MeshCore-Solo/docs/development/l2-roadmap.md

Wio Tracker L2 (ui-lvgl) roadmap

The L1 → L2 feature port and its audit are done (2026-09-26). This is the plan for what comes next, in order. Tick items off as they land.

Decisions already made:

• Buttons: WAKE (side, expander P00) turns the screen off / on. USER/BOOT goes back; holding it mutes / unmutes the device.
• Placeholders: the "+" popup next to a text field is the placeholder UI; it must offer every placeholder and appear at every field that sends text.
• Message history: kept on the SD card, about 100 per conversation to start with.
• OTA: firmware comes from this fork's GitHub Releases.
• PIN: screen lock only, for now.

1. Quick fixes

• Keyboard: a key that closes it (so far a message could only be sent).
• "+" placeholders at every field that sends text (compose, quick messages, bot replies).
• Short, terse descriptions on buttons and rows.
• WiFi off switch.
• Buttons as decided above.

2. Arduino-ESP32 3.x, PSRAM

• A separate L2 env on pioarduino 55.03.312-1 (Arduino-ESP32 3.3.12, IDF 5.5): Wio_Tracker_L2_companion_solo_lvgl_v3; the 2.0.17 env stays until the new one passes the hardware checklist.
• Port: speaker (new I2S driver), BLE (NimBLE), ESP-NOW (IDF 5 callbacks); HTTPS map download and LovyanGFX build unchanged (check on the device).
• Large buffers in PSRAM (psramBuf): trail drawing, tile cache, map marks, list rows, keyboard maps, message metadata. Internal heap free at runtime: 2.0.17 147.8 KB; 3.x 128.2 KB before, 147.9 KB after (static RAM 109 → 71 KB). Measured with -D UI_HEAP_REPORT. History and a larger trail come to PSRAM with stage 3.
• Full hardware checklist, then make the new env the default.

3. Data on the SD card

Postponed (2026-09-26): the user may extend this stage first.

• Message history on SD, kept across reboots (~100 per conversation; the newest ones cached in PSRAM).
• Trail sized to the device: thousands of points in PSRAM (now 512), saved to SD.

4. UI layout

L1 splits its tools into many small screens because of the joystick and the 128x64 display; the L2 groups them where they are used instead.

• Tools: trail, live share and arrival alert stay in the map (its tools popup, with their options behind "Options"); the advert (send now, auto-advert) is in Nearby; Repeater, Admin (a list of repeaters and room servers) and Diagnostics are Home tiles next to Favourites, Compass, Clock and Bot. The melody editor stays in Sound.
• Settings in L1's order: display, sound, radio (with Bluetooth, WiFi), system, keyboard, contacts & messages.
• Every status icon L1 has (Bluetooth, GPS, alarm, mute, auto-advert, trail, live share, repeater) plus arrival alert; background modes in the accent colour instead of L1's blinking.

5. Security and internet

• Screen-lock PIN: 4-8 digits in NVS (lvport::loadPin), asked on every wake and after a reboot, 5 misses pause entry for 30 s; Settings > Display & power > SECURITY.
• Map tiles fetched live while online: the map queues tiles it is missing, TileDownloader fetches them one at a time over WiFi (connected on the first miss, dropped 30 s after leaving the map) and saves them to the card; Map > ☰ > Live tiles (NVS, on by default).
• One-button OTA from GitHub Releases: Settings > System > Firmware update (OtaScreen.h). The latest release's -Wio-Tracker-L2-ota.bin (app image; build-solo-firmwares.yml now publishes *_solo_lvgl) is streamed over TLS verified with the framework's CA bundle into the idle slot of default_16MB.csv (two 6.25 MB app slots, no layout change), chip id checked, then restart. Arduino 3.x builds only.
• Before the first release with L2: make the 3.x env the *_solo_lvgl one (stage 2's last item), then test an update end to end.

6. Theme

• A consistent style, written down in Theme.h: accent fill = the primary action (Download, Install, Save, Go), dim accent fill = selected / on (tabs, chips, segments -- also the default theme's CHECKED), accent text = names, counts, modes; one card radius for buttons and rows, pills for chips, RADIUS_SM inside; slightly lighter surfaces. Accent colour selectable (Settings > Display & power > LOOK: amber, orange, coral, violet, cyan, lime; NVS mc_ui).
• Light motion (Anim.h): a new screen emerges from the middle (a background-coloured cover fades while the content drifts 6 px), Home pages slide after a swipe, popups and toasts rise and fade in, buttons shrink a little while pressed.
• Frame time measured on the device (-D UI_PERF_TEST: walks screens by itself, prints render + flush per refresh): ~48 → ~33 ms per transition frame with uncompressed fonts and two 120-line buffers. Internal-RAM / DMA buffers, -O2, hot code in IRAM, two draw threads, system malloc: no gain. The rest is LVGL's software rendering at 320x240.
• Status bar icons in equal cells; muted is a speaker with a cross.
• Under an own message: the age and a small mark as in L1 (✓ n repeaters for channel posts; ✓ / ✗ / ... for DMs) instead of the words.
• The path window of a message: quote, time and hops, a path diagram (sender → repeaters → this device), repeaters that relayed an own post, an own DM's delivery in words.
• Tile download popup fits the screen; its WiFi button went (WiFi is set up in one place, Settings).
• Splash screen (Splash.h): MeshCore wordmark, SOLO, the Solo and the upstream version, build date, loading dots.

7. Research: LVGL for the other displays

• Find out whether LVGL on every display variant gives consistency and a nicer look more easily. Adopt only if the result is better and every feature is kept (L1: 128×64 OLED, nRF52, RAM already 68% used).

Backlog (found along the way)

• USB power detection: WioTrackerL2Board::isExternalPowered() reads STATUS0 (0x40) bit 7 of the chip at I2C 0x22 and always gets 0 with USB plugged in (0x40 reads 0x01). Needed for a charging indicator and for skipping the low-battery shutdown on the cable. Find the right chip / register (devices on the bus: 0x14, 0x18, 0x21, 0x22, 0x2c, 0x34, 0x48, 0x5d). Found 2026-09-26.

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.
• Live tiles: don't keep them, or give them a bounded cache on the card so they never fill it.
• Vector maps and other tile sources (to think through).