Joystick-only UX constraints: 4 directions + Enter + Back. No text entry except inside KeyboardWidget. Everything else navigable with cursor + press.
Status legend: 📋 planned · 🚧 in progress · ✅ done · ❌ rejected/deferred
---
## Priority queue
### ✅ Mark-all-read at type level
Hold Enter on the MESSAGE mode-select screen (DM / Channels / Rooms) opens a 1-item context menu "Mark all read". Acts on the currently highlighted mode and shows a brief confirmation alert.
Implementation:
- New `UITask::clearAllDMUnread()` — `memset` over `_dm_unread_table`
A 2×3 grid (six slots) of pinned contacts on its own home page, between Clock and Messages. Joystick picks a tile, Enter opens the existing DM conversation or sends a pre-set quick reply.
Data model:
- New field in NodePrefs: `uint8_t favourite_contacts[6][6]` — first 6 bytes of each contact's `pub_key` (enough to disambiguate locally)
- Lookup at render time: walk contacts, match prefix, render name + unread badge
- Empty slot renders as "+" placeholder; Enter on empty opens a contact picker (existing UI)
Pinning UX:
- In QuickMsg DM list, long-press on a contact → context menu → "Pin to dial" → asks which of the 6 slots
- Unpin via the same menu (only shown when contact is already pinned)
Schema bump: add `favourite_contacts` to NodePrefs, bump `SCHEMA_SENTINEL` low byte.
Render layout (250×122 landscape e-ink):
```
╔══════════════════════════════╗
║ Favourites ║
╠══════════════════════════════╣
║ ┌──────┐ ┌──────┐ ┌──────┐ ║
║ │Alice │ │Bob 3 │ │ + │ ║
║ └──────┘ └──────┘ └──────┘ ║
║ ┌──────┐ ┌──────┐ ┌──────┐ ║
║ │Carol │ │ + │ │ + │ ║
║ └──────┘ └──────┘ └──────┘ ║
╚══════════════════════════════╝
```
Joystick navigation is natural with 6 tiles (UP/DOWN between rows, LEFT/RIGHT within row).
Rationale: auto-off only blanks the display, the firmware keeps running, so the RAM trail survives every idle scenario. Typical use is a single trip start→stop while wearing the device; persisting across reboots is rarely wanted. RAM-only avoids ~1400 flash writes/day and the LittleFS wear that comes with continuous logging.
- Live ring: `BreadcrumbEntry[BC_RAM_CAP]` in `UITask` (or a dedicated component). Each entry `int32_t lat_1e6, int32_t lon_1e6, uint32_t ts` = 12 B. Cap = 256 → 3 KB RAM. nRF52840 (256 KB RAM) has plenty of headroom.
- Wrap-on-write: oldest entry replaced when buffer full.
- Reboot wipes the live trail (intentional; matches the "this trip" model).
**Snapshot slots on flash** (user-initiated only):
-`/breadcrumb.0`, `/breadcrumb.1`, `/breadcrumb.2` — three named slots
- Each file: small header (count, start_ts, end_ts, total_distance_m) + entry array
- Written only on explicit "Save trail" action — zero background writes, zero wear concern
- Optional: auto-save to slot 0 on detected low-battery shutdown (single write before going dark)
UI screens (LEFT/RIGHT cycles):
1.**Summary** — total distance (km), elapsed time (h:mm), point count, current speed (from last 2 samples), GPS fix indicator
2.**Trail map** — ASCII bounding-box plot. Auto-fit the polygon, current position marked `X`, start marked `*`. UP/DOWN zoom, LEFT/RIGHT pan when zoomed.
3.**Last N entries list** — scroll through recent points with timestamp + delta from previous.
Joystick actions:
- Enter → toggle live logging on/off (status bar shows `*` when active, like auto-advert `A`)
Schema impact: new prefs fields `uint8_t breadcrumb_interval_idx`, `uint8_t breadcrumb_min_delta_idx`. Sentinel bump. The slot files are separate from prefs.
Edge cases:
- No GPS fix: skip sampling, status indicator dims
- Low-batt shutdown: optional auto-save to slot 0 (one write) before powerdown
- Memory: 3 KB RAM is negligible on this MCU; if RAM ever tightens, drop to 128 entries
---
## Backlog (not yet prioritised)
### Compass to contact
Select contact in Nearby → Enter → fullscreen compass. Arrow points to last-known position of contact relative to my GPS heading (need accel/mag or compute heading from movement). Distance below. Updates every 1 s.
Joystick: Enter from Nearby toggles, Back exits. Heading-from-GPS requires moving; for stationary use, would need magnetometer that the L1 board does or doesn't have — check.
### SOS broadcast
Configurable in Settings › System › SOS:
- Target: channel index or DM contact
- Message template (uses placeholders)
Trigger: Hold Back + Hold Enter for 3 s on any screen → confirmation popup ("Send SOS?") → Enter to send. Sends with `{loc}` and `{batt}` filled. 30 s cooldown.
### Range test
Tools › Range Test:
- Pick a node from contacts/nearby
- Enter starts pinging every 5 s, logs RTT + RSSI + SNR (ring ~30)
- Display shows current values + 30-sample sparkline (block characters)
- Enter stops; Hold Enter for context menu (reset, change target)
### Quiet hours
Settings › Sound › Quiet Hours:
- Enable on/off
- Start HH (LEFT/RIGHT to change, 24 h)
- End HH
When within window: buzzer set to "off" (overrides setting), display brightness → 0. Restores prefs values when window ends. Time source: rtc_clock.
### Channel scanner home page
Toggleable in Settings › Home Pages. Lists channels with: name, unread count, last message age. Enter opens the channel. Sort by recency by default; LEFT/RIGHT toggles to alphabetical.
### Contact distance sort
QuickMsg DM list: a 4-th sort mode (currently sorted by message count). LEFT/RIGHT on the list header cycles: name | message-count | recency | distance. Distance uses GPS pos from contact's last advert.
### Signal stats screen
Tools › Stats:
- Battery voltage 60-min sparkline
- RSSI of last 30 received packets
- Noise floor current
- Free heap (if available)
Read-only. UP/DOWN switches between metrics. Bottom shows current value as text.
### Auto-reply trigger words with sensor placeholders
Bot already has a single trigger word. Extend to a small table of (trigger, reply-with-placeholder) pairs:
- "temp?" → replies with `{temp}`
- "loc?" → replies with `{loc}`
- "batt?" → replies with `{batt}`
Stored in NodePrefs as fixed-size table (say 4 pairs × 16 B). UI: edit pairs in Tools › Auto-Reply Bot.
### Lock-screen unread count
Show `12 new` or two-line `5 DM / 7 ch` on lock screen below the time. Reuses existing `_hist`/`_dm_hist` unread counters. Cosmetic only, no schema change.
### Power profile presets
Settings › Profile: Indoor / Outdoor / Expedition. Each pre-fills:
- Auto-off seconds
- GPS interval
- Auto-advert interval
- Brightness
Single Enter applies. Stored as `uint8_t profile_idx` with hardcoded value tables.
### Battery curve calibration
Settings › System › Batt Calibration: edit 5 voltage breakpoints used to convert mV → %. UP/DOWN selects breakpoint, LEFT/RIGHT changes voltage in 50 mV steps. Helps users with non-standard LiPos report accurate %.
### Mark-read at type level — already covered above as priority
### Display test pattern
Tools › Display Test: full-screen grid + bars + Lemon glyph dump. Useful for verifying driver/font changes after flashing.
### Group "who's online" ping
From channel view, Hold Enter → "Who's online?". Sends 0-hop discovery to channel members, collects responses for 10 s, shows a list with RSSI. Similar to existing Nearby active discovery but scoped to a channel.
---
## Deferred
### ❌ Morse keyboard
Cute but niche. Skip unless explicitly requested.
### ❌ Buzzer EVENTS_STOPPED IRQ chaining
Marginal real-world gain (2 ms between notes during melody playback only), high risk on the PWM peripheral.
### ❌ Vibration feedback
Wio Tracker L1 doesn't have a haptic motor. N/A.
---
## Implementation order suggestion
1.**Mark-all-read** — smallest patch, biggest day-to-day comfort gain
2.**Favourites dial** — new home page + new prefs field; touches familiar areas (QuickMsg context menu, NodePrefs, schema sentinel bump)
3.**GPS breadcrumb** — largest of the three; introduces a new flash file and a Tools sub-screen with multiple views
After #3, re-prioritise the backlog with the user.
Defensive `if (ch_idx >= MAX_GROUP_CHANNELS) return;` at function entry — prevents ring-buffer pollution in case any future caller forgets the upstream guard. With C1 fixed this should never trigger, but the cost is zero.
## High
### 📋 `findChannelIdx` scans all-zero secret in uninitialised slots
for (int i = 0; i <MAX_GROUP_CHANNELS;i++){//fullrange,notnum_channels
if (memcmp(ch.secret, channels[i].channel.secret, 32) == 0) return i;
}
```
If `ch.secret` is all-zero (uninitialised or corrupted) and an unused slot is also all-zero, the function returns that unused slot as a "match". Upstream code — needs upstream fix or local override.
### 📋 `saveChannels` writes all 40 slots to `/channels2`
`saveChannels` calls `getChannelForSave(idx, ch)` in a loop; `BaseChatMesh::getChannel(idx)` returns `true` for any `idx < MAX_GROUP_CHANNELS` (including uninitialised slots). Result: file is always ~2.7 KB (40 × 68 B). The `loadChannels` sanity check (skip empty secret) papers over the symptom but the root cause is in save.
### 📋 `msgRead(0)` wipes the whole DM unread table
When the companion app reads the last message from the offline queue, all on-device badges disappear. Previously discussed and a fix was reverted as "intended sync behaviour" — keep as known limitation; document or restrict to "Favourites Dial badges only".
### ✅ `loadPrefsInt` scopes `trail_units_idx` reset to the 0xC0DE0003 jump
The reset is now gated on `sentinel == 0xC0DE0003` so newer mismatches (e.g. 0xC0DE0004 → 0xC0DE0005, which both saved the field correctly) no longer clobber the user's choice.
`strlen((char *) &cmd_frame[1])` will read past frame end if the app sends no `\0` in the first 31 bytes. Bounded by frame buffer size (172+) so practically safe but fragile.
The first `handleInput()` after `begin()` uses `_cap = _visible` (caller hint), not the real screen capacity. Render always precedes input in practice, but the invariant is fragile.
### 📋 `renderDiscoverDetail` potential negative length in `strncpy`
`char title[24]` for `"RE:" + nick[32]` truncates long nicks silently.
## Priority for merge
Fix status after this pass:
- ✅ C1 + C2 — `findChannelIdx == -1` guarded at both channel-recv paths; `addChannelMsg` defends against bogus index
- ✅ H4 — `trail_units_idx` reset scoped to the 0xC0DE0003 jump
- 📋 H1 + H2 — still open; need coordinated fix in upstream `BaseChatMesh` (`findChannelIdx` should iterate `num_channels`, not `MAX_GROUP_CHANNELS`; `saveChannels` should stop at the first uninitialised slot) or a local override
- 📋 H3 — left as known limitation pending UX call
Medium/Low items can ride along with other refactors in the affected files.