From 23caa11f517013efca806695424a5b4de65bc7cd Mon Sep 17 00:00:00 2001
From: Jakub <106778416+MarekZegare4@users.noreply.github.com>
Date: Sun, 27 Sep 2026 00:12:08 +0200
Subject: [PATCH] feat(ui-lvgl): power saving, review fixes, shared helpers

Power: the UI loop sleeps until something is due (never with packets
queued); screen off puts the CPU at 80 MHz, the GT911 to sleep (unless a
tap wakes the screen) and the LP5814 in standby. GPS off now cuts the
L76K's rail and UART on the L2 (L2GpsProvider). The battery divider is
powered only for a reading (measured: settles at once); readings within
2 s are reused. The SD mount is retried at most every 5 s.

Fixes: WiFi left on after leaving a scan, live tiles' WiFi kept with the
screen off on the map, an ADC read every second for the status bar, touch
polled on every pass while dark, a scan cutting an update's WiFi, relay
count not refreshing in a channel thread, raw @[nick] in room previews.
Labels skip unchanged text (no redraw).

Helpers: scrollList, dimOverlay, settingRow, flexBox, nvs::get/put,
trailFilePath (a second save in the same minute no longer overwrites),
unreadTotal. Dead code removed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 docs/development/l2-roadmap.md                |  10 +-
 .../companion_radio/ui-lvgl/AdminScreen.h     |   8 +-
 examples/companion_radio/ui-lvgl/BotScreen.h  |  10 +-
 .../companion_radio/ui-lvgl/ChannelScreen.h   |   8 +-
 .../ui-lvgl/ConversationScreen.h              |   4 +-
 .../companion_radio/ui-lvgl/DeviceScreen.h    |   9 +-
 examples/companion_radio/ui-lvgl/DiagScreen.h |   2 +-
 .../companion_radio/ui-lvgl/HistoryStore.h    |   3 +-
 examples/companion_radio/ui-lvgl/LvglPort.h   | 178 ++++++---------
 examples/companion_radio/ui-lvgl/MapScreen.h  |  13 +-
 examples/companion_radio/ui-lvgl/NavMap.h     |  82 +++----
 examples/companion_radio/ui-lvgl/OtaScreen.h  |   3 +
 .../companion_radio/ui-lvgl/RadioScreen.h     |  22 +-
 .../companion_radio/ui-lvgl/RepeaterScreen.h  |   1 -
 .../companion_radio/ui-lvgl/SoundScreen.h     |   2 +-
 examples/companion_radio/ui-lvgl/UITask.cpp   | 205 +++++++++---------
 examples/companion_radio/ui-lvgl/UITask.h     |  10 +-
 examples/companion_radio/ui-lvgl/WifiScreen.h |   2 +-
 variants/wio-tracker-l2/WioTrackerL2Board.cpp |  34 ++-
 variants/wio-tracker-l2/WioTrackerL2Board.h   |  14 +-
 variants/wio-tracker-l2/WioTrackerL2Display.h |  25 ++-
 variants/wio-tracker-l2/target.cpp            |  24 +-
 variants/wio-tracker-l2/target.h              |  15 +-
 23 files changed, 337 insertions(+), 347 deletions(-)

diff --git a/docs/development/l2-roadmap.md b/docs/development/l2-roadmap.md
index d85eb9dc..e7dc5350 100644
--- a/docs/development/l2-roadmap.md
+++ b/docs/development/l2-roadmap.md
@@ -226,7 +226,15 @@ Ideas to come back to (2026-09-26):
 - [ ] Speaker click: would keeping the amplifier on at minimum volume
       remove it?
 - [ ] Import routes from the SD card (optional extra).
-- [ ] Battery life without losing features, above all CPU sleep.
+- [x] Battery life without losing features (2026-09-27): the UI loop sleeps
+      until something is due (none while packets are queued; 1-2 ms with a
+      melody / the app connected; up to 10 ms awake, 20 ms dark); screen off:
+      CPU at 80 MHz, touch controller asleep unless it wakes the screen,
+      backlight driver in standby. GPS off really cuts the L76K's rail (and
+      its UART). Battery divider powered only for a reading (measured: settles
+      at once). Also fixed: WiFi left on after a scan cut short, live tiles'
+      WiFi kept with the screen off on the map, a battery ADC read every
+      second. Not measured yet: the current before / after.
 - [x] Live tiles: bounded cache on the card (2026-09-26) -- they go to
       /sdcard/maps-live, apart from downloaded maps; an index keeps their
       order and the oldest are deleted past the limit (Settings > Storage >
diff --git a/examples/companion_radio/ui-lvgl/AdminScreen.h b/examples/companion_radio/ui-lvgl/AdminScreen.h
index e90c7ca1..bd0ef886 100644
--- a/examples/companion_radio/ui-lvgl/AdminScreen.h
+++ b/examples/companion_radio/ui-lvgl/AdminScreen.h
@@ -165,13 +165,7 @@ void UITask::buildAdmin() {
   lv_obj_add_event_cb(s_status, onAdminCancelWait, LV_EVENT_CLICKED, NULL);
   lv_obj_add_flag(s_status, LV_OBJ_FLAG_HIDDEN);
 
-  s_list = lv_obj_create(body);
-  styleSurface(s_list, theme::BG);
-  lv_obj_set_width(s_list, LV_PCT(100));
-  lv_obj_set_flex_grow(s_list, 1);
-  lv_obj_set_flex_flow(s_list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(s_list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(s_list, LV_SCROLLBAR_MODE_ACTIVE);
+  s_list = scrollList(body);
   for (int i = 0; i < admin::rowCount(s_tab); i++) {
     const admin::Field& f = admin::field(s_tab, i);
     const char* hint = f.isCustom() ? "Any CLI command" : f.isAction() ? nullptr
diff --git a/examples/companion_radio/ui-lvgl/BotScreen.h b/examples/companion_radio/ui-lvgl/BotScreen.h
index dcd20a92..9b4640a9 100644
--- a/examples/companion_radio/ui-lvgl/BotScreen.h
+++ b/examples/companion_radio/ui-lvgl/BotScreen.h
@@ -89,18 +89,12 @@ void UITask::buildBot() {
   lv_obj_set_style_bg_color(tabs, lv_color_hex(theme::SURFACE), LV_PART_ITEMS);
   lv_obj_add_event_cb(tabs, onBotTab, LV_EVENT_VALUE_CHANGED, NULL);
 
-  lv_obj_t* list = lv_obj_create(body);
-  styleSurface(list, theme::BG);
-  lv_obj_set_width(list, LV_PCT(100));
-  lv_obj_set_flex_grow(list, 1);
-  lv_obj_set_flex_flow(list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(list, LV_SCROLLBAR_MODE_ACTIVE);
+  lv_obj_t* list = scrollList(body);
 
   for (int i = 0; i < botcfg::rowCount(s_tab); i++) {
     const botcfg::Row& r = botcfg::row(s_tab, i);
     uint8_t* fl = botcfg::flag(p, r.kind);
-    lv_obj_t* row = radioview::settingRow(list, r.label, fl || botcfg::isHour(r.kind) ? r.hint : nullptr);
+    lv_obj_t* row = settingRow(list, r.label, fl || botcfg::isHour(r.kind) ? r.hint : nullptr);
     if (fl && r.kind == botcfg::DM_SCOPE) {
       static const char* SCOPE[] = { "All", "Fav", "" };
       lv_obj_t* seg = segmented(row, SCOPE, *fl ? 1 : 0, 110, 32);
diff --git a/examples/companion_radio/ui-lvgl/ChannelScreen.h b/examples/companion_radio/ui-lvgl/ChannelScreen.h
index 99752c17..d1cb9223 100644
--- a/examples/companion_radio/ui-lvgl/ChannelScreen.h
+++ b/examples/companion_radio/ui-lvgl/ChannelScreen.h
@@ -83,13 +83,13 @@ void UITask::channelMenu(int idx) {
   // bottom of the screen from a popup this low).
   static const char* NOTIF[] = { "Default", "Muted", "Always", "" };
   static const char* MELODY[] = { "Default", "Melody 1", "Melody 2", "" };
-  lv_obj_t* row = radioview::settingRow(panel, "Alerts", NULL);
+  lv_obj_t* row = settingRow(panel, "Alerts", NULL);
   radioview::rowSegmented(row, NOTIF, chanctl::notif(_prefs, idx), 200, onChanSegment, C_NOTIF);
-  row = radioview::settingRow(panel, "Sound", NULL);
+  row = settingRow(panel, "Sound", NULL);
   radioview::rowSegmented(row, MELODY, chanctl::melody(_prefs, idx), 200, onChanSegment, C_MELODY);
   const ScopeList& sl = the_mesh.scopeList();
   if (sl.count > 0) {   // only once regions are set up (Settings in the app)
-    row = radioview::settingRow(panel, "Scope", "Region it's sent in");
+    row = settingRow(panel, "Scope", "Region it's sent in");
     int o = 0;
     for (uint8_t i = 0; i <= sl.count && o < (int)sizeof(s_scope_opts) - 24; i++)
       o += snprintf(s_scope_opts + o, sizeof(s_scope_opts) - o, "%s%s", i ? "\n" : "", sl.name(i));
@@ -217,7 +217,7 @@ void UITask::buildChannelEdit() {
   s_secret = chanField(body, "Passphrase");
   lv_textarea_set_max_length(s_secret, 32);
 
-  lv_obj_t* row = radioview::settingRow(body, "Hex key", "32 characters");
+  lv_obj_t* row = settingRow(body, "Hex key", "32 characters");
   s_hex_sw = lv_switch_create(row);
   lv_obj_set_size(s_hex_sw, 46, 24);
   lv_obj_align(s_hex_sw, LV_ALIGN_RIGHT_MID, -theme::PAD, 0);
diff --git a/examples/companion_radio/ui-lvgl/ConversationScreen.h b/examples/companion_radio/ui-lvgl/ConversationScreen.h
index a187bae2..cc61c6d6 100644
--- a/examples/companion_radio/ui-lvgl/ConversationScreen.h
+++ b/examples/companion_radio/ui-lvgl/ConversationScreen.h
@@ -163,10 +163,10 @@ void UITask::conversationMenu(const uint8_t* pub_key) {
 
   if (!room) {   // alerts: three segments (a dropdown's list runs off screen this low)
     static const char* NOTIF[] = { "Default", "Muted", "Always", "" };
-    lv_obj_t* row = radioview::settingRow(panel, "Alerts", NULL);
+    lv_obj_t* row = settingRow(panel, "Alerts", NULL);
     radioview::rowSegmented(row, NOTIF, contactctl::notif(_prefs, ci.id.pub_key), 200, onConvNotif, 0);
     static const char* MELODY[] = { "Default", "Melody 1", "Melody 2", "" };
-    row = radioview::settingRow(panel, "Sound", NULL);
+    row = settingRow(panel, "Sound", NULL);
     radioview::rowSegmented(row, MELODY, contactctl::melody(_prefs, ci.id.pub_key), 200, onConvMelody, 0);
   } else {
     bool in = _core->rooms.isLoggedIn(ci.id.pub_key);
diff --git a/examples/companion_radio/ui-lvgl/DeviceScreen.h b/examples/companion_radio/ui-lvgl/DeviceScreen.h
index f94d9ded..17e188c3 100644
--- a/examples/companion_radio/ui-lvgl/DeviceScreen.h
+++ b/examples/companion_radio/ui-lvgl/DeviceScreen.h
@@ -248,7 +248,7 @@ void UITask::unlockScreen() {
     anim::run(fading, anim::setBgOpa, LV_OPA_COVER, LV_OPA_TRANSP, anim::UNLOCK_MS, anim::coverDone);
     if (_body) anim::run(_body, anim::setTy, 12, 0, anim::UNLOCK_MS);
   }
-  s_lock =s_lock_clock = s_lock_date = s_lock_unread = s_lock_slider = s_pin_dots = s_pin_msg = nullptr;
+  s_lock = s_lock_clock = s_lock_date = s_lock_unread = s_lock_slider = s_pin_dots = s_pin_msg = nullptr;
   _pin_entry[0] = '\0';
   if (_screen == SCR_HOME) refreshHome();
   else if (_screen == SCR_CHATS) buildChats();   // counts moved on while locked
@@ -302,7 +302,7 @@ void UITask::refreshLock() {
     lv_label_set_text(s_lock_clock, clk);
     if (s_lock_date) lv_label_set_text(s_lock_date, date);
   }
-  int unread = _core->dmUnreadTotal() + _core->history.getTotalChannelUnread() + _core->roomUnread();
+  int unread = unreadTotal();
   if (!s_lock_date) {   // PIN card: the count next to the clock, the keypad's line
     if (unread > 0) lv_label_set_text_fmt(s_lock_unread, LV_SYMBOL_ENVELOPE " %d", unread);
     else lv_label_set_text(s_lock_unread, "");
@@ -449,11 +449,6 @@ void UITask::setAccent(int idx) {
 
 // ── Favourites card (Home, left of the main page) ─────────────────────────────
 
-void UITask::showFavourites() {
-  home::s_page = home::FAVS;
-  showHome();
-}
-
 // The six slots, three to a row, into `grid` (a wrapping row).
 void UITask::favGrid(lv_obj_t* grid) {
   int w = (lv_display_get_horizontal_resolution(NULL) - 2 * theme::PAD - 2 * theme::GAP) / 3;
diff --git a/examples/companion_radio/ui-lvgl/DiagScreen.h b/examples/companion_radio/ui-lvgl/DiagScreen.h
index beec19e7..5a7a4b6c 100644
--- a/examples/companion_radio/ui-lvgl/DiagScreen.h
+++ b/examples/companion_radio/ui-lvgl/DiagScreen.h
@@ -117,7 +117,7 @@ void UITask::refreshDiag() {
   int n = allRows(rows, _core->gpsEnabled());
   if (n != s_rows) { buildDiag(); return; }
   for (int i = 0; i < n; i++)
-    if (strcmp(lv_label_get_text(s_vals[i]), rows[i].value) != 0) lv_label_set_text(s_vals[i], rows[i].value);
+    lv_label_set_text(s_vals[i], rows[i].value);   // unchanged text isn't redrawn (UITask.cpp)
 }
 
 void UITask::diagResetPopup() {
diff --git a/examples/companion_radio/ui-lvgl/HistoryStore.h b/examples/companion_radio/ui-lvgl/HistoryStore.h
index 47659810..c6c87537 100644
--- a/examples/companion_radio/ui-lvgl/HistoryStore.h
+++ b/examples/companion_radio/ui-lvgl/HistoryStore.h
@@ -245,8 +245,7 @@ private:
     snprintf(tmp, sizeof(tmp), "%s.tmp", path);
     FILE* o = fopen(tmp, "wb");
     if (o) {
-      Hdr nh = { MAGIC, VERSION, (uint16_t)sizeof(E), cap, 0, got, h.next_id };
-      nh.next_id = h.next_id;   // ids of the kept records stay as they were
+      Hdr nh = { MAGIC, VERSION, (uint16_t)sizeof(E), cap, 0, got, h.next_id };   // the kept records keep their ids
       bool ok = fwrite(&nh, sizeof(nh), 1, o) == 1 && (got == 0 || fwrite(buf, sizeof(E), got, o) == got);
       fclose(o);
       if (ok) { remove(path); rename(tmp, path); }   // FAT's rename doesn't replace
diff --git a/examples/companion_radio/ui-lvgl/LvglPort.h b/examples/companion_radio/ui-lvgl/LvglPort.h
index 90660d4c..a161e0d3 100644
--- a/examples/companion_radio/ui-lvgl/LvglPort.h
+++ b/examples/companion_radio/ui-lvgl/LvglPort.h
@@ -103,6 +103,21 @@ static bool touched() {
 
 static void swallowTouch() { s_swallow = true; }
 
+// ── Power ────────────────────────────────────────────────────────────────────
+// Screen off: the CPU clock down (LoRa, BLE and WiFi all run at 80 MHz) and
+// the touch panel asleep unless a tap is to wake the screen. Screen on: back.
+static bool s_touch_asleep = false;
+static void powerSave(bool on, bool keep_touch) {
+  static uint32_t full_mhz = 0;
+  if (!full_mhz) full_mhz = getCpuFrequencyMhz();
+  setCpuFrequencyMhz(on ? 80 : full_mhz);
+  if (on && !keep_touch) { board.touchSleep(); s_touch_asleep = true; }
+  else if (!on && s_touch_asleep) { board.touchWake(); s_touch_asleep = false; }
+}
+// Nothing due for `ms`: the loop task blocks and the core idles, clock-gated,
+// instead of spinning.
+static void idle(uint32_t ms) { if (ms) vTaskDelay(pdMS_TO_TICKS(ms)); }
+
 // Backlight 1-100 % (the brightness slider), on the LP5814 PWM.
 static void setBacklightPct(uint8_t pct) {
   if (pct > 100) pct = 100;
@@ -110,141 +125,84 @@ static void setBacklightPct(uint8_t pct) {
 }
 
 // microSD over SDMMC, 1-bit (CLK 2, CMD 3, D0 1); its power rail (expander
-// P14) is switched on in WioTrackerL2Board::begin(). Retried on every call
-// until it works, so a card inserted later is picked up the next time.
+// P14) is switched on in WioTrackerL2Board::begin(). Retried until it works --
+// at most every 5 s, a failed mount takes a while -- so a card inserted later
+// is picked up.
 static bool mountStorage() {
   static bool mounted = false;
+  static uint32_t last_try = 0;
   if (mounted) return true;
+  if (last_try && millis() - last_try < 5000) return false;
+  last_try = millis() | 1;
   SD_MMC.setPins(2, 3, 1);
   mounted = SD_MMC.begin("/sdcard", true /* 1-bit */);
   return mounted;
 }
 
-// ── WiFi (station, only while a map download runs) ───────────────────────────
-// Credentials in NVS, not in NodePrefs (whose on-flash layout stays fixed) and
-// not on the removable card.
-static bool loadWifi(char* ssid, size_t ssid_n, char* pass, size_t pass_n) {
+// ── Settings kept in NVS ─────────────────────────────────────────────────────
+// Not in NodePrefs (whose on-flash layout stays fixed) and not on the
+// removable card. One value per call: the namespace is opened and closed
+// around it; a namespace that won't open reads as the default.
+namespace nvs {
+struct Ns {
   Preferences p;
-  if (!p.begin("mc_wifi", true)) { ssid[0] = pass[0] = '\0'; return false; }
-  p.getString("ssid", ssid, ssid_n);
-  p.getString("pass", pass, pass_n);
-  p.end();
+  bool ok;
+  Ns(const char* ns, bool ro) { ok = p.begin(ns, ro); }
+  ~Ns() { if (ok) p.end(); }
+};
+static bool getBool(const char* ns, const char* key, bool def) { Ns n(ns, true); return n.ok ? n.p.getBool(key, def) : def; }
+static void putBool(const char* ns, const char* key, bool v) { Ns n(ns, false); if (n.ok) n.p.putBool(key, v); }
+static int  getI8(const char* ns, const char* key, int def) { Ns n(ns, true); return n.ok ? n.p.getChar(key, (int8_t)def) : def; }
+static void putI8(const char* ns, const char* key, int v) { Ns n(ns, false); if (n.ok) n.p.putChar(key, (int8_t)v); }
+static int  getU8(const char* ns, const char* key, int def) { Ns n(ns, true); return n.ok ? n.p.getUChar(key, (uint8_t)def) : def; }
+static void putU8(const char* ns, const char* key, int v) { Ns n(ns, false); if (n.ok) n.p.putUChar(key, (uint8_t)v); }
+static void getStr(const char* ns, const char* key, char* out, size_t n_out) {
+  out[0] = '\0';
+  Ns n(ns, true);
+  if (n.ok) n.p.getString(key, out, n_out);
+}
+static void putStr(const char* ns, const char* key, const char* v) { Ns n(ns, false); if (n.ok) n.p.putString(key, v); }
+}  // namespace nvs
+
+// ── WiFi (station, only while a map download runs) ───────────────────────────
+static bool loadWifi(char* ssid, size_t ssid_n, char* pass, size_t pass_n) {
+  nvs::getStr("mc_wifi", "ssid", ssid, ssid_n);
+  nvs::getStr("mc_wifi", "pass", pass, pass_n);
   return ssid[0] != '\0';
 }
 static void saveWifi(const char* ssid, const char* pass) {
-  Preferences p;
-  if (!p.begin("mc_wifi", false)) return;
-  p.putString("ssid", ssid);
-  p.putString("pass", pass);
-  p.end();
+  nvs::putStr("mc_wifi", "ssid", ssid);
+  nvs::putStr("mc_wifi", "pass", pass);
 }
 // Settings > WiFi's switch: off keeps the radio off for everything (scan, map
 // download). Kept with the credentials.
 static int8_t s_wifi_allowed = -1;   // read once (the status bar asks every second)
 static bool wifiAllowed() {
-  if (s_wifi_allowed < 0) {
-    Preferences p;
-    bool on = true;
-    if (p.begin("mc_wifi", true)) { on = p.getBool("on", true); p.end(); }
-    s_wifi_allowed = on;
-  }
+  if (s_wifi_allowed < 0) s_wifi_allowed = nvs::getBool("mc_wifi", "on", true);
   return s_wifi_allowed;
 }
-static void setWifiAllowed(bool on) {
-  s_wifi_allowed = on;
-  Preferences p;
-  if (!p.begin("mc_wifi", false)) return;
-  p.putBool("on", on);
-  p.end();
-}
+static void setWifiAllowed(bool on) { s_wifi_allowed = on; nvs::putBool("mc_wifi", "on", on); }
 // Map tools > Live tiles: missing tiles fetched over WiFi while the map is open.
-static bool liveTiles() {
-  Preferences p;
-  if (!p.begin("mc_wifi", true)) return true;
-  bool on = p.getBool("live", true);
-  p.end();
-  return on;
-}
-static void setLiveTiles(bool on) {
-  Preferences p;
-  if (!p.begin("mc_wifi", false)) return;
-  p.putBool("live", on);
-  p.end();
-}
+static bool liveTiles() { return nvs::getBool("mc_wifi", "live", true); }
+static void setLiveTiles(bool on) { nvs::putBool("mc_wifi", "live", on); }
 
 // Screen-lock PIN (Settings > Display & power > Screen PIN): digits, "" = none.
-// In NVS for the same reason as the WiFi credentials.
-static void loadPin(char* out, size_t n) {
-  Preferences p;
-  out[0] = '\0';
-  if (!p.begin("mc_lock", true)) return;
-  p.getString("pin", out, n);
-  p.end();
-}
-static void savePin(const char* pin) {
-  Preferences p;
-  if (!p.begin("mc_lock", false)) return;
-  p.putString("pin", pin);
-  p.end();
-}
+static void loadPin(char* out, size_t n) { nvs::getStr("mc_lock", "pin", out, n); }
+static void savePin(const char* pin) { nvs::putStr("mc_lock", "pin", pin); }
 
 // Accent colour (Settings > Display & power): an index into theme::ACCENTS.
-static int loadAccent() {
-  Preferences p;
-  if (!p.begin("mc_ui", true)) return 0;
-  int v = p.getUChar("accent", 0);
-  p.end();
-  return v;
-}
-static void saveAccent(int idx) {
-  Preferences p;
-  if (!p.begin("mc_ui", false)) return;
-  p.putUChar("accent", (uint8_t)idx);
-  p.end();
-}
+static int loadAccent() { return nvs::getU8("mc_ui", "accent", 0); }
+static void saveAccent(int idx) { nvs::putU8("mc_ui", "accent", idx); }
 // Settings > Storage > Kept per conversation (an index into histstore::KEEP).
-static int loadHistKeep() {
-  Preferences p;
-  if (!p.begin("mc_ui", true)) return -1;
-  int v = p.getChar("hkeep", -1);
-  p.end();
-  return v;
-}
-static void saveHistKeep(int idx) {
-  Preferences p;
-  if (!p.begin("mc_ui", false)) return;
-  p.putChar("hkeep", (int8_t)idx);
-  p.end();
-}
+static int loadHistKeep() { return nvs::getI8("mc_ui", "hkeep", -1); }
+static void saveHistKeep(int idx) { nvs::putI8("mc_ui", "hkeep", idx); }
 // Settings > Storage > Live map tiles: index into mapview::LIVE_CAP_MB, -1 = default.
-static int loadLiveCap() {
-  Preferences p;
-  if (!p.begin("mc_ui", true)) return -1;
-  int v = p.getChar("ltcap", -1);
-  p.end();
-  return v;
-}
-static void saveLiveCap(int idx) {
-  Preferences p;
-  if (!p.begin("mc_ui", false)) return;
-  p.putChar("ltcap", (int8_t)idx);
-  p.end();
-}
+static int loadLiveCap() { return nvs::getI8("mc_ui", "ltcap", -1); }
+static void saveLiveCap(int idx) { nvs::putI8("mc_ui", "ltcap", idx); }
 // Settings > Display & power > Tap to wake: a touch turns the dark screen on
-// (off: only the side button does).
-static bool loadTapWake() {
-  Preferences p;
-  if (!p.begin("mc_ui", true)) return true;
-  bool on = p.getBool("tapwake", true);
-  p.end();
-  return on;
-}
-static void saveTapWake(bool on) {
-  Preferences p;
-  if (!p.begin("mc_ui", false)) return;
-  p.putBool("tapwake", on);
-  p.end();
-}
+// (off: only the top button does).
+static bool loadTapWake() { return nvs::getBool("mc_ui", "tapwake", true); }
+static void saveTapWake(bool on) { nvs::putBool("mc_ui", "tapwake", on); }
 // Filesystem size and space in use (Settings > Storage), plus the card's own
 // size -- a card whose FAT partition is small (e.g. written by a Raspberry Pi
 // imager) shows both. The first free-space count on a big card takes a moment.
@@ -495,7 +453,7 @@ static void touchCb(lv_indev_t* indev, lv_indev_data_t* data) {
 static bool begin() {
   lv_display_t* disp = lv_display_create(SimLcdDisplay::W, SimLcdDisplay::H);
   lv_display_set_flush_cb(disp, flushCb);
-  static uint8_t buf[SimLcdDisplay::W * 40 * 2];   // same 40-line partial buffer as the board
+  static uint8_t buf[SimLcdDisplay::W * 40 * 2];   // 40 lines (the board: two half screens)
   lv_display_set_buffers(disp, buf, nullptr, sizeof(buf), LV_DISPLAY_RENDER_MODE_PARTIAL);
 
   lv_indev_t* indev = lv_indev_create();
@@ -506,6 +464,8 @@ static bool begin() {
 
 static bool touched() { return SimLcdDisplay::touchState().down; }
 static void swallowTouch() { s_swallow = true; }
+static void powerSave(bool, bool) {}   // the browser's page loop runs the sim
+static void idle(uint32_t) {}
 static void setBacklightPct(uint8_t pct) { (void)pct; }   // the browser canvas has no backlight
 
 // The host page preloads map tiles into the in-memory FS under /sdcard/maps.
diff --git a/examples/companion_radio/ui-lvgl/MapScreen.h b/examples/companion_radio/ui-lvgl/MapScreen.h
index 0a27f963..28d000fc 100644
--- a/examples/companion_radio/ui-lvgl/MapScreen.h
+++ b/examples/companion_radio/ui-lvgl/MapScreen.h
@@ -583,13 +583,7 @@ void UITask::mapDownloadPopup() {
   if (_dl_zmax < _map_z) _dl_zmax = _map_z + 3;
   if (_dl_zmax > src_max) _dl_zmax = src_max;   // the server has nothing finer
 
-  _dl_overlay = lv_obj_create(screen());
-  lv_obj_remove_style_all(_dl_overlay);
-  lv_obj_set_size(_dl_overlay, LV_PCT(100), LV_PCT(100));
-  lv_obj_set_style_bg_color(_dl_overlay, lv_color_hex(0x000000), 0);
-  lv_obj_set_style_bg_opa(_dl_overlay, LV_OPA_60, 0);
-  lv_obj_add_flag(_dl_overlay, LV_OBJ_FLAG_CLICKABLE);
-  lv_obj_remove_flag(_dl_overlay, LV_OBJ_FLAG_SCROLLABLE);
+  _dl_overlay = dimOverlay(screen());
 
   lv_obj_t* panel = lv_obj_create(_dl_overlay);
   anim::popup(_dl_overlay);
@@ -828,8 +822,9 @@ void UITask::mapDownloadTick() {
     bool got = false;
     while (dl.liveTake(z, x, y)) { mapview::s_cache.forgetMissing(z, x, y); got = true; }
     if (got && _screen == SCR_MAP) layoutMap();
-    // The WiFi goes 30 s after the map was left (a quick look elsewhere keeps it).
-    if (_screen != SCR_MAP) {
+    // The WiFi goes 30 s after the map was left or the screen went off (a
+    // quick look elsewhere keeps it).
+    if (_screen != SCR_MAP || _asleep) {
       if (!_map_left_ms) _map_left_ms = millis() | 1;
       else if (millis() - _map_left_ms > 30000) dl.liveEnd();
     }
diff --git a/examples/companion_radio/ui-lvgl/NavMap.h b/examples/companion_radio/ui-lvgl/NavMap.h
index badd7eb7..abdbab8a 100644
--- a/examples/companion_radio/ui-lvgl/NavMap.h
+++ b/examples/companion_radio/ui-lvgl/NavMap.h
@@ -476,13 +476,7 @@ void UITask::navToNode(const uint8_t* key, int32_t lat, int32_t lon, const char*
 
 lv_obj_t* UITask::navPopupPanel(const char* title, bool full) {
   navClosePopup();
-  _nav_overlay = lv_obj_create(screen());
-  lv_obj_remove_style_all(_nav_overlay);
-  lv_obj_set_size(_nav_overlay, LV_PCT(100), LV_PCT(100));
-  lv_obj_set_style_bg_color(_nav_overlay, lv_color_hex(0x000000), 0);
-  lv_obj_set_style_bg_opa(_nav_overlay, LV_OPA_60, 0);
-  lv_obj_add_flag(_nav_overlay, LV_OBJ_FLAG_CLICKABLE);
-  lv_obj_remove_flag(_nav_overlay, LV_OBJ_FLAG_SCROLLABLE);
+  _nav_overlay = dimOverlay(screen());
 
   lv_obj_t* panel = lv_obj_create(_nav_overlay);
   anim::popup(_nav_overlay);
@@ -529,13 +523,7 @@ static void navRowRight(lv_obj_t* row, const char* text, uint32_t col, int right
 
 void UITask::navTargetsPopup() {
   lv_obj_t* panel = navPopupPanel("Navigate to", true);
-  lv_obj_t* list = lv_obj_create(panel);
-  styleSurface(list, theme::BG);
-  lv_obj_set_width(list, LV_PCT(100));
-  lv_obj_set_flex_grow(list, 1);
-  lv_obj_set_flex_flow(list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(list, LV_SCROLLBAR_MODE_ACTIVE);
+  lv_obj_t* list = scrollList(panel);
 
   int32_t lat = 0, lon = 0;
   bool gps = _core->course.currentLocation(lat, lon);
@@ -914,13 +902,7 @@ static lv_obj_t* toolButton(lv_obj_t* row, const char* text, uint8_t act, bool a
 
 void UITask::navToolsPopup() {
   lv_obj_t* panel = navPopupPanel("Map tools", true);
-  lv_obj_t* list = lv_obj_create(panel);
-  styleSurface(list, theme::BG);
-  lv_obj_set_width(list, LV_PCT(100));
-  lv_obj_set_flex_grow(list, 1);
-  lv_obj_set_flex_flow(list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(list, LV_SCROLLBAR_MODE_ACTIVE);
+  lv_obj_t* list = scrollList(panel);
 
   sectionTitle(list, "TRAIL");
   _nav_trail_lbl = label(list, "", THEME_FONT_SMALL, theme::TEXT);
@@ -1035,20 +1017,31 @@ void UITask::navSetShareTarget(int sel) {
   the_mesh.savePrefs();
 }
 
+// A new file in /sdcard/trails named by the local time, "trail-YYYYMMDD-HHMM"
+// (seconds since boot before the clock is set), with `ext`; a second save in
+// the same minute gets "-2", "-3"...
+static void trailFilePath(char* path, size_t n, const char* ext, const NodePrefs* p) {
+  char stem[40];
+  uint32_t now = rtc_clock.getCurrentTime();
+  if (now > 1000000000UL) {
+    time_t t = (time_t)((int64_t)now + (int64_t)(p ? p->tz_offset_hours : 0) * 3600);
+    struct tm* ti = gmtime(&t);
+    snprintf(stem, sizeof(stem), "%s/trail-%04d%02d%02d-%02d%02d", navmap::TRAILS_DIR, ti->tm_year + 1900,
+             ti->tm_mon + 1, ti->tm_mday, ti->tm_hour, ti->tm_min);
+  } else {
+    snprintf(stem, sizeof(stem), "%s/trail-%lu", navmap::TRAILS_DIR, (unsigned long)(millis() / 1000));
+  }
+  snprintf(path, n, "%s%s", stem, ext);
+  struct stat st;
+  for (int k = 2; k < 100 && stat(path, &st) == 0; k++) snprintf(path, n, "%s-%d%s", stem, k, ext);
+  mapview::makeParents(path);
+}
+
 // GPX of the live trail (with the waypoints) to /sdcard/trails/.
 bool UITask::exportTrailGpx(char* name_out, size_t n) {
   if (!lvport::mountStorage()) return false;
   char path[64];
-  uint32_t now = rtc_clock.getCurrentTime();
-  if (now > 1000000000UL) {
-    time_t t = (time_t)((int64_t)now + (int64_t)_prefs->tz_offset_hours * 3600);
-    struct tm* ti = gmtime(&t);
-    snprintf(path, sizeof(path), "/sdcard/trails/trail-%04d%02d%02d-%02d%02d.gpx", ti->tm_year + 1900,
-             ti->tm_mon + 1, ti->tm_mday, ti->tm_hour, ti->tm_min);
-  } else {
-    snprintf(path, sizeof(path), "/sdcard/trails/trail-%lu.gpx", (unsigned long)(millis() / 1000));
-  }
-  mapview::makeParents(path);
+  trailFilePath(path, sizeof(path), ".gpx", _prefs);
   FILE* f = fopen(path, "w");
   if (!f) return false;
   navmap::FilePrint out(f);
@@ -1062,16 +1055,7 @@ bool UITask::exportTrailGpx(char* name_out, size_t n) {
 // The live trail to a new file in /sdcard/trails (named by the local time).
 bool UITask::saveTrailToCard(char* name_out, size_t n) {
   char path[64];
-  uint32_t now = rtc_clock.getCurrentTime();
-  if (now > 1000000000UL) {
-    time_t t = (time_t)((int64_t)now + (int64_t)_prefs->tz_offset_hours * 3600);
-    struct tm* ti = gmtime(&t);
-    snprintf(path, sizeof(path), "%s/trail-%04d%02d%02d-%02d%02d.trl", navmap::TRAILS_DIR, ti->tm_year + 1900,
-             ti->tm_mon + 1, ti->tm_mday, ti->tm_hour, ti->tm_min);
-  } else {
-    snprintf(path, sizeof(path), "%s/trail-%lu.trl", navmap::TRAILS_DIR, (unsigned long)(millis() / 1000));
-  }
-  mapview::makeParents(path);
+  trailFilePath(path, sizeof(path), ".trl", _prefs);
   FILE* f = fopen(path, "wb");
   if (!f) return false;
   navmap::FileRW io{ f };
@@ -1086,13 +1070,7 @@ bool UITask::saveTrailToCard(char* name_out, size_t n) {
 // device's own slot (manual saves without a card, the low-battery auto-save).
 void UITask::savedTrailsPopup() {
   lv_obj_t* panel = navPopupPanel("Saved trails", true);
-  lv_obj_t* list = lv_obj_create(panel);
-  styleSurface(list, theme::BG);
-  lv_obj_set_width(list, LV_PCT(100));
-  lv_obj_set_flex_grow(list, 1);
-  lv_obj_set_flex_flow(list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(list, LV_SCROLLBAR_MODE_ACTIVE);
+  lv_obj_t* list = scrollList(panel);
   navmap::scanTrails();
   for (int i = 0; i < navmap::s_st_n; i++) {
     char title[32], sub[48], path[64];
@@ -1328,13 +1306,7 @@ void UITask::navWaypointsPopup() {
   toolButton(r, UI_SYMBOL_PIN " Here (GPS)", navmap::TL_WP_HERE, true);
   toolButton(r, LV_SYMBOL_KEYBOARD " Coordinates", navmap::TL_WP_COORDS, false);
 
-  lv_obj_t* list = lv_obj_create(panel);
-  styleSurface(list, theme::BG);
-  lv_obj_set_width(list, LV_PCT(100));
-  lv_obj_set_flex_grow(list, 1);
-  lv_obj_set_flex_flow(list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(list, LV_SCROLLBAR_MODE_ACTIVE);
+  lv_obj_t* list = scrollList(panel);
   int32_t lat = 0, lon = 0;
   bool gps = _core->course.currentLocation(lat, lon);
   for (int i = 0; i < wp.count(); i++) {
diff --git a/examples/companion_radio/ui-lvgl/OtaScreen.h b/examples/companion_radio/ui-lvgl/OtaScreen.h
index 93ceebbd..ce5a5b74 100644
--- a/examples/companion_radio/ui-lvgl/OtaScreen.h
+++ b/examples/companion_radio/ui-lvgl/OtaScreen.h
@@ -174,6 +174,9 @@ void UITask::showOta() {
   buildOta();
 }
 
+// Something else holds the WiFi: a scan leaves it up.
+bool UITask::wifiInUse() const { return mapview::s_dl.active() || otaBusy() || ota::s_state == ota::CONNECTING; }
+
 bool UITask::otaBusy() const { return ota::s_state == ota::CHECKING || ota::s_state == ota::INSTALLING || ota::s_state == ota::DONE; }
 
 void UITask::buildOta() {
diff --git a/examples/companion_radio/ui-lvgl/RadioScreen.h b/examples/companion_radio/ui-lvgl/RadioScreen.h
index 9143f97b..efe0da68 100644
--- a/examples/companion_radio/ui-lvgl/RadioScreen.h
+++ b/examples/companion_radio/ui-lvgl/RadioScreen.h
@@ -24,21 +24,6 @@ static const int OPTS_LEN = 1024;
 static char* s_opts = psramBuf<char>(OPTS_LEN);   // dropdown options (LVGL copies them)
 
 // Label + optional hint on the left of a settings row; the control goes on the right.
-static lv_obj_t* settingRow(lv_obj_t* parent, const char* text, const char* hint) {
-  lv_obj_t* row = lv_obj_create(parent);
-  styleSurface(row, theme::SURFACE);
-  lv_obj_remove_flag(row, LV_OBJ_FLAG_SCROLLABLE);
-  lv_obj_set_size(row, LV_PCT(100), theme::ROW_H);
-  lv_obj_set_style_radius(row, theme::RADIUS, 0);
-  lv_obj_align(label(row, text, THEME_FONT_BODY, theme::TEXT), LV_ALIGN_TOP_LEFT, theme::PAD, hint ? 5 : 13);
-  if (hint) {
-    lv_obj_t* h = label(row, hint, THEME_FONT_SMALL, theme::TEXT_MUTED);
-    lv_label_set_long_mode(h, LV_LABEL_LONG_DOT);
-    lv_obj_set_size(h, 150, 15);
-    lv_obj_align(h, LV_ALIGN_BOTTOM_LEFT, theme::PAD, -5);
-  }
-  return row;
-}
 
 static lv_obj_t* rowDropdown(lv_obj_t* row, const char* opts, int sel, int width, lv_event_cb_t cb, uintptr_t which) {
   lv_obj_t* dd = lv_dropdown_create(row);
@@ -170,12 +155,7 @@ void UITask::radioFreqPopup(bool repeater) {
   using namespace radioview;
   if (s_overlay) return;
   s_freq_rpt = repeater;
-  s_overlay = lv_obj_create(screen());
-  lv_obj_remove_style_all(s_overlay);
-  lv_obj_set_size(s_overlay, LV_PCT(100), LV_PCT(100));
-  lv_obj_set_style_bg_color(s_overlay, lv_color_hex(0x000000), 0);
-  lv_obj_set_style_bg_opa(s_overlay, LV_OPA_60, 0);
-  lv_obj_add_flag(s_overlay, LV_OBJ_FLAG_CLICKABLE);
+  s_overlay = dimOverlay(screen());
   lv_obj_t* panel = lv_obj_create(s_overlay);
   anim::popup(s_overlay);
   lv_obj_set_size(panel, lv_display_get_horizontal_resolution(NULL) - 16, LV_SIZE_CONTENT);
diff --git a/examples/companion_radio/ui-lvgl/RepeaterScreen.h b/examples/companion_radio/ui-lvgl/RepeaterScreen.h
index 7d9b6ec6..8a13b3c9 100644
--- a/examples/companion_radio/ui-lvgl/RepeaterScreen.h
+++ b/examples/companion_radio/ui-lvgl/RepeaterScreen.h
@@ -48,7 +48,6 @@ void UITask::showRepeater() {
 
 void UITask::buildRepeater() {
   using namespace rptview;
-  using radioview::settingRow;
   using radioview::rowDropdown;
   lv_obj_t* body = newScreen("Repeater", true);
   NodePrefs* p = _prefs;
diff --git a/examples/companion_radio/ui-lvgl/SoundScreen.h b/examples/companion_radio/ui-lvgl/SoundScreen.h
index 08d4b8ba..18ff583f 100644
--- a/examples/companion_radio/ui-lvgl/SoundScreen.h
+++ b/examples/companion_radio/ui-lvgl/SoundScreen.h
@@ -268,7 +268,7 @@ void UITask::buildSoundRows(lv_obj_t* body, bool top) {
   using namespace sndview;
   if (top) {
     static const char* MODES[] = { "On", "Off", "Auto", "" };
-    lv_obj_t* row = radioview::settingRow(body, "Sound", "Auto: off with the app");
+    lv_obj_t* row = settingRow(body, "Sound", "Auto: off with the app");
     radioview::rowSegmented(row, MODES, soundctl::mode(_prefs), 150, onSoundMode, 0);
     return;
   }
diff --git a/examples/companion_radio/ui-lvgl/UITask.cpp b/examples/companion_radio/ui-lvgl/UITask.cpp
index fbc5da55..ba1135c5 100644
--- a/examples/companion_radio/ui-lvgl/UITask.cpp
+++ b/examples/companion_radio/ui-lvgl/UITask.cpp
@@ -13,10 +13,14 @@
 // this UI (all of it is this one file and the headers it includes) goes through
 // these, which swap each pair for the codepoint fonts/ui_emoji.c keeps the
 // flag's image under. Display only: what's stored and sent stays as it was.
+// A label given the text it already shows is left alone: the status bar, the
+// clocks and the live values are set every refresh, and each set is a redraw.
 extern "C" char* ui_emoji_flags(const char* s);
 static void ui_label_set_text(lv_obj_t* o, const char* t) {
   char* f = t ? ui_emoji_flags(t) : nullptr;   // t == NULL: LVGL's "redraw the current text"
-  lv_label_set_text(o, f ? f : t);
+  const char* s = f ? f : t;
+  const char* cur = lv_label_get_text(o);
+  if (!s || !cur || strcmp(cur, s) != 0) lv_label_set_text(o, s);
   lv_free(f);
 }
 static void ui_label_set_text_fmt(lv_obj_t* o, const char* fmt, ...) __attribute__((format(printf, 2, 3)));
@@ -121,6 +125,59 @@ static lv_obj_t* label(lv_obj_t* parent, const char* text, const lv_font_t* font
   return l;
 }
 
+// A list filling the rest of a flex column, scrolling on its own (the
+// scrollbar only while it moves).
+static lv_obj_t* scrollList(lv_obj_t* parent) {
+  lv_obj_t* l = lv_obj_create(parent);
+  styleSurface(l, theme::BG);
+  lv_obj_set_width(l, LV_PCT(100));
+  lv_obj_set_flex_grow(l, 1);
+  lv_obj_set_flex_flow(l, LV_FLEX_FLOW_COLUMN);
+  lv_obj_set_style_pad_row(l, theme::GAP, 0);
+  lv_obj_set_scrollbar_mode(l, LV_SCROLLBAR_MODE_ACTIVE);
+  return l;
+}
+
+// The dimmed full-screen layer under a popup; it swallows taps on what's below.
+static lv_obj_t* dimOverlay(lv_obj_t* parent) {
+  lv_obj_t* o = lv_obj_create(parent);
+  lv_obj_remove_style_all(o);
+  lv_obj_set_size(o, LV_PCT(100), LV_PCT(100));
+  lv_obj_set_style_bg_color(o, lv_color_hex(0x000000), 0);
+  lv_obj_set_style_bg_opa(o, LV_OPA_60, 0);
+  lv_obj_add_flag(o, LV_OBJ_FLAG_CLICKABLE);
+  lv_obj_remove_flag(o, LV_OBJ_FLAG_SCROLLABLE);
+  return o;
+}
+
+// A settings row: the label left (a muted hint under it, cut at `hint_w`),
+// room on the right for a switch / dropdown / slider.
+static lv_obj_t* settingRow(lv_obj_t* parent, const char* text, const char* hint, int hint_w = 150) {
+  lv_obj_t* row = lv_obj_create(parent);
+  styleSurface(row, theme::SURFACE);
+  lv_obj_remove_flag(row, LV_OBJ_FLAG_SCROLLABLE);
+  lv_obj_set_size(row, LV_PCT(100), theme::ROW_H);
+  lv_obj_set_style_radius(row, theme::RADIUS, 0);
+  lv_obj_align(label(row, text, THEME_FONT_BODY, theme::TEXT), LV_ALIGN_TOP_LEFT, theme::PAD, hint ? 5 : 13);
+  if (hint) {
+    lv_obj_t* h = label(row, hint, THEME_FONT_SMALL, theme::TEXT_MUTED);
+    lv_label_set_long_mode(h, LV_LABEL_LONG_DOT);
+    lv_obj_set_size(h, hint_w, 15);   // fixed height: cut, don't wrap onto the label
+    lv_obj_align(h, LV_ALIGN_BOTTOM_LEFT, theme::PAD, -5);
+  }
+  return row;
+}
+
+// A bare flex row / column sized to its content, taps passing through.
+static lv_obj_t* flexBox(lv_obj_t* parent, lv_flex_flow_t flow) {
+  lv_obj_t* b = lv_obj_create(parent);
+  lv_obj_remove_style_all(b);
+  lv_obj_remove_flag(b, LV_OBJ_FLAG_CLICKABLE);
+  lv_obj_set_size(b, LV_SIZE_CONTENT, LV_SIZE_CONTENT);
+  lv_obj_set_flex_flow(b, flow);
+  return b;
+}
+
 // A one-of-N choice: a row (or grid, with "\n" in the map) of checkable
 // buttons, `sel` checked (-1: none). `item` is the unchecked button colour —
 // SURFACE on a SURFACE_2 panel, SURFACE_2 on the page.
@@ -171,7 +228,6 @@ static void stylePrimary(lv_obj_t* b) {
     lv_obj_set_style_text_color(lv_obj_get_child(b, i), lv_color_hex(theme::BG), 0);
 }
 
-// Unread badge: amber pill with a count, on the right edge of `parent`.
 // "@[nick]" -> "@nick" in place, for one-line text (previews, quotes) where
 // the bubble's highlight doesn't reach.
 static void plainMentions(char* t) {
@@ -189,6 +245,7 @@ static void plainMentions(char* t) {
   *w = '\0';
 }
 
+// Unread badge: amber pill with a count, on the right edge of `parent`.
 static void badge(lv_obj_t* parent, int n, bool overflow) {
   if (n <= 0) return;
   lv_obj_t* b = lv_obj_create(parent);
@@ -357,7 +414,11 @@ void UITask::loop() {
   else if (btn_click) { if (!_asleep && !locked()) back(); }   // the side button doesn't wake: pockets
 
   if (_asleep) {
-    if (lvport::touched()) { lvport::swallowTouch(); if (_tap_wake) wake(); }   // off: the top (WAKE) button only
+    // Tap to wake (off: the top button only). An I2C read on the touch panel.
+    if (_tap_wake && (int32_t)(millis() - _next_touch_poll_ms) >= 0) {
+      _next_touch_poll_ms = millis() + 50;
+      if (lvport::touched()) { lvport::swallowTouch(); wake(); }
+    }
   } else {
     uint32_t aoff = autoOffMillis();
     if (aoff > 0 && lv_display_get_inactive_time(NULL) > aoff && !_core->clock.isRinging() && !otaBusy()) sleep();
@@ -438,6 +499,7 @@ void UITask::loop() {
     navPollTrackBack();
   }
 
+  uint32_t lv_next = 0;
   if (!_asleep) {
     if ((int32_t)(millis() - _next_status_ms) >= 0) {
       _next_status_ms = millis() + 1000;
@@ -479,8 +541,22 @@ void UITask::loop() {
       uint32_t sig = threadSignature();
       if (_thread_dirty || sig != _thread_sig) refreshThread();
     }
-    lv_timer_handler();
+    lv_next = lv_timer_handler();
   }
+  lvport::idle(idleMillis(lv_next));
+}
+
+// How long loop() may sleep: nothing is due before then. Not at all while the
+// mesh has packets queued; briefly while a melody plays (its notes are timed
+// here) or the app is connected (its frames are read one a pass).
+uint32_t UITask::idleMillis(uint32_t lv_next) {
+  if (the_mesh.hasPendingWork()) return 0;
+#ifdef PIN_BUZZER
+  if (_buzzer.isPlaying()) return 1;
+#endif
+  if (isClientConnected()) return 2;
+  if (_asleep) return 20;   // the buttons and tap to wake are polled every 50 ms
+  return lv_next < 10 ? lv_next : 10;   // LVGL's next timer: a refresh, an animation, input
 }
 
 void UITask::shutdown(bool restart) {
@@ -532,6 +608,7 @@ void UITask::sleep() {
   if (_asleep) return;
   _asleep = true;
   if (_display) _display->turnOff();
+  lvport::powerSave(true, _tap_wake);
   if ((_prefs && _prefs->auto_lock) || _pin[0]) lockScreen();   // Lock screen, or a screen PIN
 }
 
@@ -539,6 +616,7 @@ void UITask::wake() {
   lv_display_trigger_activity(NULL);
   if (!_asleep) return;
   _asleep = false;
+  lvport::powerSave(false, _tap_wake);
   if (_display) _display->turnOn();
   refreshStatusBar();
   if (_screen == SCR_HOME) refreshHome();
@@ -664,8 +742,9 @@ void UITask::refreshStatusBar() {
     lv_label_set_text(_status_time, "--:--");
   }
 
-  // Battery: the icon, then % or volts per Settings > Battery display.
-  uint16_t mv = getBattMilliVolts();
+  // Battery: the icon, then % or volts per Settings > Battery display. The
+  // smoothed reading (checkLowBattery): an ADC read blocks the loop for 10 ms.
+  uint16_t mv = _batt_mv ? _batt_mv : getBattMilliVolts();
   int pct = battery::percent(mv, _prefs ? _prefs->low_batt_mv : 0);
   const char* batt = pct > 80 ? LV_SYMBOL_BATTERY_FULL : pct > 55 ? LV_SYMBOL_BATTERY_3
                    : pct > 30 ? LV_SYMBOL_BATTERY_2 : pct > 10 ? LV_SYMBOL_BATTERY_1 : LV_SYMBOL_BATTERY_EMPTY;
@@ -769,6 +848,7 @@ lv_obj_t* UITask::newScreen(const char* title, bool with_back) {
   _nav_overlay = _nav_ta = _nav_kb = _nav_del_lbl = _nav_rec = _nav_avg_pill = nullptr;
   _nav_trail_lbl = _nav_trail_btn = _nav_reset_lbl = _nav_share_lbl = _nav_share_btn = _nav_tb_btn = nullptr;
   _wifi_ssid = _wifi_pass = _wifi_kb = _wifi_list = _wifi_status = nullptr;
+  if (_wifi_scanning && !wifiInUse()) lvport::netEnd();   // left mid-scan: the radio goes off
   _wifi_scanning = false;
   _ota_status = _ota_bar = _ota_btn = _ota_btn_lbl = nullptr;
   for (lv_obj_t*& t : _map_tiles) t = nullptr;
@@ -1071,7 +1151,7 @@ void UITask::setHomePage(int page) {
   else lv_obj_remove_flag(home::s_top, LV_OBJ_FLAG_HIDDEN);
   lv_obj_set_flex_flow(home::s_row, favs ? LV_FLEX_FLOW_ROW_WRAP : LV_FLEX_FLOW_ROW);
   if (favs) {
-    home::s_fav_sig = homeUnreadTotal();
+    home::s_fav_sig = unreadTotal();
     favGrid(home::s_row);   // DeviceScreen.h
   }
   int first = (page - home::MAIN) * home::PER_PAGE;
@@ -1092,7 +1172,7 @@ void UITask::setHomePage(int page) {
   refreshHome();
 }
 
-int UITask::homeUnreadTotal() {
+int UITask::unreadTotal() {
   return _core->dmUnreadTotal() + _core->history.getTotalChannelUnread() + _core->roomUnread();
 }
 
@@ -1109,12 +1189,12 @@ void UITask::refreshHome() {
     lv_label_set_text(_home_clock, "--:--");
     lv_label_set_text(_home_date, "time not synced");
   }
-  if (home::s_page == home::FAVS && home::s_row && homeUnreadTotal() != home::s_fav_sig) {
+  if (home::s_page == home::FAVS && home::s_row && unreadTotal() != home::s_fav_sig) {
     setHomePage(home::FAVS);   // new messages: the favourites' badges redrawn
     return;
   }
   if (!_home_unread) return;
-  int unread = homeUnreadTotal();
+  int unread = unreadTotal();
   if (unread > 0) lv_label_set_text_fmt(_home_unread, "%d", unread);
   else lv_label_set_text(_home_unread, "");
 }
@@ -1210,7 +1290,7 @@ static lv_obj_t* headerButton(lv_obj_t* hdr, const char* text, lv_event_cb_t cb,
 
 void UITask::buildChats() {
   lv_obj_t* body = newScreen("Messages", true);
-  if (_header && _core->dmUnreadTotal() + _core->history.getTotalChannelUnread() + _core->roomUnread() > 0)
+  if (_header && unreadTotal() > 0)
     headerButton(_header, LV_SYMBOL_OK " Read all", onMarkAllRead, 4, NULL);
 
   // Channels: favourites first (unless turned off), hold a row for its options
@@ -1299,6 +1379,7 @@ void UITask::buildChats() {
       if (_core->history.dmHistCountForContact(c.id.pub_key) > 0) {
         const DmHistEntry& e = _core->history.dmAtPos(_core->history.dmHistEntryForContact(c.id.pub_key, 0));
         snprintf(sub, sizeof(sub), "%s%s", e.outgoing ? "Me: " : "", e.text);
+        plainMentions(sub);
       } else {
         snprintf(sub, sizeof(sub), "%s", _core->rooms.isLoggedIn(c.id.pub_key) ? "Logged in" : "Tap to log in");
       }
@@ -1418,13 +1499,7 @@ void UITask::buildNearby() {
 
   _nearby_status = label(body, "", THEME_FONT_SMALL, theme::TEXT_MUTED);
 
-  _nearby_list = lv_obj_create(body);
-  styleSurface(_nearby_list, theme::BG);
-  lv_obj_set_width(_nearby_list, LV_PCT(100));
-  lv_obj_set_flex_grow(_nearby_list, 1);
-  lv_obj_set_flex_flow(_nearby_list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(_nearby_list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(_nearby_list, LV_SCROLLBAR_MODE_ACTIVE);
+  _nearby_list = scrollList(body);
 
   _nearby_sig = 0;
   refreshNearbyList();
@@ -1454,13 +1529,7 @@ void UITask::startNearbyScan() {
 // Dimmed full-screen overlay (swallows taps) holding a panel with the results.
 // A child of the current screen, so it goes away with it.
 void UITask::showScanPopup() {
-  _scan_overlay = lv_obj_create(screen());
-  lv_obj_remove_style_all(_scan_overlay);
-  lv_obj_set_size(_scan_overlay, LV_PCT(100), LV_PCT(100));
-  lv_obj_set_style_bg_color(_scan_overlay, lv_color_hex(0x000000), 0);
-  lv_obj_set_style_bg_opa(_scan_overlay, LV_OPA_60, 0);
-  lv_obj_add_flag(_scan_overlay, LV_OBJ_FLAG_CLICKABLE);
-  lv_obj_remove_flag(_scan_overlay, LV_OBJ_FLAG_SCROLLABLE);
+  _scan_overlay = dimOverlay(screen());
 
   lv_obj_t* panel = lv_obj_create(_scan_overlay);
   anim::popup(_scan_overlay);
@@ -1485,13 +1554,7 @@ void UITask::showScanPopup() {
   headerButton(hdr, LV_SYMBOL_REFRESH " Again", onNearbyScan, 44, NULL);
 
   _scan_status = label(panel, "", THEME_FONT_SMALL, theme::TEXT_MUTED);
-  _scan_list = lv_obj_create(panel);
-  styleSurface(_scan_list, theme::BG);
-  lv_obj_set_width(_scan_list, LV_PCT(100));
-  lv_obj_set_flex_grow(_scan_list, 1);
-  lv_obj_set_flex_flow(_scan_list, LV_FLEX_FLOW_COLUMN);
-  lv_obj_set_style_pad_row(_scan_list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(_scan_list, LV_SCROLLBAR_MODE_ACTIVE);
+  _scan_list = scrollList(panel);
 
   _scan_sig = 0;
   refreshScanPopup();
@@ -1805,7 +1868,6 @@ void UITask::nodeAction(uint8_t action) {
       char t[48];
       if (_core->waypoints.add(e.lat_e6, e.lon_e6, rtc_clock.getCurrentTime(), e.name[0] ? e.name : "Node")) {
         snprintf(t, sizeof(t), "Saved %s", _core->waypoints.at(_core->waypoints.count() - 1).label);
-        the_mesh.savePrefs();
         showToast(t);
       }
       break;
@@ -1931,14 +1993,8 @@ void UITask::buildThread() {
     headerButton(_header, LV_SYMBOL_SETTINGS, _thread_is_channel ? onChanThreadMenu : onConvThreadMenu, 4, NULL);
   }
 
-  _thread_list = lv_obj_create(body);
-  styleSurface(_thread_list, theme::BG);
-  lv_obj_set_width(_thread_list, LV_PCT(100));
-  lv_obj_set_flex_grow(_thread_list, 1);
-  lv_obj_set_flex_flow(_thread_list, LV_FLEX_FLOW_COLUMN);
+  _thread_list = scrollList(body);
   lv_obj_set_style_pad_all(_thread_list, theme::PAD, 0);
-  lv_obj_set_style_pad_row(_thread_list, theme::GAP, 0);
-  lv_obj_set_scrollbar_mode(_thread_list, LV_SCROLLBAR_MODE_ACTIVE);   // only while scrolling
 
   _compose_ta = nullptr;
   _keyboard = nullptr;
@@ -1990,7 +2046,7 @@ uint32_t UITask::threadSignature() const {
     sig = n;
     for (int j = 0; j < n && j < 8; j++) {
       const ChHistEntry& e = h.chAtPos(h.histEntryForChannel(_thread_channel, j));
-      sig = sig * 31 + e.timestamp + e.relay_status;
+      sig = sig * 31 + e.timestamp + e.relay_status + e.path_len;   // path_len: repeaters heard
     }
   } else {
     int n = h.dmHistCountForContact(_thread_key);
@@ -2140,13 +2196,7 @@ static void bubble(lv_obj_t* list, const char* from, const char* text, bool own,
   // the bubble two lines tall -- matters with the keyboard up.
   bool meta_in_header = from && from[0] && !status;
   if (from && from[0]) {
-    lv_obj_t* hdr = lv_obj_create(b);
-    styleSurface(hdr, theme::BG);
-    lv_obj_set_style_bg_opa(hdr, LV_OPA_TRANSP, 0);
-    lv_obj_remove_flag(hdr, LV_OBJ_FLAG_SCROLLABLE);
-    lv_obj_remove_flag(hdr, LV_OBJ_FLAG_CLICKABLE);
-    lv_obj_set_size(hdr, LV_SIZE_CONTENT, LV_SIZE_CONTENT);
-    lv_obj_set_flex_flow(hdr, LV_FLEX_FLOW_ROW);
+    lv_obj_t* hdr = flexBox(b, LV_FLEX_FLOW_ROW);
     lv_obj_set_style_pad_column(hdr, 8, 0);
     label(hdr, from, THEME_FONT_SMALL, theme::ACCENT);   // names are <= 31 chars: fits the bubble
     if (meta_in_header) label(hdr, meta, THEME_FONT_SMALL, theme::TEXT_MUTED);
@@ -2159,13 +2209,7 @@ static void bubble(lv_obj_t* list, const char* from, const char* text, bool own,
   }
 
   if (loc_idx >= 0) {   // position: navigate there / keep it as a waypoint
-    lv_obj_t* acts = lv_obj_create(b);
-    styleSurface(acts, theme::BG);
-    lv_obj_set_style_bg_opa(acts, LV_OPA_TRANSP, 0);
-    lv_obj_remove_flag(acts, LV_OBJ_FLAG_SCROLLABLE);
-    lv_obj_remove_flag(acts, LV_OBJ_FLAG_CLICKABLE);
-    lv_obj_set_size(acts, LV_SIZE_CONTENT, LV_SIZE_CONTENT);
-    lv_obj_set_flex_flow(acts, LV_FLEX_FLOW_ROW);
+    lv_obj_t* acts = flexBox(b, LV_FLEX_FLOW_ROW);
     lv_obj_set_style_pad_column(acts, 6, 0);
     lv_obj_set_style_pad_top(acts, 2, 0);
     msgLocButton(acts, UI_SYMBOL_COMPASS " Go", loc_idx, false, true);
@@ -2173,11 +2217,7 @@ static void bubble(lv_obj_t* list, const char* from, const char* text, bool own,
   }
 
   if (!meta_in_header) {   // the age, then the delivery mark in its colour (as L1)
-    lv_obj_t* line = lv_obj_create(b);
-    lv_obj_remove_style_all(line);
-    lv_obj_remove_flag(line, LV_OBJ_FLAG_CLICKABLE);
-    lv_obj_set_size(line, LV_SIZE_CONTENT, LV_SIZE_CONTENT);
-    lv_obj_set_flex_flow(line, LV_FLEX_FLOW_ROW);
+    lv_obj_t* line = flexBox(b, LV_FLEX_FLOW_ROW);
     lv_obj_set_flex_align(line, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
     lv_obj_set_style_pad_column(line, 6, 0);
     label(line, meta, THEME_FONT_SMALL, theme::TEXT_MUTED);
@@ -2399,13 +2439,7 @@ static void onKeyboardAlphabet(lv_event_t* e) {
 
 // One settings row: label left, dropdown right.
 static lv_obj_t* dropdownRow(lv_obj_t* parent, const char* text, const char* options, int sel) {
-  lv_obj_t* row = lv_obj_create(parent);
-  styleSurface(row, theme::SURFACE);
-  lv_obj_remove_flag(row, LV_OBJ_FLAG_SCROLLABLE);
-  lv_obj_set_size(row, LV_PCT(100), theme::ROW_H);
-  lv_obj_set_style_radius(row, theme::RADIUS, 0);
-  lv_obj_t* l = label(row, text, THEME_FONT_BODY, theme::TEXT);
-  lv_obj_align(l, LV_ALIGN_LEFT_MID, theme::PAD, 0);
+  lv_obj_t* row = settingRow(parent, text, NULL);
   lv_obj_t* dd = lv_dropdown_create(row);
   lv_dropdown_set_options_static(dd, options);
   lv_dropdown_set_selected(dd, sel);
@@ -2428,19 +2462,7 @@ static void onGpsSwitch(lv_event_t* e) {
 
 // pref == nullptr: the caller wires the switch itself.
 static lv_obj_t* switchRow(lv_obj_t* parent, const char* text, const char* sub, uint8_t* pref) {
-  lv_obj_t* row = lv_obj_create(parent);
-  styleSurface(row, theme::SURFACE);
-  lv_obj_remove_flag(row, LV_OBJ_FLAG_SCROLLABLE);
-  lv_obj_set_size(row, LV_PCT(100), theme::ROW_H);
-  lv_obj_set_style_radius(row, theme::RADIUS, 0);
-  lv_obj_t* l = label(row, text, THEME_FONT_BODY, theme::TEXT);
-  lv_obj_align(l, LV_ALIGN_TOP_LEFT, theme::PAD, sub ? 5 : 13);
-  if (sub) {
-    lv_obj_t* h = label(row, sub, THEME_FONT_SMALL, theme::TEXT_MUTED);
-    lv_label_set_long_mode(h, LV_LABEL_LONG_DOT);
-    lv_obj_set_size(h, 236, 15);   // clear of the switch
-    lv_obj_align(h, LV_ALIGN_BOTTOM_LEFT, theme::PAD, -5);
-  }
+  lv_obj_t* row = settingRow(parent, text, sub, 236);   // the hint clear of the switch
   lv_obj_t* sw = lv_switch_create(row);
   lv_obj_set_size(sw, 46, 24);
   lv_obj_align(sw, LV_ALIGN_RIGHT_MID, -theme::PAD, 0);
@@ -2574,7 +2596,7 @@ void UITask::schemaRows(lv_obj_t* body, uint8_t page) {
     }
     uint8_t v = settings::get(*_prefs, st);
     if (st.offset == offsetof(NodePrefs, buzzer_volume)) {   // a five-step slider, heard on release
-      lv_obj_t* row = radioview::settingRow(body, st.label, NULL);
+      lv_obj_t* row = settingRow(body, st.label, NULL);
       lv_obj_t* sl = lv_slider_create(row);
       lv_slider_set_range(sl, 0, 4);
       lv_slider_set_value(sl, v, LV_ANIM_OFF);
@@ -2585,12 +2607,7 @@ void UITask::schemaRows(lv_obj_t* body, uint8_t page) {
       continue;
     }
     if (st.offset == offsetof(NodePrefs, display_brightness)) {   // a slider here instead of five steps
-      lv_obj_t* row = lv_obj_create(body);
-      styleSurface(row, theme::SURFACE);
-      lv_obj_remove_flag(row, LV_OBJ_FLAG_SCROLLABLE);
-      lv_obj_set_size(row, LV_PCT(100), theme::ROW_H);
-      lv_obj_set_style_radius(row, theme::RADIUS, 0);
-      lv_obj_align(label(row, st.label, THEME_FONT_BODY, theme::TEXT), LV_ALIGN_LEFT_MID, theme::PAD, 0);
+      lv_obj_t* row = settingRow(body, st.label, NULL);
       lv_obj_t* sl = lv_slider_create(row);
       lv_slider_set_range(sl, 5, 100);
       uint8_t pct = _prefs->display_brightness_pct ? _prefs->display_brightness_pct
@@ -2617,19 +2634,7 @@ void UITask::schemaRows(lv_obj_t* body, uint8_t page) {
       o += strlen(opts + o);
     }
     opts[o] = '\0';
-    lv_obj_t* row = lv_obj_create(body);
-    styleSurface(row, theme::SURFACE);
-    lv_obj_remove_flag(row, LV_OBJ_FLAG_SCROLLABLE);
-    lv_obj_set_size(row, LV_PCT(100), theme::ROW_H);
-    lv_obj_set_style_radius(row, theme::RADIUS, 0);
-    lv_obj_t* l = label(row, st.label, THEME_FONT_BODY, theme::TEXT);
-    lv_obj_align(l, LV_ALIGN_TOP_LEFT, theme::PAD, st.hint ? 5 : 13);
-    if (st.hint) {
-      lv_obj_t* h = label(row, st.hint, THEME_FONT_SMALL, theme::TEXT_MUTED);
-      lv_label_set_long_mode(h, LV_LABEL_LONG_DOT);
-      lv_obj_set_size(h, 176, 15);   // fixed height: cut, don't wrap onto the label
-      lv_obj_align(h, LV_ALIGN_BOTTOM_LEFT, theme::PAD, -5);
-    }
+    lv_obj_t* row = settingRow(body, st.label, st.hint, 176);
     lv_obj_t* dd = lv_dropdown_create(row);
     lv_dropdown_set_options(dd, opts);
     lv_dropdown_set_selected(dd, v);
diff --git a/examples/companion_radio/ui-lvgl/UITask.h b/examples/companion_radio/ui-lvgl/UITask.h
index 3b3b4744..c65eef0d 100644
--- a/examples/companion_radio/ui-lvgl/UITask.h
+++ b/examples/companion_radio/ui-lvgl/UITask.h
@@ -235,7 +235,6 @@ public:
   void pinRowRefresh();
   void accentRow(lv_obj_t* body);   // Settings > Display & power > Accent colour
   void setAccent(int idx);
-  void showFavourites();
   void showDiag();
   void diagTab(int tab);
   void diagResetPopup();
@@ -252,7 +251,7 @@ public:
 
   // Kept for main.cpp's sim hooks (ui-new API).
   void openContactDM(const ContactInfo& ci) { openDM(ci.id.pub_key); }
-  void openAdminFor(const ContactInfo& ci, bool from_picker) { (void)ci; (void)from_picker; }
+  void openAdminFor(const ContactInfo& ci, bool from_picker) { (void)from_picker; openAdmin(ci.id.pub_key); }
 
 private:
   enum Screen : uint8_t { SCR_HOME, SCR_CHATS, SCR_CONTACTS, SCR_THREAD, SCR_SETTINGS, SCR_NEARBY, SCR_NODE, SCR_MAP, SCR_WIFI, SCR_SETTINGS_NAV, SCR_CLOCK, SCR_RADIO, SCR_CHANNEL_EDIT, SCR_ADMIN, SCR_BOT, SCR_DIAG, SCR_COMPASS, SCR_SCOPES, SCR_REPEATER, SCR_MELODY, SCR_QUICK, SCR_ADMIN_PICK, SCR_OTA, SCR_STORAGE, SCR_GPS };
@@ -278,6 +277,7 @@ private:
   void otaTick();
   void otaLeave();
   bool otaBusy() const;
+  bool wifiInUse() const;   // a map download or an update holds the WiFi
   void buildNearby();
   void refreshNearbyList();
   uint32_t nearbySignature() const;
@@ -344,7 +344,7 @@ private:
   void lockPoll();
   void favGrid(lv_obj_t* grid);
   void favRefresh();
-  int homeUnreadTotal();
+  int unreadTotal();   // DMs, channels and rooms
   void buildDiag();
   void refreshDiag();
   void buildCompass();
@@ -363,8 +363,10 @@ private:
   void sleep();
   void toggleMute();
   uint32_t _next_wake_poll_ms = 0;
+  uint32_t _next_touch_poll_ms = 0;   // tap to wake, while the screen is off
   bool _wake_down = false;
   uint32_t autoOffMillis() const;
+  uint32_t idleMillis(uint32_t lv_next);
   void checkLowBattery();
 
 #ifdef PIN_BUZZER
@@ -402,7 +404,7 @@ private:
   uint32_t _map_left_ms = 0;          // when the map was left, for dropping live tiles' WiFi
   bool     _admin_from_pick = false;   // Admin opened from its Home tile (back returns there)
   uint32_t _prune_armed_ms = 0;
-  uint16_t _batt_mv = 0;         // smoothed, for the low-battery shutdown
+  uint16_t _batt_mv = 0;         // smoothed, read every 8 s: the status bar and the low-battery shutdown
   uint32_t _next_batt_ms = 0;
   lv_obj_t* _prune_lbl = nullptr;
   // Screen PIN (DeviceScreen.h); stored in NVS (lvport::loadPin)
diff --git a/examples/companion_radio/ui-lvgl/WifiScreen.h b/examples/companion_radio/ui-lvgl/WifiScreen.h
index e38f7a9c..8a27ea36 100644
--- a/examples/companion_radio/ui-lvgl/WifiScreen.h
+++ b/examples/companion_radio/ui-lvgl/WifiScreen.h
@@ -175,7 +175,7 @@ void UITask::pollWifiScan() {
   }
   if (n > 0) lv_obj_remove_flag(_wifi_list, LV_OBJ_FLAG_HIDDEN);
   lv_label_set_text(_wifi_status, n > 0 ? "Tap a network, then enter its password." : "No networks found.");
-  if (!mapview::s_dl.active()) lvport::netEnd();   // the scan switched the radio on
+  if (!wifiInUse()) lvport::netEnd();   // the scan switched the radio on
 }
 
 void UITask::wifiPick(int idx) {
diff --git a/variants/wio-tracker-l2/WioTrackerL2Board.cpp b/variants/wio-tracker-l2/WioTrackerL2Board.cpp
index 0560fa3f..5dd668f2 100644
--- a/variants/wio-tracker-l2/WioTrackerL2Board.cpp
+++ b/variants/wio-tracker-l2/WioTrackerL2Board.cpp
@@ -14,6 +14,11 @@ static const uint8_t ADS_REG_CONFIG     = 0x01;
 static const uint16_t ADS_CFG_BATT = 0x8000 | 0x4000 | 0x0200 | 0x0100 | 0x0080 | 0x0003;
 // +/-4.096V FSR -> 125uV/LSB; battery is behind a x2 divider -> 0.25 mV/LSB
 static const float ADS_MV_PER_LSB = 0.125f * 2.0f;
+static const uint32_t BATT_SETTLE_MS = 1;       // divider on -> input settled (measured: at once)
+static const uint32_t BATT_REUSE_MS  = 2000;    // the UI, diagnostics and the app all ask
+
+// GT911: its command register; 0x05 = sleep
+static const uint8_t GT911_ADDR = 0x5D;
 
 bool WioTrackerL2Board::expWriteReg(uint8_t reg, uint8_t val) {
   Wire.beginTransmission(TCA9535_ADDR);
@@ -64,7 +69,7 @@ bool WioTrackerL2Board::initExpander() {
   delay(10);
   expSetOutput(EXP_PIN_TF_EN, HIGH);
   delay(10);
-  expSetOutput(EXP_PIN_BAT_ADC_EN, HIGH);
+  expSetOutput(EXP_PIN_BAT_ADC_EN, LOW);   // the divider only draws while a reading is taken
   delay(10);
   expSetOutput(EXP_PIN_GNSS_EN, HIGH);
   delay(10);
@@ -216,15 +221,40 @@ int16_t WioTrackerL2Board::adsReadRaw() {
 // A failed or zero ADS1115 read (the I2C bus busy or the ADC not answering)
 // keeps the last good value instead of reporting 0 mV -- that read as 0 % in
 // the status bar and could trip the low-battery shutdown. Retried once first.
+// The divider is powered only around the reading; one taken in the last 2 s
+// is reused.
 uint16_t WioTrackerL2Board::getBattMilliVolts() {
   if (!expander_ok) return 0;  // BAT_ADC_EN rail never came up
+  if (batt_mv_last && millis() - batt_read_ms < BATT_REUSE_MS) return batt_mv_last;
 
+  expWritePin(EXP_PIN_BAT_ADC_EN, HIGH);
+  delay(BATT_SETTLE_MS);
   for (int attempt = 0; attempt < 2; attempt++) {
     int16_t raw = adsReadRaw();
     if (raw > 0) {
       batt_mv_last = (uint16_t)(raw * ADS_MV_PER_LSB);
-      return batt_mv_last;
+      break;
     }
   }
+  expWritePin(EXP_PIN_BAT_ADC_EN, LOW);
+  batt_read_ms = millis();
   return batt_mv_last;
 }
+
+void WioTrackerL2Board::touchSleep() {
+  if (!expander_ok) return;
+  expWritePin(EXP_PIN_TP_INT, LOW);   // held low while it sleeps (it is, from the reset sequence on)
+  Wire.beginTransmission(GT911_ADDR);
+  Wire.write((uint8_t)0x80);
+  Wire.write((uint8_t)0x40);
+  Wire.write((uint8_t)0x05);
+  Wire.endTransmission();
+}
+
+void WioTrackerL2Board::touchWake() {
+  if (!expander_ok) return;
+  expWritePin(EXP_PIN_TP_INT, HIGH);   // 2-5 ms high wakes it
+  delay(5);
+  expWritePin(EXP_PIN_TP_INT, LOW);
+}
+
diff --git a/variants/wio-tracker-l2/WioTrackerL2Board.h b/variants/wio-tracker-l2/WioTrackerL2Board.h
index 60ef6e6e..6cbf3485 100644
--- a/variants/wio-tracker-l2/WioTrackerL2Board.h
+++ b/variants/wio-tracker-l2/WioTrackerL2Board.h
@@ -20,7 +20,7 @@
 #define ADS1115_ADDR   0x48
 
 // TCA9535 pin numbering: 0..7 = port 0 (P00..P07), 8..15 = port 1 (P10..P17)
-#define EXP_PIN_WAKE_BTN     0   // input  - side WAKE button
+#define EXP_PIN_WAKE_BTN     0   // input  - WAKE button (top edge)
 #define EXP_PIN_I2C_IRQ      1   // input  - shared I2C IRQ
 #define EXP_PIN_SD_DETECT    2   // input  - microSD card detect
 #define EXP_PIN_TP_INT       3   // output - touch panel interrupt (driven for reset seq)
@@ -57,8 +57,6 @@ public:
   // antenna away from class-D switching noise and to save battery
   void setSpeakerAmp(bool on) { expWritePin(EXP_PIN_PA_EN, on); }
 
-  // hardware reset pulse to the L76K GNSS (active HIGH on this board); the
-  // module keeps almanac/ephemeris across it, so this is a warm restart
   // GNSS rail: off saves the whole receiver when GPS is disabled; on re-runs
   // the power-up reset so the module comes back cleanly
   void setGnssPower(bool on) {
@@ -73,6 +71,10 @@ public:
   // Grove expansion port rail (nothing on-board depends on it)
   void setGrovePower(bool on) { expWritePin(EXP_PIN_GROVE_EN, on); }
 
+  bool gnssPowered() const { return (out_shadow[EXP_PIN_GNSS_EN >> 3] >> (EXP_PIN_GNSS_EN & 7)) & 1; }
+
+  // hardware reset pulse to the L76K GNSS (active HIGH on this board); the
+  // module keeps almanac/ephemeris across it, so this is a warm restart
   void gnssReset() {
     expWritePin(EXP_PIN_GNSS_RST, HIGH);
     delay(10);
@@ -82,6 +84,11 @@ public:
   // WAKE button on expander P00: pressed = level differs from boot baseline
   bool readWakeButton();
 
+  // GT911 touch controller: sleep (a few mA -> tens of uA) while the screen is
+  // off and a touch shouldn't wake it; wake with a pulse on its INT line.
+  void touchSleep();
+  void touchWake();
+
   // VBUS presence via the AW35615 USB-C controller (I2C 0x22)
   bool isExternalPowered() override;
   int awRead(uint8_t reg);   // AW35615 register, -1 on error
@@ -95,6 +102,7 @@ private:
   bool aw_ok = false;              // AW35615 USB-C controller responded at probe
   uint8_t wake_btn_baseline = 0;   // idle level of P00, captured at init
   uint16_t batt_mv_last = 0;       // last good battery reading (a failed read keeps it)
+  uint32_t batt_read_ms = 0;       // when it was taken (reads closer together reuse it)
 
   int expReadInputs();   // 16-bit input register pair, -1 on error
 
diff --git a/variants/wio-tracker-l2/WioTrackerL2Display.h b/variants/wio-tracker-l2/WioTrackerL2Display.h
index 65fcc2b7..5277245c 100644
--- a/variants/wio-tracker-l2/WioTrackerL2Display.h
+++ b/variants/wio-tracker-l2/WioTrackerL2Display.h
@@ -33,6 +33,7 @@ class WioTrackerL2Backlight : public lgfx::v1::ILight {
   static constexpr uint8_t REG_LED0_PWM = 0x18;
 
   uint8_t _brightness = 153;  // 60%
+  bool _standby = false;      // chip disabled (the screen is off)
 
   void writeReg(uint8_t reg, uint8_t value) {
     Wire.beginTransmission(LP5814_I2C_ADDR);
@@ -41,13 +42,7 @@ class WioTrackerL2Backlight : public lgfx::v1::ILight {
     Wire.endTransmission();
   }
 
-public:
-  bool init(uint8_t brightness) override {
-    Wire.beginTransmission(LP5814_I2C_ADDR);
-    if (Wire.endTransmission() != 0) {
-      return false;  // LP5814 not found
-    }
-
+  void configure() {
     writeReg(REG_DEVICE_CONFIG0, 0x01);  // chip enable
     writeReg(REG_MAX_CURRENT, 0x01);     // 51 mA max current
     writeReg(REG_ENABLE_CONTROL, 0x00);  // outputs off while configuring
@@ -59,12 +54,28 @@ public:
     writeReg(REG_ENABLE_CONTROL, 0x0F);  // enable all 4 channels
     writeReg(REG_UPDATE, 0x55);          // latch (LP5814 requires 0x55)
     delay(5);
+  }
 
+public:
+  bool init(uint8_t brightness) override {
+    Wire.beginTransmission(LP5814_I2C_ADDR);
+    if (Wire.endTransmission() != 0) {
+      return false;  // LP5814 not found
+    }
+    configure();
     setBrightness(brightness);
     return true;
   }
 
+  // 0 (LovyanGFX's sleep()) puts the chip in standby; the next level brings it
+  // back, set up again.
   void setBrightness(uint8_t brightness) override {
+    if (brightness == 0) {
+      writeReg(REG_DEVICE_CONFIG0, 0x00);   // chip disable: standby
+      _standby = true;
+      return;
+    }
+    if (_standby) { configure(); _standby = false; }
     for (uint8_t i = 0; i < 4; i++) {
       writeReg(REG_LED0_PWM + i, brightness);
     }
diff --git a/variants/wio-tracker-l2/target.cpp b/variants/wio-tracker-l2/target.cpp
index dd548cb3..e5ee78bb 100644
--- a/variants/wio-tracker-l2/target.cpp
+++ b/variants/wio-tracker-l2/target.cpp
@@ -10,7 +10,7 @@ WRAPPER_CLASS radio_driver(radio, board);
 
 ESP32RTCClock fallback_clock;
 AutoDiscoverRTCClock rtc_clock(fallback_clock);
-MicroNMEALocationProvider gps(Serial1, &rtc_clock);
+L2GpsProvider gps(Serial1, &rtc_clock);
 EnvironmentSensorManager sensors(gps);
 
 #ifdef DISPLAY_CLASS
@@ -22,6 +22,28 @@ EnvironmentSensorManager sensors(gps);
 void buzzerAmpPower(bool on) { board.setSpeakerAmp(on); }
 #endif
 
+void L2GpsProvider::begin() {
+  board.setGnssPower(true);   // with the power-up reset
+  if (_uart_off) {            // back from stop(): the UART again
+    Serial1.setRxBufferSize(1024);
+    Serial1.begin(GPS_BAUD_RATE, SERIAL_8N1, PIN_GPS_TX, PIN_GPS_RX);
+    _uart_off = false;
+  }
+  MicroNMEALocationProvider::begin();
+}
+
+void L2GpsProvider::stop() {
+  MicroNMEALocationProvider::stop();
+  // The UART's TX idling high would feed the unpowered module through its pin.
+  Serial1.end();
+  pinMode(PIN_GPS_RX, INPUT);   // PIN_GPS_RX: the module's RX, our TX
+  _uart_off = true;
+  board.setGnssPower(false);
+}
+
+void L2GpsProvider::reset() { board.gnssReset(); }
+bool L2GpsProvider::isEnabled() { return board.gnssPowered(); }
+
 bool radio_init() {
   MESH_DEBUG_PRINTLN("radio_init: rtc + sx1262 init");
   fallback_clock.begin();
diff --git a/variants/wio-tracker-l2/target.h b/variants/wio-tracker-l2/target.h
index 145c464e..f493b866 100644
--- a/variants/wio-tracker-l2/target.h
+++ b/variants/wio-tracker-l2/target.h
@@ -14,11 +14,24 @@
   #include <helpers/ui/MomentaryButton.h>
 #endif
 
+// The L76K's power and reset lines are on the IO expander, out of the NMEA
+// provider's reach: begin() / stop() / reset() drive them here, so GPS off
+// (Settings, duty cycling) really powers the receiver down.
+class L2GpsProvider : public MicroNMEALocationProvider {
+  bool _uart_off = false;
+public:
+  using MicroNMEALocationProvider::MicroNMEALocationProvider;
+  void begin() override;
+  void stop() override;
+  void reset() override;
+  bool isEnabled() override;
+};
+
 extern WioTrackerL2Board board;
 extern WRAPPER_CLASS radio_driver;
 extern AutoDiscoverRTCClock rtc_clock;
 extern EnvironmentSensorManager sensors;
-extern MicroNMEALocationProvider gps;
+extern L2GpsProvider gps;
 
 #ifdef DISPLAY_CLASS
   extern DISPLAY_CLASS display;