A battery-powered, portable Meshtastic mesh node built around a Seeed XIAO ESP32-C6, an Ebyte E22P-915M30S LoRa front end, and a u-blox NEO-M9N GNSS receiver. Designed from scratch in KiCad and fabricated at JLCPCB, it targets 915 MHz operation in Canada under ISED RSS-247.
The goal is a self-contained Meshtastic node that pairs one of the longest range, best value LoRa modules, with an accurate GNSS reciever, running off a single 18650 cell, and connecting to the Canadian Meshtastic community.
Assembled board |
Outdoor testing |
Outdoor testing, back |
| Function | Part | Notes |
|---|---|---|
| MCU / radio host | Seeed XIAO ESP32-C6 | Used as an SMD/castellated module for easy soldering |
| LoRa | Ebyte E22P-915M30S | SX1262 + external PA, up to 30 dBm, needs 5 V for full output |
| GNSS | u-blox NEO-M9N | GPS / GLONASS / Galileo / BeiDou |
| Boost | TI TPS61033 | While expensive, it's quite powerful and compact |
| Power mux | TI TPS2116 | USB / battery source selection |
| Battery protection | TI BQ29700 | Single-cell protection |
| Reverse polarity | AO3401A P-channel MOSFET | Input protection |
| Cell | 18650 3500mAh Li-ion | Single cell |
- 4-layer, 55 x 100 mm
- JLCPCB
JLC04161H-7628stackup, 1 oz copper - L1-L2 prepreg 0.2104 mm, Dk 4.4
- RF: 0.36mm trace width for ~50 Ω CPWG on this stackup, ground rails stitched with 0.3 mm / 0.6 mm vias at roughly 1.5 to 2 mm pitch
| Signal | GPIO |
|---|---|
| NSS | 21 |
| SCK | 19 |
| MISO | 20 |
| MOSI | 18 |
| DIO1 | 1 |
| BUSY | 7 |
| NRST | 16 |
| EN | 17 |
The E22P EN (module pin 6) is held high for both RX and TX. The T/R switch (pin 7) is driven automatically from the SX1262 DIO2 line, so the firmware sets setDio2AsRfSwitch(true).
Firmware is a Meshtastic fork tracked as the firmware submodule (LimesKey/firmware). Development uses VS Code with the pioarduino extension, which Meshtastic pins for ESP32-C6 / Arduino-ESP32 3.x support. A device variant declares the pin map above and the PA control lines so TX actually keys up. Unfortunately there are some extensive changes to the Meshtastic firmware in order to incorporate a SPI GNSS module, as this is not natively supported by Meshtastic.
git clone --recurse-submodules https://github.com/LimesKey/limeskey-node.git