App 2.16.1: Overview values every half second

The Overview read the car every 2 s, on the main thread. It now reads
every 0.5 s on a background thread (one reader; a read still running
makes the next tick skip rather than queue) and shows the values on the
main thread. The consumption and charging trackers stay on the 2-second
tick with the newest reading: they integrate over time, and the
charging tracker writes its session to storage on every sample.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki

SPECS.md

@@ -109,6 +109,11 @@ tyre pressures, GPS (lat, lon, elevation, heading) and the is_* flags. It does *
   INGEST_TOKEN) into git and pushed it. Commit amended and force-pushed; both values regenerated in
   the now gitignored `k8s/secrets.yaml` (since moved to `k8s/secrets/secrets.yaml`, outside
   `kubectl apply -f k8s/`). Filled-in secrets live only there from now on.
+- 2026-10-18 — App 2.16.1: the Overview reads the car every 0.5 s (was 2 s), on a background
+  thread; the consumption and charging trackers stay on the 2-second tick (they integrate over
+  time, and the charging tracker writes its session to storage on every sample). Note for
+  emulator tests: uiautomator can no longer dump the screen while the Overview is open, since
+  the UI is never idle.
 - 2026-10-18 — Grafana's read-only InfluxDB token without a manual step: an init container in
   the Grafana pod creates it with the admin token at every start, deletes the previous one and
   leaves only the read-only token in a memory volume; the datasource reads it with

app/build.gradle

@@ -34,8 +34,8 @@ android {
         applicationId "com.stinnesbeck.nilsmg4"
         minSdk 27
         targetSdk 36
-        versionCode 84
-        versionName "2.16.0"
+        versionCode 85
+        versionName "2.16.1"
 
         // Nothing about the server ships in the APK: its URL and ingest token are entered in
         // the app's Server tab (ServerConfig), and the database is only reachable by the server.

app/src/main/java/com/evsuite/abrp/MainActivity.java

@@ -87,6 +87,7 @@ public class MainActivity extends AppCompatActivity {
      * page shows what the car reports, whether or not the upload service is running, and a
      * signal the vehicle does not publish must show a dash rather than a zero.
      */
+    /** Used only on the overview-read thread. */
     private EnergyTelemetryReader vehicleReader;
     private TextView vehSoc, vehRange, vehPower, vehSpeed, vehOdometer,
             vehCharging, vehHvac,
@@ -214,7 +215,7 @@ public class MainActivity extends AppCompatActivity {
             refreshStatus();
             refreshCallLog();
             refreshSteeringKeys();
-            refreshVehicle();
+            sampleTrackers();
             refreshConsumption();
             refreshWifi();
             uiHandler.postDelayed(this, 2_000L);
@@ -330,6 +331,7 @@ public class MainActivity extends AppCompatActivity {
         super.onResume();
         // Poll state and log only while the screen is up; onPause cancels it.
         uiHandler.post(uiRefresh);
+        uiHandler.post(overviewRefresh);
     }
 
     @Override
@@ -376,6 +378,13 @@ public class MainActivity extends AppCompatActivity {
         super.onPause();
         // Stop polling off-screen: this activity has no reason to spend cycles then.
         uiHandler.removeCallbacks(uiRefresh);
+        uiHandler.removeCallbacks(overviewRefresh);
+    }
+
+    @Override
+    protected void onDestroy() {
+        carReader.shutdownNow();
+        super.onDestroy();
     }
 
     // ---------- Update check ----------
@@ -1315,16 +1324,73 @@ public class MainActivity extends AppCompatActivity {
      * is not work to repeat every two seconds. A read that throws leaves the cells as they
      * were rather than blanking the page — a transient miss is not news worth showing.
      */
-    private void refreshVehicle() {
+    // ---------- Overview: read every half second, off the main thread ----------
+
+    /** How often the Overview reads the car while it is on screen. */
+    private static final long OVERVIEW_REFRESH_MS = 500L;
+
+    /** One reader thread; a read that is still running makes the next tick skip, not queue. */
+    private final java.util.concurrent.ExecutorService carReader =
+            java.util.concurrent.Executors.newSingleThreadExecutor(r -> new Thread(r, "overview-read"));
+    private final java.util.concurrent.atomic.AtomicBoolean reading =
+            new java.util.concurrent.atomic.AtomicBoolean();
+    /** The newest reading, for the slower work on the 2-second tick. */
+    private volatile EnergySnapshot latestSnapshot;
+
+    private final Runnable overviewRefresh = new Runnable() {
+        @Override public void run() {
+            readVehicle();
+            uiHandler.postDelayed(this, OVERVIEW_REFRESH_MS);
+        }
+    };
+
+    /**
+     * About twenty calls into the car's services: on a background thread, so the screen never
+     * waits for them; the values are shown on the main thread once they are in.
+     */
+    private void readVehicle() {
+        if (!reading.compareAndSet(false, true)) return;
+        try {
+            carReader.execute(() -> {
+                try {
+                    if (vehicleReader == null) {
+                        vehicleReader = new EnergyTelemetryReader(getApplicationContext());
+                    }
+                    // The timestamp is passed explicitly: its Kotlin default is not visible from Java.
+                    EnergySnapshot s = vehicleReader.read(System.currentTimeMillis());
+                    latestSnapshot = s;
+                    runOnUiThread(() -> {
+                        if (!isDestroyed()) showVehicle(s);
+                    });
+                } catch (Throwable ignored) {
+                    // Leave the last good reading on screen.
+                } finally {
+                    reading.set(false);
+                }
+            });
+        } catch (java.util.concurrent.RejectedExecutionException e) {
+            reading.set(false); // the activity is going away
+        }
+    }
+
+    /**
+     * The consumption and charging trackers stay on the 2-second tick: they integrate over
+     * time, so a faster rate adds nothing, and the charging tracker writes its session to
+     * storage on every sample while charging.
+     */
+    private void sampleTrackers() {
+        EnergySnapshot s = latestSnapshot;
+        if (s == null) return;
         try {
-            if (vehicleReader == null) {
-                vehicleReader = new EnergyTelemetryReader(getApplicationContext());
-            }
-            // The timestamp is passed explicitly: its Kotlin default is not visible from Java.
-            EnergySnapshot s = vehicleReader.read(System.currentTimeMillis());
             ConsumptionTracker.get(this).sample(s);
             refreshCharging(s);
+        } catch (Throwable ignored) {
+            // A tracker failure must not stop the page.
+        }
+    }
 
+    private void showVehicle(EnergySnapshot s) {
+        try {
             vehSoc.setText(fmt(s.getSocPercent(), "%.0f %%"));
             vehRange.setText(fmt(s.getRangeKm(), "%.0f km"));
             vehPower.setText(fmt(s.getBatteryPowerKw(), "%.1f kW"));