A standalone Meshtastic communicator for M5Stack CardPuter
Plai is the Ukrainian word for a mountain trail — a reliable path for your data to travel when you're off the beaten track.
Most Meshtastic nodes rely on a phone via BLE or WiFi. Plai takes a different approach: it turns the CardPuter into a self-contained messaging terminal. No phone required — just you, the LoRa CAP, and the keyboard.
- Full standalone operation — No WiFi, no BLE. Direct LoRa mesh communication with on-device UI.
- Unlimited message history — The entire profile, message history, and node database live on the SD card. Storage is limited only by your card size.
- Swap and survive — Reboot or switch firmwares without losing your place in the mesh. Everything persists on SD.
- Pro navigation — PgUp / PgDown / Home / End for fast scrolling through long threads and node lists.
- Debug tools — Built-in Packet Monitor (last 50 packets) and Trace Route history (last 50 attempts per node).
- Custom alerts — Individual channel notifications with distinct sounds.
- Display sleep — Screen turns off when idle to save power; wake on keypress or radio activity.
- Fully compatible with Meshtastic network v2.7+
- Ping auto-reply: respond automatically when someone #ping's the channel
- New node greetings: send a welcome broadcast to the channel and/or a Direct Message when a new node appears
Full node management with up to 1000 nodes persisted on SD card.
- Node list with signal strength, hops, battery, role, encryption indicators
- 8 sorting modes (name, role, signal, hops, last heard, favorites first, etc.) hotkey for sorting [1..8], [TAB] to select sorting mode
- Relay node display — see which node relayed each packet hotkey [R] to jump to relay node
- Favorite marking and quick-jump navigation hotkey [F] to toggle favorite
- Ignore nodes — mark nodes as ignored to filter their traffic hotkey [I] to toggle ignored
- Node detail view with hardware model, position, and metrics hotkey [Fn] + [ENTER] to open
- Direct Messages hotkey [ENTER] to open
- Exchange node info hotkey [N] — send node info request to selected node
- Exchange position hotkey [P] — send position request to selected node
- Traceroute hotkey [T] to open recent traceroute logs. [Fn] + [T] to start traceroute immediately
- Direct messaging with delivery status (pending → sent → ACK → delivered → failed)
- Channel invitation hotkey [I] — invite the node to a channel (sends
#invite name=keyDM) - Full keyboard input with Cyrillic layout support
- File-backed message history on SD card
- Clear chat hotkey [BACKSPACE] to clear all messages
- Hold [CTRL] to display message info (timestamp, will be more soon...)
- Traceroute with hop-by-hop detail, round-trip duration, and SNR at each hop
- Last 50 traceroute attempts stored per node
- Visual route map with color-coded signal quality
- Press [T] to start new traceroute
Dedicated view of all your favorite nodes, stored persistently on SD card (favorites.dat).
- Open — [Fn] + [F] from node list
- Add/remove — [F] on a node in the main list toggles favorite status (shown in gold)
- Navigation — Arrow keys, [PgUp]/[PgDown] for page scroll, [Fn]+[↑] Home / [Fn]+[↓] End
- Jump to node — [ENTER] selects the highlighted favorite and returns to node list with that node focused
- Remove — [DEL] removes the selected favorite; [Fn]+[DEL] clears all favorites
- Favorites survive node database resets and firmware updates (file-backed)
Manage ignored nodes whose traffic is filtered at the mesh layer. Packets from ignored nodes are dropped before processing.
- Open — [Fn] + [I] from node list
- Add/remove — [I] on a node in the main list toggles ignored status (shown in red)
- Same navigation and shortcuts as favorites — [ENTER] jump to node, [DEL] remove selected, [Fn]+[DEL] clear all
- Ignored nodes stored in
ignorelist.daton SD; survives resets and updates
Multi-channel group chat supporting up to 8 channels.
- Channel list with unread message counts
- Channel hash — Each channel shows its hash (e.g.
#A3) derived from name and PSK. Lets you see how the hash depends on settings and correlate packets in Monitor (packets display the same#XXchannel byte). - Channel creation hotkey [Fn] + [SPACE] to open channel creation dialog
- Channel editing hotkey [Fn] + [ENTER] to open channel editing dialog
- Channel chat hotkey [ENTER] to open channel chat
- Individual notification sounds per channel
Many of us send "test test" and get no reply. Now Plai can reply automatically when you add #ping in your channel message — no more wondering if anyone's listening.
- #ping auto-reply — Add
#pinganywhere in a channel message; Plai responds with a configurable template. Macros:#short,#long,#id,#hops,#snr,#rssi - New node greetings — When a node appears for the first time (after receiving their NodeInfo), Plai can send a welcome broadcast to the channel and/or a Direct Message. Same macros apply.
- Per-channel settings — Each of the 8 channels has its own greeting and ping reply templates.
There are predefined templates for the greetings and ping reply. You can use them or enter your own custom text, holding [Fn] key.
Example: "Look who is here! #long, welcome to HAM Community of Smartwill city. I can see you with #hops hops #snr/#rssi"
Share a channel with another node via Direct Message.
- Sending — In DM with a node, press [I]. Select a channel; Plai sends a DM in format
#invite name=base64_psk(name max 11 chars, key base64-encoded). If the node has no public key, a confirmation is shown before sending unencrypted. - Receiving — Enable Settings → Security → Invitations. When a DM starts with
#inviteand matches#invite channel_name=base64_psk, Plai creates a new channel at the first free slot. Duplicate channels (same name and key) are ignored. - Requires at least one free channel slot to accept an invitation.
Live radio packet feed for debugging and network analysis.
- Real-time TX/RX packet display with port labels (TEXT, POS, NODE, TELE, ROUT, TRAC, etc.)
- Channel hash (
#XX) shown per packet — matches the hash in Channels for easy correlation - Color-coded direction, node badges, and SNR indicators
- Color-coded packet ID for easy relay identification
- From/To node name resolution from NodeDB
- Scrollable packet list with detail drill-down view
- Last 50 packets in a static ring buffer
- Select first item for autoscroll
Complete device and mesh configuration stores in NVS. You can export and import settings to SD card for backup and restore it later.
Node database and chat history are stored on SD card and not affected by firmware updates.
- System: brightness, volume, timezone
- LoRa: region, modem preset, TX power, hop limit
- Security: channel PSK management, invitations (auto-add channels from
#inviteDMs) - Node info: name, short name, role
- Position: GPS enable, fixed position, broadcast interval. GPS time sync: callback-based; system clock updated from GPS only when drift exceeds 60 seconds
- Telemetry: device metrics broadcast
- Export/Import settings to SD card
- Clear all nodes
| Component | Description |
|---|---|
| M5Stack CardPuter ADV | ESP32-S3 portable terminal with keyboard |
| LoRa CAP | M5Stack SX1262 LoRa module (868/915 MHz) |
| SD Card | For profile, messages, and node database |
Beta version is available in M5Apps (Installer → Cloud → Beta tests).
Standalone version will be added to M5Burner soon.
Look for M5Apps in M5Burner.
Built from scratch on ESP-IDF — not a fork of the Meshtastic firmware.
- Encryption: AES-CTR with channel PSK, X25519 public-key cryptography
- Multi-channel: Up to 8 channels with individual PSKs
- Routing: Hop-limit flooding (1–7 hops) with Meshtastic-compatible duplicate detection
- Reliability: ACK/NACK with automatic retries, implicit ACK via rebroadcast
- Priority TX queue: ACK > Routing > Admin > Reliable > Default > Background
- Duty cycle: Channel and air utilization tracking
- Multi-region: US, EU_433, EU_868, CN, JP, ANZ, KR, TW, RU, IN, and more
- Packet encoding: Nanopb (Protocol Buffers) for full Meshtastic wire compatibility
- ESP-IDF v5.5.x
- ESP32-S3 target
idf.py set-target esp32s3
idf.py build
idf.py -p COMx flash monitorHardware components can be individually toggled via menuconfig:
idf.py menuconfig
# Navigate to: HAL Configuration| Option | Default | Description |
|---|---|---|
HAL_USE_DISPLAY |
on | ST7789 display via LovyanGFX |
HAL_USE_KEYBOARD |
on | Keyboard input (requires I2C) |
HAL_USE_RADIO |
on | SX1262 LoRa radio |
HAL_USE_SDCARD |
on | SD card (FAT) |
HAL_USE_GPS |
on | ATGM336H GPS |
HAL_USE_SPEAKER |
on | I2S audio output |
HAL_USE_LED |
on | WS2812 RGB LED |
HAL_USE_BAT |
on | Battery voltage monitor |
HAL_USE_I2C |
on | I2C master bus |
HAL_USE_BUTTON |
on | Home button |
HAL_USE_USB |
on | USB MSC host |
HAL_USE_WIFI |
on | WiFi |
HAL_USE_BLE |
on | Bluetooth Low Energy |
Plai/
├── main/
│ ├── apps/ # Application layer
│ │ ├── launcher/ # Home screen & system bar
│ │ ├── app_nodes/ # Node list, DM, traceroute
│ │ ├── app_channels/ # Channel group chat
│ │ ├── app_monitor/ # Live packet feed
│ │ ├── app_settings/ # Configuration UI
│ │ └── utils/ # Shared UI components
│ ├── hal/ # Hardware Abstraction Layer
│ │ ├── hal.h # Base HAL class
│ │ ├── hal_cardputer.* # M5Cardputer implementation
│ │ ├── display/ # LovyanGFX display driver
│ │ ├── keyboard/ # TCA8418 / IOMatrix drivers
│ │ ├── radio/ # SX1262 LoRa driver
│ │ └── ... # GPS, speaker, LED, battery, etc.
│ ├── mesh/ # Meshtastic protocol
│ │ ├── mesh_service.* # Core mesh service
│ │ ├── node_db.* # Node database (SD-backed)
│ │ ├── mesh_data.* # Message store & packet log
│ │ └── packet_router.* # Priority TX/RX queues
│ ├── meshtastic/ # Protobuf definitions (Nanopb)
│ ├── settings/ # NVS settings with cache
│ └── main.cpp # Entry point
├── components/
│ ├── LovyanGFX/ # Display graphics library
│ ├── mooncake/ # App framework
│ └── Nanopb/ # Protocol Buffers
└── Kconfig.projbuild # menuconfig HAL options
- Fonts: efont Unicode bitmap fonts from the Linux distribution
- Icons: Free icons by Icons8
- Platform: M5Stack M5Cardputer
This project is licensed under the GNU General Public License v3.0 — see LICENSE for details.
