System Architecture

System Architecture

XNODE is the embedded edge node inside the MKME X stack. It does not replace XTOC or XCOM. It gives those tools a wrist or handheld endpoint for fast operator actions and map awareness.

Logical layers

Layer	Products	Responsibility
Command and shared picture	XTOC	TOC workflows, roster, packets, map overlays, SATCOM/ATAK/ADS-B, shared workspace, bridges, and exports.
Field operator software	XCOM	Offline PWA tools, radio planning, tactical map, field packet workflows, mesh/MANET/APRS/Reticulum/ViperGram transport, XTOC import.
Wearable/handheld endpoint	XNODE	Watch/T-Deck UI, GPS, mesh, SOS, CheckIn, message alerts, local map, synced overlays, BLE bridge.
Passive intel watch	XINTEL	Local audio transcription, intel rules, ViperGram decode, XTOC event ingest.
Local analysis	XCORE	Offline AI summaries, anomaly scans, SITREPs, aircraft pattern checks, packet drafting, XTOC/XCOM context.

Data flow

The common flow is:

Field observation
  -> XNODE SOS / CheckIn / mesh / GPS
  -> XCOM or XTOC import / bridge
  -> XTOC packet archive and map overlay
  -> XCOM and XNODE synced tactical picture
  -> XINTEL and XCORE add monitoring and analysis when present

The reverse flow is:

TOC action in XTOC
  -> roster, basemap, overlay, alert, or message update
  -> XCOM and/or BLE bridge
  -> XNODE watch/T-Deck display
  -> operator sees marker, alert, message, map, or task context

XNODE BLE bridge

The firmware exposes bridge capabilities for the host tools. The current README lists:

• sync
• location
• meshtastic
• basemap
• mapOverlay
• newsNotifications
• ble

These are the host-facing surfaces that let XTOC and XCOM treat the watch as an operational peripheral instead of a standalone toy app.

Storage model

XNODE stores compact state on device:

• Installed basemap raster in SPIFFS.
• Basemap center/zoom/projection settings.
• Persisted overlay markers in /spiffs/osmmap/overlays.jsonl.
• Pushed alerts/news items.
• Meshtastic user/channel configuration.
• Device settings for GPS, WiFi, BLE, display, power, and UI.

The watch is not meant to be the authoritative operations database. XTOC/XCOM own richer operational records; XNODE keeps the field-critical subset.

Runtime model

XNODE is built on the existing watch UI stack with LVGL, PlatformIO, Arduino ESP32, board-specific HALs, and shared app modules. Platform-specific behavior is selected by PlatformIO environments and compile flags:

• LILYGO_WATCH_ULTRA
• LILYGO_WATCH_S3
• LILYGO_T_DECK_PLUS

The firmware keeps shared app logic where possible and isolates hardware differences in HAL and build configuration.

Current implementation anchors

• PlatformIO environments: platformio.ini
• T-Deck HAL: src/hardware/tdeck_plus_hal.*
• T-Watch Ultra HAL: src/hardware/twatch_ultra_hal.*
• GPS controller: src/hardware/gpsctl.*
• BLE XNODE bridge: src/hardware/ble/xnode.*
• Meshtastic service: src/app/meshtastic/meshtastic_service.cpp
• Tactical map app: src/app/osmmap/osmmap_app_main.cpp
• Regression checks: support/regression_checks.py