, 90.0, 120.0, 150.0, 180.0).map { twa ->
-                PolarPoint(twa, tws * (0.4 + twa / 200.0))
-            })
-        }
-        return PolarTable(curves)
-    }
-
     private fun fadeOut(vararg views: View, gone: Boolean = false) {
         views.forEach { v ->
             v.animate().alpha(0f).setDuration(150).withEndAction {
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/ui/InstrumentHandler.kt b/android-app/app/src/main/kotlin/org/terst/nav/ui/InstrumentHandler.kt
index 2f72153..7e09756 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/ui/InstrumentHandler.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/ui/InstrumentHandler.kt
@@ -1,11 +1,6 @@
 package org.terst.nav.ui
 
 import android.widget.TextView
-import org.terst.nav.BarometerReading
-import org.terst.nav.BarometerTrendView
-import org.terst.nav.PolarDiagramView
-import org.terst.nav.R
-import java.util.Locale
 
 /**
  * Handles the display of instrument data in the UI.
@@ -17,16 +12,11 @@ class InstrumentHandler(
     private val valueCog: TextView,
     private val valueBsp: TextView,
     private val valueSog: TextView,
-    private val valueVmg: TextView,
     private val valueDepth: TextView,
-    private val valuePolarPct: TextView,
-    private val valueBaro: TextView,
-    private val labelTrend: TextView?,
-    private val barometerTrendView: BarometerTrendView?,
-    private val polarDiagramView: PolarDiagramView
+    private val valueBaro: TextView
 ) {
     /**
-     * Updates the text displays for various instruments.
+     * Updates the text displays for the given instruments. Null arguments leave the current value unchanged.
      */
     fun updateDisplay(
         aws: String? = null,
@@ -35,11 +25,8 @@ class InstrumentHandler(
         cog: String? = null,
         bsp: String? = null,
         sog: String? = null,
-        vmg: String? = null,
         depth: String? = null,
-        polarPct: String? = null,
-        baro: String? = null,
-        trend: String? = null
+        baro: String? = null
     ) {
         aws?.let { valueAws.text = it }
         tws?.let { valueTws.text = it }
@@ -47,24 +34,7 @@ class InstrumentHandler(
         cog?.let { valueCog.text = it }
         bsp?.let { valueBsp.text = it }
         sog?.let { valueSog.text = it }
-        vmg?.let { valueVmg.text = it }
         depth?.let { valueDepth.text = it }
-        polarPct?.let { valuePolarPct.text = it }
         baro?.let { valueBaro.text = it }
-        trend?.let { labelTrend?.text = it }
-    }
-
-    /**
-     * Updates the polar diagram view.
-     */
-    fun updatePolarDiagram(tws: Double, twa: Double, bsp: Double) {
-        polarDiagramView.setCurrentPerformance(tws, twa, bsp)
-    }
-
-    /**
-     * Updates the barometer trend chart.
-     */
-    fun updateBarometerTrend(history: List<BarometerReading>) {
-        barometerTrendView?.setHistory(history)
     }
 }
diff --git a/android-app/app/src/main/res/layout/layout_instruments_sheet.xml b/android-app/app/src/main/res/layout/layout_instruments_sheet.xml
index 0a84418..c651ba2 100644
--- a/android-app/app/src/main/res/layout/layout_instruments_sheet.xml
+++ b/android-app/app/src/main/res/layout/layout_instruments_sheet.xml
@@ -16,14 +16,14 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent" />
 
-    <!-- Grid of Instruments -->
+    <!-- 3×2 grid: AWS/HDG/BSP top row, TWS/COG/SOG bottom row -->
     <androidx.gridlayout.widget.GridLayout
         android:id="@+id/instrument_grid"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         app:columnCount="3"
-        app:rowCount="3"
+        app:rowCount="2"
         app:layout_constraintTop_toBottomOf="@id/drag_handle">
 
         <!-- Wind: AWS -->
@@ -35,7 +35,7 @@
             android:gravity="center"
             android:padding="8dp">
             <TextView style="@style/InstrumentLabel" android:text="AWS" />
-            <TextView android:id="@+id/value_aws" style="@style/InstrumentPrimaryValue" tools:text="12.5" />
+            <TextView android:id="@+id/value_aws" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
         <!-- Compass: HDG -->
@@ -47,7 +47,7 @@
             android:gravity="center"
             android:padding="8dp">
             <TextView style="@style/InstrumentLabel" android:text="HDG" />
-            <TextView android:id="@+id/value_hdg" style="@style/InstrumentPrimaryValue" tools:text="225" />
+            <TextView android:id="@+id/value_hdg" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
         <!-- Performance: BSP -->
@@ -59,7 +59,7 @@
             android:gravity="center"
             android:padding="8dp">
             <TextView style="@style/InstrumentLabel" android:text="BSP" />
-            <TextView android:id="@+id/value_bsp" style="@style/InstrumentPrimaryValue" tools:text="6.2" />
+            <TextView android:id="@+id/value_bsp" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
         <!-- Wind: TWS -->
@@ -71,7 +71,7 @@
             android:gravity="center"
             android:padding="8dp">
             <TextView style="@style/InstrumentLabel" android:text="TWS" />
-            <TextView android:id="@+id/value_tws" style="@style/InstrumentPrimaryValue" tools:text="15.0" />
+            <TextView android:id="@+id/value_tws" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
         <!-- Compass: COG -->
@@ -83,7 +83,7 @@
             android:gravity="center"
             android:padding="8dp">
             <TextView style="@style/InstrumentLabel" android:text="COG" />
-            <TextView android:id="@+id/value_cog" style="@style/InstrumentPrimaryValue" tools:text="230" />
+            <TextView android:id="@+id/value_cog" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
         <!-- Performance: SOG -->
@@ -95,72 +95,40 @@
             android:gravity="center"
             android:padding="8dp">
             <TextView style="@style/InstrumentLabel" android:text="SOG" />
-            <TextView android:id="@+id/value_sog" style="@style/InstrumentPrimaryValue" tools:text="6.5" />
+            <TextView android:id="@+id/value_sog" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
-        <!-- VMG -->
-        <LinearLayout
-            android:layout_width="0dp"
-            android:layout_height="wrap_content"
-            app:layout_columnWeight="1"
-            android:orientation="vertical"
-            android:gravity="center"
-            android:padding="8dp">
-            <TextView style="@style/InstrumentLabel" android:text="VMG" />
-            <TextView android:id="@+id/value_vmg" style="@style/InstrumentPrimaryValue" tools:text="4.2" />
-        </LinearLayout>
+    </androidx.gridlayout.widget.GridLayout>
+
+    <!-- Expanded: Depth + Baro side by side -->
+    <LinearLayout
+        android:id="@+id/expanded_instruments"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:layout_marginTop="24dp"
+        app:layout_constraintTop_toBottomOf="@id/instrument_grid"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent">
 
-        <!-- Depth -->
         <LinearLayout
             android:layout_width="0dp"
             android:layout_height="wrap_content"
-            app:layout_columnWeight="1"
-            android:orientation="vertical"
-            android:gravity="center"
-            android:padding="8dp">
+            android:layout_weight="1"
+            android:orientation="vertical">
             <TextView style="@style/InstrumentLabel" android:text="Depth" />
-            <TextView android:id="@+id/value_depth" style="@style/InstrumentPrimaryValue" tools:text="12.0" />
+            <TextView android:id="@+id/value_depth" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
-        <!-- Polar % -->
         <LinearLayout
             android:layout_width="0dp"
             android:layout_height="wrap_content"
-            app:layout_columnWeight="1"
-            android:orientation="vertical"
-            android:gravity="center"
-            android:padding="8dp">
-            <TextView style="@style/InstrumentLabel" android:text="Polar %" />
-            <TextView android:id="@+id/value_polar_pct" style="@style/InstrumentPrimaryValue" tools:text="95%" />
+            android:layout_weight="1"
+            android:orientation="vertical">
+            <TextView style="@style/InstrumentLabel" android:text="Baro" />
+            <TextView android:id="@+id/value_baro" style="@style/InstrumentPrimaryValue" tools:text="—" />
         </LinearLayout>
 
-    </androidx.gridlayout.widget.GridLayout>
-
-    <!-- Additional Detail (Visible when expanded) -->
-    <TextView
-        android:id="@+id/label_baro"
-        style="@style/InstrumentLabel"
-        android:text="Barometer"
-        android:layout_marginTop="24dp"
-        app:layout_constraintTop_toBottomOf="@id/instrument_grid"
-        app:layout_constraintStart_toStartOf="parent" />
-
-    <TextView
-        android:id="@+id/value_baro"
-        style="@style/InstrumentPrimaryValue"
-        tools:text="1013.2 hPa"
-        app:layout_constraintTop_toBottomOf="@id/label_baro"
-        app:layout_constraintStart_toStartOf="parent" />
-
-    <org.terst.nav.PolarDiagramView
-        android:id="@+id/polar_diagram_view"
-        android:layout_width="0dp"
-        android:layout_height="0dp"
-        android:layout_marginTop="24dp"
-        app:layout_constraintDimensionRatio="1:1"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintTop_toBottomOf="@id/value_baro"
-        app:layout_constraintBottom_toBottomOf="parent" />
+    </LinearLayout>
 
 </androidx.constraintlayout.widget.ConstraintLayout>