4 layers60 × 130 mm
Parsnip
LimesKey/parsnip-node
A portable LoRa communicator. Custom 4-layer PCB (ESP32-S3 + E22P-915M30S LoRa + NEO-M9N GNSS), designed in KiCad for 915 MHz.
481 parts6
2 layers40 × 30 mm
Selftest
LimesKey/parsnip-node6A portable LoRa communicator. Custom 4-layer PCB (ESP32-S3 + E22P-915M30S LoRa + NEO-M9N GNSS), designed in KiCad for 915 MHz.
- Size
- 40 × 30 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 20
- Nets
- 32
- Pads
- 40
- Tracks, vias
- 4, 2
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20241229)
- Created
- 1 Jun 2026
- Updated
- 3 Nov 2026
Overview
Selftest is an open-source printed circuit board by LimesKey, from the LimesKey/parsnip-node repository on GitHub. It is a 2-layer board of 40 × 30 mm with 20 parts on 32 nets, routed with 4 tracks and 2 vias.
Its parts include 8 capacitors, 3 resistors, 3 connectors, 1 IC and 1 diode. It belongs with the radio and wireless boards and the ESP32 boards of this library.
README
README.mdparsnip-node
A battery-powered, portable Meshtastic/Meshcore node built around the ESP32-S3, an Ebyte E22P-915M30S LoRa front end, and a u-blox NEO-M9N GNSS receiver. Designed in KiCad, it targets 915 MHz operation in Canada under ISED RSS-247.
Overview
The goal is a self-contained LoRa node that pairs one of the longest range, best value LoRa modules, with an accurate GNSS reciever, running off two 21700 cells in series, to connect to other people on the LoRa mesh network community.
Schematic - v2
GNSS / active antenna |
LoRa front end |
Power rails |
Charger / BMS |
USB-C / PD |
Peripherals |
PCB - v2
3D Render - v2
In the field - v1
Assembled board |
Outdoor testing |
Outdoor testing, back |
Hardware
| Part | Price |
|---|---|
| JLCPCB PCB w/ Assembly (to-be changed BOM) | $1098.04 CAD (est) |
| 21700 Cells 18650batterystore.com | $40 CAD |
| 3.7" E-Ink AliExpress | 24$ CAD |
Board
- 4-layer with ENIG, 60 x 130 mm
- JLCPCB
JLC04161H-7628stackup, 2 oz copper outer, 2 oz copper inner - 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
ESP32-S3 GPIO pin map
Host: ESP32-S3-WROOM-1-N16R8 (U1). GPIO numbers are ESP32-S3 GPIO, not module pins.
LoRa - E22P-915M30S (U12)
| Signal | GPIO |
|---|---|
| NSS | 10 |
| SCK | 12 |
| MOSI | 11 |
| MISO | 13 |
| BUSY | 14 |
| DIO1 | 4 |
| NRST | 40 |
| EN | 41 |
GNSS - NEO-M9N (U9)
| Signal | GPIO |
|---|---|
| TXD | 1 |
| RXD | 2 |
| TIMEPULSE | 3 |
| EXTINT | 48 |
| SDA | 8 |
| SCL | 9 |
Other peripherals
| Function | GPIO |
|---|---|
| I2C SDA | 8 |
| I2C SCL | 9 |
| I2C IRQ | 7 |
| E-Ink BUSY | 5 |
| E-Ink RESET | 6 |
| E-Ink D/C | 18 |
| E-Ink CS | 17 |
| Bus CS | 38 |
| USB D- / D+ | 19 / 20 |
| UART0 TX / RX | 43 / 44 |
| RTC 32 kHz xtal | 15 / 16 |
| BOOT | 0 |
| eFuse PG | 39 / 42 |
| EMI osc gate | 47 |
| Level shifter | 46 |
| Load switch | 21 |
| PSRAM (reserved) | 35 / 36 / 37 |
| VDD_SPI (reserved) | 45 |
Firmware
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/parsnip-node.gitParts
20| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | 10k | test:FP | C9, R1, R2, R9, R10, R11 |
| 2 | 0R | test:FP | R4, R5 |
| 2 | HDR | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J1, J3 |
| 1 | 100nF | test:FP | C1 |
| 1 | 1k | test:FP | R3 |
| 1 | 1uF | test:FP | C2 |
| 1 | 2.2uH | Inductor_SMD:L_4x4mm | L1 |
| 1 | 32.768kHz | Crystal:Crystal_SMD_3215-2Pin_3.2x1.5mm | Y1 |
| 1 | Conn_Coaxial | Connector_Coaxial:U.FL_Hirose_U.FL-R-SMT-1_Vertical | J2 |
| 1 | LED | test:FP | D1 |
| 1 | MCU_OK | test:FP | U1 |
| 1 | MountingHole | MountingHole:MountingHole_2.2mm_M2_DIN965_Pad | H1 |
| 1 | TP | TestPoint:TestPoint_Pad_D1.5mm | TP1 |
Questions
How big is the Selftest PCB?
It measures 40 × 30 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Selftest use?
20 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Selftest KiCad files?
From the LimesKey/parsnip-node repository on GitHub, at the commit this page was made from: the board is code/claude/kicad-review/references/selftest.kicad_pcb and its schematic block_diagram.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Selftest design in my own project?
Its repository states no licence, so its author keeps all rights: ask LimesKey before reusing the design.
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A portable LoRa communicator. Custom 4-layer PCB (ESP32-S3 + E22P-915M30S LoRa + NEO-M9N GNSS), designed in KiCad for 915 MHz.
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