vicliu624’s Trail Mate is an open-source firmware for off-grid communication and GPS coordinates sharing, leveraging the Meshtastic, MeshCore, and other projects, and designed for ESP32 handhelds such as LILYGO’s T-LoRa Pager or M5Stack’s Tab5 with a LoRaWAN module.
The Trail Mate firmware provides a fixed north-up GPS map, direct LoRa text messaging through Meshtastic or MeshCore mesh networks without relying on a smartphone, and prioritizes 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 (See video below at the end of the article)
- 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

The following hardware platforms are currently supported or under development:
- PlatformIO/Arduino-based targets
- LILYGO T-LoRa Pager (SX1262) – Reference platform, default environment; SX1280 variant is also supported, but less tested
- LILYGO T-Deck – Primary validation target
- GAT562 Mesh EVB Pro – Resource-constrained target, some features are trimmed
- LILYGO T-Deck Pro – Under development
- LILYGO T-Watch S3 – Experimental target
- Targets using the ESP-IDF framework
- M5Stack Tab 5 – Main large-screen IDF bring-up target. The shared shell runs, hardware-specific work is in progress
- LILYGO T-Display P4 – Alternative IDF development device
That means the LILYGO T-LoRa Pager is the preferred platform. It can be purchased for just under $100 on AliExpress and on Amazon.

You’ll find the code and resources to get started on GitHub, with everything released under an AGPLv3 license. These days, many software projects rely on AI coding, even the Linux kernel, and Trail Mate is no different:
All code in Trail Mate is 100% generated by AI under human guidance. The project itself is a long-term experiment in human–AI collaboration for real engineering systems.
LILYGO installed Trail Mate on the T-LoRa Pager and you can watch a short SSVT image transmission demo in the video embedded below.
#LILYGO #LoRa #Meshtastic #OpenSource– perfect for off-grid messaging & outdoor adventures!
Open-source & ready to flash → https://t.co/d5JG1wVlws
Thanks for the great work! Who’s building next?
🚀 Exciting community project alert!
T-LoRa Pager running Trail Mate firmware… pic.twitter.com/KugejoIrvu— LILYGO (@lilygo9) February 10, 2026

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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