Wireless series Smoothieboard-side master

Host-side radio endpoint for a deliberately configured remote-I/O protocol; it is not a transparent wire replacement.

Development status

Baseline documentation snapshot: 2026-10-11, before the requested connector/protection/usability revision program. New revision features require their own reviewed source and qualification evidence.

This page documents an unqualified engineering study, not a released or tested product. Saved CAD, renders and automated checks do not establish a safe assembly, compatible cable, firmware support or a usable current rating.

Board-specific qualification limits: Retained ERC/DRC/opens/parity and assembly-shape checks zero;88 checklist items unsigned. Firmware OE/link-loss, partial-power, RF, host budget, debug, exact stock and physical qualification open.

Interfaces and wiring

Inputs

  • Mode-dependent canonical Gadgeteer socket
  • Optional local provisioning control and radio packets

Outputs

  • nRF24 radio link
  • Mode-dependent reconstructed local signals
  • Status LEDs

Connection contract

The canonical repository connector contract is pin 1 = +3.3 V, pin 2 = +5 V, pin 10 = GND. Current Smoothie V2 Prime web material appears to describe a conflicting header assignment; the physical target header must be continuity-checked against its authoritative schematic before KiCad release. The table below expresses design intent against the repository’s canonical contract, not proof of the live board pinout.

Pin Canonical role Assigned function
1 +3.3V +3.3 V rail
2 +5V +5 V rail
3 GPIO! / type-specific Mode GPIO0 / provisioning GPIO
4 type-specific Mode TX or GPIO1
5 type-specific Mode RX or GPIO2
6 type-specific Mode GPIO3 / CTS / CS
7 type-specific Mode GPIO4 / RTS / MOSI / PWM
8 type-specific Mode GPIO5 / SDA / MISO
9 type-specific Mode GPIO6 / SCL / SCK
10 GND Ground

Power off before connecting or changing jumpers. Verify pin 1, signal direction, supply voltage and ground at both ends of every cable. A mechanically fitting connector is not proof of electrical compatibility. If a host pin mapping or current allocation remains unresolved in the design record, do not connect the board until it is resolved.

Electrical design requirements

The following are specification requirements or study assumptions; they are not measured operating ratings. A newer selected-revision note takes precedence over historical draft options.

  • Radio and MCU shall operate from a regulated 3.3 V rail
  • Antenna layout shall follow the selected module or IC reference design
  • Logic levels at the host socket shall remain 3.3 V compatible
  • No safety-critical motion, heater, or laser-enable function is permitted without independent safety validation

Protection in the design record

The design describes the following protection intent. Check the selected schematic and remaining qualification gates before relying on it:

  • Series resistance and ESD protection on every off-board signal
  • Brownout detector and watchdog must force safe state
  • Reverse-current isolation between selected supply sources

Selected component architecture

See current review. Retain v10 ATSAMD21E18A/nRF24L01+ interoperability and already adopted SN74CB3Q3245 bus isolation. Integrated nRF52832 requires unsupplied protocol/firmware migration. Existing V1-compatible bypass consolidation retained; no IC-stock successor. Current selected v10; retained native/stock/physical qualification limits remain explicit.

Configuration and commissioning

Use the configuration and firmware contract for the exact selected revision. Do not copy another module’s socket assignments or assume that an unused pin is available. First-article work must verify source selection, reset/unplug behavior, cable orientation and the actual load or sensor interface before normal operation.

Requested connector and usability upgrades

The following are requirements for the next design iterations; this page does not claim they are already fitted:

  • On electrically suitable three/four-pin low-voltage ports, provide compact alternative 2.54 mm header/Molex-style and keyed STEMMA-family footprints. Populate one connector option per shared position and document its pin order. Use STEMMA QT only for compatible four-wire I²C; connector appearance does not make another signal protocol I²C-compatible.
  • Render each supported connector population separately. Document clearances, cable access and the exact fitted option.
  • Use uppercase titles in a consistent Montserrat-style face, labels on both sides, visible domain boundaries, a revision-specific wiring guide and this page’s URL on the silk where readable.
  • Keep mounting-hole centers on a documented 10 mm lattice; add cable-tie holes where space and electrical clearances permit. Place status LEDs near accessible edges and give every indicator its own disable solder jumper. Provide labeled test pads and a ground observation point.
  • Review applicable DC power entries for reverse-polarity cutoff with a blinking warning, overvoltage cutoff/indication, controlled startup and electronic overcurrent protection. Indicator and protection circuits must work in the fault state without defeating isolation or safe output defaults. Thermal protection belongs only where the power/thermal analysis justifies it.
  • Electronic protection does not automatically replace a required mains/branch safety fuse. Backfeed blocking and inductive-load flyback clamps are separate design functions. Do not add identity EEPROMs, fault memory, calibration storage or paid self-test hardware under this upgrade program.

Design sources

Documentation route: smoothieware.org/extensions/wireless-series-master.

Additive design studies

The 2026-10-11 upgrade program has saved additional candidates v11, v12, v13. These studies preserve the historical design described above. Their connector, LED, mechanical and protection changes are revision-specific and remain unqualified.

See the per-board changes, failures and remaining work and mandatory family specification. Use the source hash and native check for the exact candidate being reviewed; do not infer hardware ratings from a rendered population.

Upgrade candidate readback

The three additional revisions are v11, v12, v13. They are engineering studies; saved CAD and renders do not release the hardware. The latest candidate is described below. Older baseline notes above remain historical.

wireless-series-master

  • Latest PCB source, SHA-256 7e78f17eff86bef945feb82d979ce93fcdc8adc4aa58c7669be089c9d32f6438.
  • Last native check: 0 errors, including 0 open connections. This is a CAD result, not electrical, assembly or firmware qualification.
  • Alternative connector lands recorded: J3 / PinHeader_1x04_P2.54mm_Vertical. Fit only the selected population; check its pin map and voltage in the design record.
  • normal population/render record: 6 images; source current; image hashes match; 0 unresolved models.
  • stemma population/render record: 6 images; source current; image hashes match; 0 unresolved models.
  • Changes, failed trials and remaining work.

Applicable protection, current-path, thermal, pinout, cable access and physical tests remain open wherever the linked board record has not verified them. A zero native-error count does not close those gates.

Second-round annotation readback v14 — 2026-10-13

Protected source v13; current PCB SHA-256 3ebeab631adafcb91e2c705f9972ce772818bd22bb09b81b3740ca62f0af920c. Fresh native checks: zero enabled errors, opens, schematic mismatches and ERC findings; 3 PCB warnings remain. Electrical geometry/project rules unchanged; 68 historical files, 66 model entries,17 exports and12 current population images verified. All12 populated/bare views inspected. Full documentation URL is readable in the current renders. Physical qualification remains open; no price or area savings claimed.

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