MeshCore J2ME Client

MeshCore Java ME (MIDP 2.0 / CLDC 1.1) mobile client for MeshCore Companion Radio over Wi-Fi TCP.

This README is user-UI focused: it explains every major screen, what options/buttons you get there, what happens after each action, and the normal flows users follow.

Get started

• Demo video: YouTube - MeshCore J2ME: Bringing Mesh network to Old QWERTY Phones

• Download latest release: MeshCore J2ME v1.0.0

• Build from source: Go to Build and run

UI preview

`MainMenuScreen`

`MapViewCanvas` trace (4)

`MapViewCanvas` trace (3)

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Tested Devices & Platforms

• Nokia Asha 210 — primary tested hardware device.
• KEmulator (kemnnx64) — tested on Windows, Linux, and macOS via the KEmulator emulator. This lets you run the app on a desktop computer without a physical device.
• J2ME-Loader — also works on Android using J2ME-Loader, a J2ME emulator app (install the JAR/JAD and grant network access as needed).

Any device or emulator supporting MIDP 2.0 / CLDC 1.1 with TCP networking should work.

Nokia Asha 210 — primary tested device

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1) What the app is for

MeshCore lets you:

• Connect your phone to a MeshCore node by IP/port over Wi-Fi TCP.
• Chat in public channels in real time.
• Send and receive direct messages (DM) to and from contacts.
• Work with repeaters — view discovered repeaters, authenticate when required, request telemetry, and run trace paths through them.
• Manage contacts — add manually or via QR code, view details, copy public keys and coordinates, share your identity with others.
• Manage channels — create private channels with auto-generated secrets, join private or hashtag channels, share channel info via QR.
• Build and edit multi-hop routing paths for direct messages, either by picking repeaters from a list or entering raw path bytes manually.
• Use map-based navigation — view node, contact, and repeater positions on a tiled map, measure distances, and build trace routes visually.
• Run diagnostics:
  • Zero-hop ping — verify direct reachability to a node
  • Manual trace path — build a hop path and trace it step by step
  • Map-based trace path — select hops visually on the map and run the trace
  • Noise floor — live monitoring of the radio noise level
  • Telemetry — request and decode telemetry frames from nodes/repeaters
  • Activity log — inspect protocol and runtime events in real time
• Manage node and app settings — update node parameters, clear message history, and monitor storage usage.

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2) UI experience overview

Typical user session:

1. Open app → ConnectScreen
2. Enter node IP/host and TCP port → Connect
3. Land on MainMenuScreen
4. Navigate via dashboard tiles and the bottom bar:
   • Contacts
   • Channels
   • Repeaters
   • Notifications
   • Favorites
5. Open More → Tools for trace/map/noise floor/activity diagnostics
6. Use Back from any screen to return to the previous context

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3) Screen-by-screen guide (buttons, options, behavior)

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3.1 Connect and entry screens

ConnectScreen

Purpose Start a session with your MeshCore node.

What you enter

• Host/IP address of the node
• TCP port number

Buttons/commands

• Connect

What happens

• App opens a TCP connection and starts the protocol handshake and sync sequence.
• On success: opens MainMenuScreen.
• On failure: stays on the connect flow and shows an error notification. You can retry immediately.

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3.2 Main navigation screens

MainMenuScreen (Canvas dashboard)

Purpose Central navigation hub once connected.

UI areas

• Left dashboard card: node info, current noise floor reading, latest status context (last message, last activity).
• Right tiles: Notifications badge + Favorites shortcut.
• Bottom bar: Contacts / Channels / Repeaters.

Buttons/commands

• Select — opens currently highlighted destination
• Advert • Zero Hop — sends advert mode change to zero-hop (direct neighbors only)
• Advert • Flood — sends advert mode change to flood/routed (propagates through network)
• Disconnect / Connect To — closes or starts a node session depending on current state
• More — opens the secondary menu (MoreMenuCanvas)

What each action does

• Advert • Zero Hop and Advert • Flood control how your node advertises itself to the mesh. Zero-hop keeps advertisements local; flood propagates them further.
• Disconnect closes the active TCP session cleanly. The button changes to Connect To when disconnected.
• More opens the extended menu for adding contacts/channels, sharing, maps, tools, settings, and more.

MoreMenuCanvas

Purpose Access additional non-primary features.

Buttons/commands

• Select
• Back

Menu options

• Add Contact
• Add Channel
• Share My Contact
• Map
• Tools
• Settings
• About
• Exit

What happens

• Add Contact → AddContactOptionsScreen: choose to add manually or scan a QR code.
• Add Channel → AddChannelOptionsScreen: create or join channels in multiple ways.
• Share My Contact → ShareQrScreen: generates your own contact payload as a QR for others to scan.
• Map → MapViewCanvas: full map view of all known nodes and repeaters.
• Tools → ToolsScreen: diagnostics and trace tools.
• Settings → SettingsScreen: node and app configuration.
• About → AboutScreen: app/project version info.
• Exit → terminates the MIDlet cleanly.
• Back → returns to main menu.

ToolsScreen

Purpose Entry point for diagnostics and path analysis tools.

List options

• Trace Path • Manual — manually build a hop path and run a trace
• Trace Path • Using Map — visually select hops on the map and run a trace
• Noise Floor — live RF noise floor monitoring
• Activity Log — view protocol and runtime event history

Buttons/commands

• Back

What happens

• Selecting any row opens the matching tool screen.
• Back returns to the previous menu.

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3.3 Messaging screens

ChannelListScreen

Purpose View, open, and manage all channels you have joined.

Buttons/commands

• Channel Info — view name, type, and secret for the selected channel
• Share with QR Code — generate a shareable QR for the selected channel
• Remove Channel — remove selected channel (asks for confirmation first)
• Back — return to previous screen

Selection behavior Pressing select on a channel row opens ChannelScreen for that channel.

ChannelInfoScreen

Purpose Show selected channel metadata, including secret key info for private channels.

What it displays

• Public channel: simple public-channel label, no secret.
• Private/hashtag channels:
  • Channel name
  • Type (Public / Hashtag / Private)
  • Secret key in hex format

Buttons/commands

• Copy (only shown for non-public channels)
• Back

What happens

• Copy opens a text box with the secret key pre-filled for easy manual copy and sharing.
• Back returns to ChannelListScreen.

PrivateChannelSecretScreen

Purpose Final step after creating a new private channel — shows the auto-generated secret.

Buttons/commands

• Back

What happens

• Displays the channel name and generated secret key with an instruction to share it with other participants.
• Back returns to the add-channel flow.

ChannelScreen (chat canvas)

Purpose Public channel real-time chat view and message composer.

Buttons/commands

• Write — opens text entry box for composing a message
• Back — leave channel view
• Clear History — removes all locally stored messages for this channel
• In text input box: Send / Back

What each action does

• Write enters the compose state. Type your message and press Send to transmit it to the channel.
• Clear History removes the local message log but does not affect what other users see.
• Back exits the channel view and returns to ChannelListScreen.

ContactsScreen

Purpose Contact list for initiating direct messages and contact-level actions.

Buttons/commands

• Search — filter the contact list by typing a name or key fragment
• Write Message — open a DM with the selected contact
• Refresh — request the latest contact list and status from the node
• Back — return to previous screen

What each action does

• Search filters the visible list in real time as you type.
• Write Message opens DMScreen for the selected contact.
• Refresh re-syncs the contact list from the connected node.

DMScreen (direct message chat)

Purpose 1-to-1 conversation with the selected contact, with per-contact path/route control.

Buttons/commands

• Write — compose a direct message
• Back — leave DM view
• Clear History — remove local DM history for this contact
• Set Path — open the path editor to configure the route to this contact
• Reset Path — clear the stored route and return to default flood/direct behavior
• In text input: Send / Back

What each action does

• Write + Send transmits a direct message to the selected contact using the configured path.
• Set Path opens PathListScreen where you can add/remove repeater hops or enter raw path bytes.
• Reset Path clears the saved path immediately (after confirmation) so future messages use default routing.
• Clear History removes only the local message log.

PathListScreen (per-contact route editor)

Purpose Edit and save the routing path for one contact — i.e., which repeater hops messages to that contact should use.

Buttons/commands

• Add hop — open repeater picker and append a hop
• Remove hop — remove the selected hop from the path
• Enter Path Manually — open a guided hex editor for raw path bytes
• Save — write the configured path to the contact route
• Reset Path — confirm and clear the stored route entirely
• Back — if the path was modified, prompts to save before leaving

What happens

• The header shows the current path as Path: ... followed by the repeater rows.
• Building a path: press Add hop to open RepeaterPickerScreen, pick a repeater, and repeat for additional hops.
• Manual editing lets you enter raw path bytes directly if you know the hex values.
• Save stores the path so all subsequent DMs to this contact use it.

ContactActionsScreen

Purpose Action center for a selected contact or repeater — all per-contact operations in one place.

Typical actions available (varies by contact/repeater type)

• Open DM
• View contact details
• Request telemetry
• Run trace or ping
• Add/remove from Favorites
• Remove contact
• View on map

Buttons/commands

• Back

ContactDetailsScreen

Purpose Read-only view of a contact's identity and location metadata.

Buttons/commands

• Copy Key — copies the full public key text to clipboard/text box
• Copy Coordinates — copies advertised GPS coordinates if available
• Back

FavoritesScreen

Purpose Quick access list of contacts you have marked as favorites.

Buttons/commands

• Write Message — open DM with selected favorite
• Remove from Favorites — unstar the selected contact
• Back

NotificationsScreen

Purpose Funnel for new incoming events — new messages, pings, alerts.

Buttons/commands

• Open — jump directly to the relevant conversation or screen for this notification
• Back

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3.4 Contact and channel sharing/adding screens

AddContactOptionsScreen

Purpose Choose how to add a contact or repeater identity to your local list.

List options

• Add Manually (Name + Pub Key) — type the contact name and full public key
• Scan QR Code — use the camera to scan a MeshCore contact QR

What happens

• Manual → ManualAddContactScreen: enter name + public key, press OK to add.
• QR → AddFromQrScanScreen: camera preview opens, decodes the QR. Valid MeshCore contact QR adds the contact and shows a success alert. Invalid QR shows an error alert and returns.

AddChannelOptionsScreen

Purpose Add channels using multiple supported methods.

List options

• Create Private Channel — generate a new private channel with an auto-created secret key
• Join Private Channel — enter a channel name + existing 32-character hex secret key
• Join Hashtag Channel — enter a hashtag name (the # prefix is added automatically if omitted)
• Scan QR code — scan an existing channel share QR

What happens

• Create private → CreatePrivateChannelScreen → then PrivateChannelSecretScreen with the generated secret.
• Join private: enter name + secret; on valid input the channel is added immediately.
• Join hashtag: enter the hashtag name; channel is added.
• Scan QR → AddChannelFromQrScanScreen: valid QR adds the channel; invalid QR shows an error.

ShareQrScreen and ShareContactScreen

Purpose Share your identity or a channel's details outward as a scannable QR code or copyable text payload.

Used by

• ChannelListScreen → Share with QR Code for the selected channel
• MoreMenuCanvas → Share My Contact for your own node identity
• Contact action flows for sharing a peer's identity

ShareContactScreen options

• Copy Public Key — opens a text box with the full public key pre-filled
• Show QR Code — builds a meshcore://contact/add?... URI and opens ShareQrScreen with the QR
• Back

The share payload encodes the contact type (companion / repeater / room / sensor) automatically.

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3.5 Repeater and route screens

RepeatersScreen

Purpose List all discovered repeaters and enter repeater-specific actions.

Buttons/commands

• Refresh — request an updated repeater list and status from the node
• Back

Selecting a repeater row opens the appropriate action/login/telemetry context for that repeater.

RepeaterLoginScreen

Purpose Authenticate to a repeater when privileged operations require a login.

Buttons/commands

• Select
• Back
• Text entry dialogs: OK / Cancel

RepeaterLoggedInScreen

Purpose Post-login repeater operations — available once authenticated.

Buttons/commands

• Select
• Back

RepeaterPickerScreen

Purpose Pick a repeater when adding a hop to a trace path or contact route.

Buttons/commands

• Back

Selecting a repeater row appends that repeater as the next hop in the path being edited.

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3.6 Trace path and map screens

TracePathSelectScreen (manual path builder)

Purpose Build and modify a trace path manually by adding repeater hops, then run the trace.

Buttons/commands

• Run Trace — send the trace with the current forward path and navigate to results
• Add Repeater — open the repeater picker and append a hop to the path
• Remove Repeater — remove the selected or last hop
• Auto Return Path — automatically build the reverse/return path from the current forward path
• Enter Path Manually — open the hex editor for raw path bytes
• Reset Path — clear all configured hops and start fresh
• Back

TracePathResultScreen

Purpose Show the results of a completed trace in a readable timeline for the forward and return paths.

Buttons/commands

• Refresh — re-run the same trace and update the result display
• View on map — open MapViewCanvas with the trace path overlaid
• Back

UI details

• Header summary: total path distance first, then total hop count.
• Per-hop lines: SNR value + segment distance for each hop.
• Footer summary: Total Path Distance: ...

MapViewCanvas

Full interactive tiled map with two modes.

Normal map mode commands

• Select — interact with a selected node/contact/repeater marker
• Zoom + / Zoom - — zoom in and out
• My Location — center the map on your node's last known position
• Measure distance: ON/OFF — toggle distance measurement mode between two tapped points
• Trace Path • Using Map — switch into trace-pick mode to build a route visually
• Map Source — open the tile source selector
• Back

Trace-pick mode commands

• Run Trace — run the trace with the currently selected map-built path
• Add Repeater — add the next hop from the map
• Remove Last Repeater — undo the last added hop
• Auto Return Path — auto-generate the return path
• Reset Path — clear all hops and start over
• Zoom + / Zoom -
• My Location
• Map Source
• Back

What you can do on the map

• Pan by scrolling/dragging.
• Tap node, contact, and repeater markers to inspect their position and info.
• Measure straight-line distances between two points with the measurement toggle.
• Build a trace route visually by tapping repeaters in sequence, then run the trace directly from the map.

MapSourceForm

Purpose Configure which tile source the map uses.

Buttons/commands

• OK — save selected map source and return
• Cancel — discard changes and keep the previous configuration
• Preset options:
  • Lightweight - No Tiles — blank/minimal background, no network needed
  • External: SD Card — load tiles from a local SD card (good for offline use)
  • External: BGMountains — external tile set focused on mountain terrain (Bulgaria/regional)
  • Google: Roadmap
  • Google: Satellite
  • Google: Hybrid
  • Google: Terrain

What happens

• Selecting a preset fills in the tile URL/template field automatically.
• OK saves the selected source; the map immediately uses the new tiles.
• Cancel leaves the previous source unchanged.

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3.7 Diagnostics, settings, and info screens

NoiseFloorScreen

Purpose Live monitoring of the radio noise floor on the connected node.

Buttons/commands

• Back

Useful for checking RF environment quality — higher noise floor means more interference and reduced range.

ActivityLogScreen

Purpose View a real-time log of protocol and operational events — useful for debugging connectivity, tracing message flow, and understanding what the node is doing.

Buttons/commands

• Back

DeviceInfoScreen

Purpose Snapshot of connected node hardware and software state — battery level, firmware version, statistics.

Buttons/commands

• Refresh — fetch current values from the node
• Back

TelemetryResultScreen

Purpose Display decoded telemetry data from a node or repeater, plus the raw payload bytes for verification.

Buttons/commands

• Refresh — re-request telemetry and update the display
• Back

PingZeroHopScreen

Purpose Send a zero-hop ping to a node and display the round-trip result. Zero-hop means the ping goes directly to adjacent nodes without routing through repeaters.

Buttons/commands

• Back

SettingsScreen

Purpose View and modify node and app parameters from one unified place.

Buttons/commands

• Select — open the editor for the selected setting item
• Save — send updated values to the node
• Refresh — read current values from the node (overwrites local edits)
• Message settings — open MessageSettingsScreen
• Back

What happens

• Save pushes all modified settings to the node in one operation.
• Refresh re-reads settings from the node — useful after node-side changes or to discard local edits.

MessageSettingsScreen

Purpose Message history maintenance and storage visibility.

Buttons/commands

• Back

List actions

• Storage used: ... KB — tap to refresh and see current storage consumption
• Clear channel history — wipe all locally stored channel messages
• Clear DM history — wipe all locally stored direct message history

What happens

• Clear actions open a confirmation dialog (Yes / No).
• On Yes, the selected history is deleted and the storage usage figure is refreshed immediately.

NotImplementedScreen

Purpose Safe placeholder for features that are planned but not yet implemented.

Buttons/commands

• Back

What happens

• Shows a "coming soon / not implemented" heading and message.
• Used as a fallback so unfinished navigation paths don't crash or dead-end.

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3.8 Full UI coverage matrix

This matrix is a compact verification view: where each screen is opened from, what actions exist, and what the user gets next.

Screen	Entry point	Main commands/options	User outcome
ConnectScreen	App start / Connect To	Connect	Connects to node, then opens main menu
MainMenuScreen	Post-connect home	Select, Advert • Zero Hop, Advert • Flood, Disconnect/Connect To, More	Global navigation + advert/session control
MoreMenuCanvas	Main menu → More	Select, Back	Opens Add Contact/Channel, Share My Contact, Map, Tools, Settings, About, Exit
ToolsScreen	More menu → Tools	List select, Back	Opens trace/manual, trace/map, noise floor, activity log
ChannelListScreen	Main menu → Channels	Channel Info, Share with QR Code, Remove Channel, Back, list select	Opens chat/info/share/remove channel flows
ChannelScreen	Select channel row	Write, Back, Clear History, textbox Send	Public channel messaging
ChannelInfoScreen	Channel list → Channel Info	Copy (non-public), Back	Shows channel type/name/secret details
CreatePrivateChannelScreen	Add Channel → Create Private	Create, Back	Creates private channel
PrivateChannelSecretScreen	After private creation	Back	Shows generated secret to share with peers
AddChannelOptionsScreen	More → Add Channel	Create private, Join private, Join hashtag, Scan QR, Back	Adds channels using selected method
AddChannelFromQrScanScreen	Add Channel → Scan QR	Camera scan flow	Valid QR adds channel; invalid QR shows error
ShareQrScreen	Channel share / contact share	Back	Displays QR payload for scanning
ContactsScreen	Main menu → Contacts	Search, Write Message, Refresh, Back, list select	Opens DM or contact actions
DMScreen	Contacts/Favorites/actions	Write, Back, Clear History, Set Path, Reset Path, textbox Send	Direct messaging + per-contact route control
ContactActionsScreen	Contact list row select	Action list, Back	Contact-level tools (details/share/favorite/telemetry/trace/map/remove)
ContactDetailsScreen	Contact actions	Copy Key, Copy Coordinates, Back	Read-only identity/location details
PathListScreen	DM → Set Path	Add hop, Remove hop, Enter Path Manually, Save, Reset Path, Back	Edit/save/reset contact route bytes
RepeaterPickerScreen	Path/trace add hop	list select, Back	Chooses repeater hop to append
AddContactOptionsScreen	More → Add Contact	Manual add, Scan QR, Back	Adds contact via form or QR scan
ManualAddContactScreen	Add Contact → Manual	OK, Back	Adds contact by name + public key
AddFromQrScanScreen	Add Contact → Scan QR	Camera scan flow	Valid QR adds contact; invalid QR shows error
ShareContactScreen	Contact actions / Share My Contact flow	Copy Public Key, Show QR Code, Back	Shares identity as text key or QR payload
FavoritesScreen	Main menu → Favorites	Write Message, Remove from Favorites, Back	Fast access to frequent contacts
NotificationsScreen	Main menu → Notifications	Open, Back	Jumps to destination screen for notification
RepeatersScreen	Main menu → Repeaters	Refresh, Back, list select	Opens repeater actions/login/telemetry context
RepeaterLoginScreen	Repeater action requiring auth	Select, Back (+ dialog OK/Cancel)	Login/session start for repeater
RepeaterLoggedInScreen	After repeater login	Select, Back	Repeater post-login operations
TracePathSelectScreen	Tools → Trace Path Manual	Run Trace, Add Repeater, Remove Repeater, Auto Return Path, Enter Path Manually, Reset Path, Back	Manual path build + trace run
TracePathResultScreen	Trace run result	Refresh, View on map, Back	Timeline SNR+distance + map transition
MapViewCanvas	Tools map / map entry points	Mode-dependent commands (zoom, source, location, trace controls)	Map inspect + map-based trace workflow
MapSourceForm	Map view → Map Source	OK, Cancel, template presets	Saves/updates map tile source
NoiseFloorScreen	Tools → Noise Floor	Back	Live noise-floor display
ActivityLogScreen	Tools → Activity Log	Back	Runtime/protocol event log
DeviceInfoScreen	Settings/device action	Refresh, Back	Live readings and device/node summary
TelemetryResultScreen	Telemetry request result	Refresh, Back	Decoded telemetry + raw payload
PingZeroHopScreen	Ping action flows	Back	Zero-hop ping result visualization
SettingsScreen	More → Settings	Select, Save, Refresh, Message settings, Back	Node/app setting management
MessageSettingsScreen	Settings → Message settings	storage row tap, clear channels, clear DMs, Back	History maintenance and storage tracking
AboutScreen	More → About	Back	App/project info screen
NotImplementedScreen	Placeholder routes	Back	Safe fallback for unfinished features

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4) UI screenshots

All screenshots below are grouped to match the same flow as section 3) and aligned in a fixed 3-column gallery for consistent viewing.

4.1 Main navigation (3.2)

`MainMenuScreen` (1)	`MainMenuScreen` (2)	`MainMenuScreen` (3)
`MoreMenuCanvas`	`ToolsScreen`	`AboutScreen`

4.2 Messaging: channels and DMs (3.3)

`ChannelListScreen`	`ChannelScreen`	`DMScreen` (compose)
`ContactsScreen` (1)	`ContactsScreen` (2)	`PathListScreen`

4.3 Add/share flows (3.4)

`AddContactOptionsScreen`	`AddChannelOptionsScreen`	`MapSourceForm` (preset)
`ContactDetailsScreen`	`MapViewCanvas` (contact 1)	`MapViewCanvas` (contact 2)

4.4 Repeaters and route tools (3.5)

`RepeatersScreen`	`RepeaterLoginScreen`	`RepeaterLoggedInScreen`
`TelemetryResultScreen` (repeater)	`TelemetryResultScreen` (contact)	`PingZeroHopScreen`

4.5 Trace path and map (3.6)

`MapViewCanvas` trace (1)	`MapViewCanvas` trace (2)	`MapViewCanvas` trace (3)
`MapViewCanvas` trace (4)	`MapViewCanvas` measure (1)	`MapViewCanvas` measure (2)

4.6 Diagnostics, settings, and info (3.7)

`NoiseFloorScreen`	`ActivityLogScreen`	`DeviceInfoScreen`
`SettingsScreen`	`MapSourceForm`	`AboutScreen`

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5) What happens in the background

From the user's perspective:

• Incoming frames update chats, contacts, notifications, and dashboard info automatically.
• The UI refreshes asynchronously so it stays responsive while waiting for node responses.
• Request flows (trace/ping/telemetry/login) are handled by dedicated services that track pending state and support refresh/retry behavior.

Key background service groups:

• ZeroHopPingService
• TracePathPingService
• TelemetryRequestService
• LoginRequestService
• DmSendManager

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6) Build and run

This is a Java ME app — not standard desktop Java.

1. Import the project sources into a Java ME capable SDK or IDE (e.g. NetBeans with the Mobility Pack, or a compatible toolchain).
2. Set the MIDlet entry point to MeshCore.
3. Ensure network (TCP) and RMS (storage) permissions are declared in the manifest/JAD file.
4. Build the JAR/JAD.
5. Deploy to a device or run in an emulator.

Running on a physical device

Tested on Nokia Asha 210. Any MIDP 2.0 / CLDC 1.1 handset with Wi-Fi TCP and sufficient RMS storage should work.

Running on desktop with KEmulator

KEmulator (kemnnx64) allows you to run the app on Windows, Linux, and macOS without a physical device.

1. Download the latest KEmulator release for your OS from the link above.
2. Launch KEmulator.
3. Load the built JAR file via the emulator's open/load function.
4. Ensure the emulator has network access to the same local network as your MeshCore node.
5. The app will run with full UI and TCP connectivity.

KEmulator is useful for development, testing, and demonstration when a Java ME handset is not available.

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7) Roadmap TODO

• Multibyte path support
• Repeater management
• Time Zone configuration
• Bug fixes
• Refactor (where needed)

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8) Quick troubleshooting

• Cannot connect: verify the host/IP and port, and confirm the phone/emulator and node are on the same local network.
• No contacts or repeaters visible: wait for the initial sync to complete and use the Refresh action on the relevant screen.
• Trace shows incomplete distance: some hops may not have advertised GPS coordinates — distance is only shown for hops with location data.
• Map looks empty or wrong: check the map source template in MapSourceForm, and confirm network or SD card tile availability.
• KEmulator network issues: make sure the emulator's network interface can reach the MeshCore node's IP/port — check firewall rules on the host machine.