Vicliu624’s Trail Mate is an open-source firmware developed for off-grid communication and GPS coordinates sharing. Utilizing the Meshtastic, MeshCore, and other projects, it is tailored for ESP32 handheld devices like LILYGO’s T-LoRa Pager or M5Stack’s Tab5 with a LoRaWAN module.
The firmware provides a fixed north-up GPS map, enables direct LoRa text messaging through Meshtastic or MeshCore mesh networks without a smartphone, and focuses on stability, efficiency, and interoperability over feature density.
Trail Mate user interface highlights:
- Simple main menu with four icons: GPS, LoRa chat, tracker, and system utilities.
- GPS map
- Fixed North-Up map orientation (no rotation)
- Fully offline map rendering from SD card tiles (png/jpg files)
- Three switchable base layers: OSM / Terrain / Satellite
- Optional contour overlay for terrain shape awareness
- Real-time position marker for the current GPS fix
- Discrete zoom levels optimized for embedded systems
- Simple breadcrumb trails for path awareness
- Fast in-page layer switching via map layer menu (no page restart)
- GNSS Sky Plot
- Real-time sky plot of visible satellites (azimuth/elevation)
- SNR status and constellation coloring (GPS/GLONASS/Galileo/BeiDou)
- Clear indication of satellites used in the current fix
- Summary of USE/HDOP/FIX for fast diagnostics
- Energy Sweep (Sub-GHz Scan) provides a fast Sub-GHz occupancy view for channel planning in the field.
- LoRa Chat (Meshtastic + MeshCore Compatible) with English and Chinese text support, Bluetooth connectivity to mobile companion apps,
- SSTV Receiver (Slow-Scan TV) to receive audio and decode to images on-device
- Contacts – Shows discovered nodes, recent activity, and quick actions to jump into direct or team conversations.
- Data Exchange – A PC Link connects the device to a host computer and exposes a structured HostLink stream for real-time APRS/iGate integration, diagnostics, and data capture.
- Team Mode – Designed for small groups that are physically together, the handhelds pair over ESP-NOW at close range to exchange a team key, then all team operations run over LoRa.
- Track Recording & Route Following
- Walkie Talkie
- FSK + Codec2 voice walkie-talkie
- Half-duplex PTT (press to talk/release to listen)
- Jitter buffering and fixed playback cadence for stability
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