USBC M2E HaLow Adapter

USB-C to M.2 Key-E HaLow adapter

USB 2.0 over a USB-C receptacle to an M.2 2230 Key-E socket, for the Gateworks GW16170 (Morse Micro MM8108-M20) Wi-Fi HaLow card. 56.5 x 40.5 mm, 2-layer (JLCPCB JLC0216A), single-sided assembly.

Status: Rev A is built and works as designed (boards assembled by JLCPCB, confirmed by the author on 2026-09-29). The project is closed; no Rev B is planned. Test procedure: docs/Test_Procedure.md. Pre-fabrication review: docs/Design_Review_2026-09-20.md.

Only USB D+/D- (M.2 pins 3 and 5), 3.3 V and ground go to the card. W_DISABLE1# (the card's reset) and W_DISABLE2# (wake) are left open on purpose: the card has its own pull-ups, and its reset pin uses a power-on RC that an external pull-up would defeat.

Bill of materials

Full BOM with notes and the parts you supply yourself: BOM.md. The CSV that went to JLCPCB: fab/USBC_M2E_HaLow_Adapter_bom.csv.

You also need the GW16170 card, an M2 x 3–4 mm screw, an MMCX antenna or pigtail, and a short 3 A USB-C cable on a port that can supply about 0.9 A.

How it was made

Everything is generated from Python. Edit the scripts, not the KiCad files. Run with KiCad's Python:

"C:\Program Files\KiCad\10.0\bin\python.exe" generate_schematic.py --force
"C:\Program Files\KiCad\10.0\bin\python.exe" autoplace.py . --floorplan
"C:\Program Files\KiCad\10.0\bin\python.exe" autoplace.py . --place --force
"C:\Program Files\KiCad\10.0\bin\python.exe" setup_fab.py
"C:\Program Files\KiCad\10.0\bin\python.exe" route_board.py
"C:\Program Files\KiCad\10.0\bin\python.exe" drc_report.py
"C:\Program Files\KiCad\10.0\bin\python.exe" check_m2_clearance.py
"C:\Program Files\KiCad\10.0\bin\python.exe" build_package.py

--place resets every unlocked footprint. Designators moved by hand in KiCad are detected and kept (.pcbgen-refs.json). route_board.py redraws every track, via and pour each time it runs. build_package.py writes fab/ and refuses to run unless DRC is clean.

Mechanical facts, from the MLD-NGFF-E-4.2H drawing:

• the card extends from the even-pin / locating-peg side of the socket;
• the card stop is 1.75 mm behind the pegs, so the 2230 notch is 29.75 mm from the socket centre;
• the card's underside is 2.52 mm above the board; parts under it must be 0.90 mm or lower.

JLCPCB: setup_fab.py writes their 2-layer rules into the project and into USBC_M2E_HaLow_Adapter.kicad_dru, with the source pages and date in its docstring. The USB pair is 0.3345 / 0.1524 mm with ground pour 0.2032 mm either side, from JLCPCB's own calculator for stackup JLC0216A. JLCPCB does not test impedance on 2-layer boards. jlc_rotations.json holds the placement-file corrections with the evidence for each.

Repository contents

• USBC_M2E_HaLow_Adapter.kicad_*: the KiCad 10 project, schematic, routed board and custom design rules.
• fab/: the package sent to JLCPCB for Rev A (gerbers zip, BOM, placement file, order notes).
• docs/: schematic PDF, renders, copper images, the pre-fabrication design review and the board test procedure.
• library/: project symbols, footprints and 3D models.
• *.py: the generators. schlib.py, subcircuits.py, pcblib.py, autoplace.py, recipes.py and jlc_cpl.py are copies of the libraries the project was generated with.
• Vendor datasheets are not included.

Licence

Copyright Diode663 2026.

Hardware (the KiCad project, schematic, board, the project's own symbols and footprints, fabrication outputs and documentation): this source describes Open Hardware and is licensed under the CERN-OHL-P v2. You may redistribute and modify this source and make products using it under the terms of the CERN-OHL-P v2 (https://ohwr.org/cern_ohl_p_v2.txt), a copy of which is in LICENSE. This source is distributed WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY, SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE. Please see the CERN-OHL-P v2 for applicable conditions. Source location: https://github.com/Diode663/USBC_M2E_HaLow_Adapter

Software (every *.py file): MIT, see LICENSE-MIT.

Not covered by either licence — third-party material, included for convenience and owned by its respective rights holders:

• footprints and 3D models obtained from LCSC / EasyEDA with easyeda2kicad: library/HaLowAdapter.pretty/CONN-SMD_MLD-NGFF-E-4.2H.kicad_mod, IND-SMD_L7.2-W6.6_GPSR07X0.kicad_mod, SMTSO_M2_H2.5_SMTSOM225BTR.kicad_mod, and in library/HaLowAdapter.3dshapes/ the USB-C_SMD-TYPE-C-31-M-12_1, IND-SMD_L7.2-W6.6-H3.0_GPSR07X0 and SMD_BD5.6-D3.6 models;
• USB_C_Receptacle_HRO_TYPE-C-31-M-12.kicad_mod and the M.2 socket symbol, which are modified copies from the KiCad libraries (CC-BY-SA 4.0 with the KiCad library exception).

Gateworks, Morse Micro, JLCPCB and the part manufacturers are not affiliated with this project.