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+# Wio Tracker L1 — Extended Companion Radio Firmware
+
+This branch extends the official MeshCore companion radio firmware for the **Seeed Wio Tracker L1** (NRF52840 + SX1262 + SH1106 OLED 128×64 + GPS + buzzer + 5-way joystick).
+
+## New Build Variants
+
+In addition to the standard `_companion_radio_usb` and `_companion_radio_ble` builds, two new variants are available with a full **settings screen**:
+
+| Environment | Interface |
+|---|---|
+| `WioTrackerL1_companion_radio_usb_settings` | USB serial |
+| `WioTrackerL1_companion_radio_ble_settings` | Bluetooth LE |
+
+The settings screen is accessed by navigating to the last page of the home screen and pressing Enter.
+
+## New Features
+
+### Settings Screen
+
+All settings are saved to flash and restored on next boot.
+
+| Setting | Options | Default |
+|---|---|---|
+| Display brightness | 5 levels (very dim → max) | Medium |
+| Buzzer | ON / OFF | ON |
+| TX Power | 2 – 22 dBm | Board default |
+| Auto-off delay | 5 s / 15 s / 30 s / 60 s / never | 15 s |
+| GPS update interval | off / 30 s / 1 min / 5 min / 15 min / 30 min | off |
+| Timezone | UTC−12 .. UTC+14 | UTC |
+| Low battery shutdown | off / 3.0 V – 3.5 V | 3.4 V |
+| Battery display | icon / % / voltage | icon |
+
+### Clock Screen
+
+A dedicated clock page on the home screen shows the current time and date, synchronized from GPS. Timezone is applied from the settings above.
+
+### Battery Display Modes
+
+The top-right battery indicator can be switched between:
+- **Icon** — classic fill bar
+- **%** — percentage, where 0% = low battery shutdown threshold (if set), otherwise 3.2 V
+- **V** — live voltage (e.g. `3.84V`)
+
+Battery voltage is filtered with an exponential moving average (α = 0.2) to smooth out ADC noise from uneven load.
+
+### Low Battery Auto-Shutdown
+
+When the filtered battery voltage drops below the configured threshold, the device displays a warning on screen for 2 seconds and then shuts down gracefully. The threshold is configurable from the settings screen (3.0 V – 3.5 V) or can be disabled.
+
+## Bug Fixes
+
+- **Buzzer mute at startup** — the saved mute preference is now respected during the startup sound; previously the buzzer was always unmuted on boot regardless of the saved setting.
+- **Brightness change delay** — brightness changes are now applied instantly without triggering a flash write on every keypress; flash is written only when exiting the settings screen.
+
+## Build & Release
+
+Firmware is built automatically via GitHub Actions on every `wio-tracker-*` tag push.
+Pre-built `.uf2` files are published in the [Releases](../../releases) section.
+
+To flash: copy the `.uf2` file to the device while it is in bootloader mode (double-press reset).
+
+## Syncing with Upstream
+
+This branch tracks [meshcore-dev/MeshCore](https://github.com/meshcore-dev/MeshCore).
+To pull upstream updates:
+
+```bash
+git fetch upstream
+git rebase upstream/main
+git push origin wio-tracker-l1-improvements --force-with-lease
+```