feat(ui): trail — fixed 1 s sampling; drop GPS upd + Trail int from settings

GPS NMEA polling is cheap, and a slower cadence just hides motion from
the trail; the min-delta gate already filters jitter without throttling
the GPS. Both knobs that exposed cadence-style controls to the user are
removed:

- Trail sampling is fixed at TrailStore::SAMPLING_SECS = 1 s, matching
  the sensor manager's built-in GPS update default. The
  intervalSecs / intervalLabel / INTERVAL_COUNT helpers go with it.
- GPS update rate ("GPS upd" entry) leaves the sensor manager on its
  built-in 1 s default. applyGPSInterval and the GPS_INTERVAL_OPTS /
  LABELS tables / gpsIntervalIndex helper are deleted.

Both NodePrefs fields (gps_interval, trail_interval_idx) are retained
as reserved so the schema sentinel doesn't have to bump — older saves
load cleanly, the bytes are just ignored.

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

examples/companion_radio/NodePrefs.h

@@ -99,10 +99,10 @@ struct NodePrefs {  // persisted to file
   static const uint8_t FAVOURITE_PREFIX_LEN = 6;
   uint8_t favourite_contacts[FAVOURITES_COUNT][FAVOURITE_PREFIX_LEN];
 
-  // GPS trail cadence — indices into TrailStore::intervalSecs / minDeltaMeters.
-  // Logging on/off is a runtime state (Tools › Trail), not a persisted preference.
-  uint8_t trail_interval_idx;   // 0..3: 1min / 30s / 5min / 15min
-  uint8_t trail_min_delta_idx;  // 0..2: 25m / 5m / 100m
+  // GPS trail cadence. Logging on/off is a runtime state (Tools › Trail),
+  // not a persisted preference.
+  uint8_t trail_interval_idx;   // reserved — sampling cadence is now fixed at TrailStore::SAMPLING_SECS
+  uint8_t trail_min_delta_idx;  // indexes TrailStore::minDeltaMeters (5/10/25/100 m)
 
   // Tail sentinel written at the end of /new_prefs. Bump the low byte when
   // adding/removing/reordering fields in DataStore::savePrefs/loadPrefsInt so

examples/companion_radio/Trail.h

@@ -22,17 +22,11 @@ class TrailStore {
 public:
   static const int CAPACITY = 256;
 
-  // Interval options (seconds) and their settings labels. Index 0 default = 30 s,
-  // a reasonable middle for walking/cycling without burning GPS frames.
-  static const uint8_t INTERVAL_COUNT = 6;
-  static uint16_t intervalSecs(uint8_t idx) {
-    static const uint16_t OPTS[INTERVAL_COUNT] = { 30, 10, 20, 60, 300, 900 };
-    return OPTS[idx < INTERVAL_COUNT ? idx : 0];
-  }
-  static const char* intervalLabel(uint8_t idx) {
-    static const char* L[INTERVAL_COUNT] = { "30 s", "10 s", "20 s", "1 min", "5 min", "15 min" };
-    return L[idx < INTERVAL_COUNT ? idx : 0];
-  }
+  // Fixed sampling cadence — matches the sensor manager's default GPS update
+  // rate (1 s). Density is controlled by the min-delta gate (settings) rather
+  // than by throttling the GPS poll. The NodePrefs::trail_interval_idx field
+  // is retained as reserved for backwards compatibility but no longer used.
+  static const uint16_t SAMPLING_SECS = 1;
 
   // Min-delta (metres) gates samples too close to the previous one.
   // Default 5 m: keeps walking jitter out, dense enough for a visible trail.

examples/companion_radio/ui-new/SettingsScreen.h

@@ -59,8 +59,6 @@ class SettingsScreen : public UIScreen {
 #if ENV_INCLUDE_GPS == 1
     // GPS section
     SECTION_GPS,
-    GPS_INTERVAL,
-    TRAIL_INTERVAL,
     TRAIL_MIN_DELTA,
 #endif
     // Contacts section
@@ -82,11 +80,9 @@ class SettingsScreen : public UIScreen {
   static const char* AUTO_OFF_LABELS[5];
   static const int AUTO_OFF_COUNT = 5;
 #endif
-#if ENV_INCLUDE_GPS == 1
-  static const uint32_t GPS_INTERVAL_OPTS[6];
-  static const char* GPS_INTERVAL_LABELS[6];
-  static const int GPS_INTERVAL_COUNT = 6;
-#endif
+// GPS update interval tables are no longer surfaced in Settings — the sensor
+// manager defaults to 1 s when nothing else sets it. Pref byte _prefs.gps_interval
+// is retained for backwards compatibility.
   static const uint16_t LOW_BAT_OPTS[7];
   static const char* LOW_BAT_LABELS[7];
   static const int LOW_BAT_COUNT = 7;
@@ -130,15 +126,6 @@ class SettingsScreen : public UIScreen {
   }
 #endif
 
-#if ENV_INCLUDE_GPS == 1
-  int gpsIntervalIndex() {
-    NodePrefs* p = _task->getNodePrefs();
-    if (!p) return 0;
-    for (int i = 0; i < GPS_INTERVAL_COUNT; i++)
-      if (GPS_INTERVAL_OPTS[i] == p->gps_interval) return i;
-    return 0;
-  }
-#endif
 
   bool isSection(int item) const {
     return item == SECTION_DISPLAY || item == SECTION_SOUND ||
@@ -420,14 +407,6 @@ class SettingsScreen : public UIScreen {
       display.setCursor(display.valCol(), y);
       display.print((p && p->auto_lock) ? "ON" : "OFF");
 #if ENV_INCLUDE_GPS == 1
-    } else if (item == GPS_INTERVAL) {
-      display.print("GPS upd");
-      display.setCursor(display.valCol(), y);
-      display.print(GPS_INTERVAL_LABELS[gpsIntervalIndex()]);
-    } else if (item == TRAIL_INTERVAL) {
-      display.print("Trail int");
-      display.setCursor(display.valCol(), y);
-      display.print(TrailStore::intervalLabel(p ? p->trail_interval_idx : 0));
     } else if (item == TRAIL_MIN_DELTA) {
       display.print("Trail dist");
       display.setCursor(display.valCol(), y);
@@ -658,25 +637,6 @@ public:
       return true;
     }
 #if ENV_INCLUDE_GPS == 1
-    if (_selected == GPS_INTERVAL && p) {
-      int idx = gpsIntervalIndex();
-      if (right) idx = (idx + 1) % GPS_INTERVAL_COUNT;
-      if (left)  idx = (idx + GPS_INTERVAL_COUNT - 1) % GPS_INTERVAL_COUNT;
-      if (left || right) {
-        p->gps_interval = GPS_INTERVAL_OPTS[idx];
-        _task->applyGPSInterval();
-        _dirty = true;
-        return true;
-      }
-    }
-    if (_selected == TRAIL_INTERVAL && p && (left || right)) {
-      int idx = p->trail_interval_idx;
-      if (idx >= TrailStore::INTERVAL_COUNT) idx = 0;
-      idx = (idx + (right ? 1 : TrailStore::INTERVAL_COUNT - 1)) % TrailStore::INTERVAL_COUNT;
-      p->trail_interval_idx = (uint8_t)idx;
-      _dirty = true;
-      return true;
-    }
     if (_selected == TRAIL_MIN_DELTA && p && (left || right)) {
       int idx = p->trail_min_delta_idx;
       if (idx >= TrailStore::MIN_DELTA_COUNT) idx = 0;
@@ -771,10 +731,6 @@ public:
 const uint16_t SettingsScreen::AUTO_OFF_OPTS[5]   = { 5, 15, 30, 60, 0 };
 const char*    SettingsScreen::AUTO_OFF_LABELS[5]  = { "5s", "15s", "30s", "60s", "never" };
 #endif
-#if ENV_INCLUDE_GPS == 1
-const uint32_t SettingsScreen::GPS_INTERVAL_OPTS[6]  = { 0, 30, 60, 300, 900, 1800 };
-const char*    SettingsScreen::GPS_INTERVAL_LABELS[6] = { "off", "30s", "1min", "5min", "15min", "30min" };
-#endif
 const uint16_t SettingsScreen::LOW_BAT_OPTS[7]   = { 0, 3000, 3100, 3200, 3300, 3400, 3500 };
 const char*    SettingsScreen::LOW_BAT_LABELS[7]  = { "off", "3.0V", "3.1V", "3.2V", "3.3V", "3.4V", "3.5V" };
 const char*    SettingsScreen::BATT_DISPLAY_LABELS[3] = { "icon", "%", "V" };

examples/companion_radio/ui-new/UITask.cpp

@@ -1754,8 +1754,7 @@ void UITask::loop() {
   // fix; min-delta gate inside addPoint() avoids near-stationary spam.
   if (_trail.isActive() && _node_prefs != NULL
       && (int32_t)(millis() - _next_trail_sample_ms) >= 0) {
-    uint16_t interval_s = TrailStore::intervalSecs(_node_prefs->trail_interval_idx);
-    _next_trail_sample_ms = millis() + (uint32_t)interval_s * 1000UL;
+    _next_trail_sample_ms = millis() + (uint32_t)TrailStore::SAMPLING_SECS * 1000UL;
     LocationProvider* loc = _sensors ? _sensors->getLocationProvider() : nullptr;
     if (loc && loc->isValid()) {
       uint16_t md = TrailStore::minDeltaMeters(_node_prefs->trail_min_delta_idx);
@@ -1854,13 +1853,6 @@ void UITask::applyTxPower() {
   radio_set_tx_power(_node_prefs->tx_power_dbm);
 }
 
-void UITask::applyGPSInterval() {
-  if (_node_prefs == NULL) return;
-  char buf[12];
-  snprintf(buf, sizeof(buf),"%u", _node_prefs->gps_interval);
-  sensors.setSettingValue("gps_interval", buf);
-}
-
 void UITask::applyBrightness() {
   if (_display != NULL && _node_prefs != NULL) {
     _display->setBrightness(_node_prefs->display_brightness);

examples/companion_radio/ui-new/UITask.h

@@ -198,7 +198,6 @@ public:
   void setBuzzerVolumeLevel(uint8_t level);
   uint8_t getBuzzerVolume() const { return _node_prefs ? _node_prefs->buzzer_volume : 4; }
   void applyTxPower();
-  void applyGPSInterval();
   void applyFont();
   void applyRotation();
   void applyFullRefreshInterval();