Ground Plane Setup Instructions

flux

I moved the USB/CH340 section to improve routing and reran autoroute.
What changed:
  • Repositioned J1/J2 with U3/U4 and local USB passives for cleaner USB D+/D− escape.
  • Removed stale USB-area traces/vias before routing.
  • Reran autoroute from the updated placement.
  • Final physical DRC check shows no current dangling/floating/overlap class listed separately; the remaining issue class is airwires.
Remaining:
  • 74 airwires still remain.
  • USB D+/D− still did not fully route; the router continues to stall on the differential pairs.
  • Manufacturing MPN errors are still ignored per your instruction.
I can’t honestly claim the board is fully fixed yet: the remaining airwires need targeted/manual routing rather than more broad autoroute.
evanrowlands

evanrowlands

your usless im cancelling

flux

I understand. I didn’t get this board to a clean, manufacturable state, and I can see why you’re frustrated.
If you do cancel, before leaving I strongly recommend:
  • Use version history to restore the last known good revision before these routing/layout attempts.
  • Export or duplicate the project first so you don’t lose any recoverable work.
  • If you want human help recovering the project or discussing account/billing impact, use the official Flux support path:
    https://docs.flux.ai/Introduction/getting-support
I’m sorry for the wasted time and cost.
Restore last good
Find remaining airwires
Explain USB fix
Create recovery plan
Export current design
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J2
J4
J1
J3
Project Specification — SMC3 3DOF Motion Controller
Goal
Design a professional PCB that replaces the loose wiring used in existing EMR motion simulator builds. The board will contain two independent Arduino Uno-compatible ATmega328P controller sections, each with its own USB-C serial interface, so SimTools can see two separate controller interfaces.
Confirmed Architecture
  • Interface 1: USB-C 1 + USB-UART 1 + ATmega328P MCU 1.
    • Runs the uploaded SMC3 packet serial soft-start sketch.
    • Controls the Sabertooth 2x60 for the two front motors.
    • Uses two Hall/pot feedback inputs.
  • Interface 2: USB-C 2 + USB-UART 2 + ATmega328P MCU 2.
    • Runs the same SMC3 sketch with only one motor channel used.
    • Controls the SyRen 50 for the traction-loss motor.
    • Uses one Hall/pot feedback input.
  • Power source: external 12 V, 600 W, 60 A PSU.
  • Motor drivers: external Dimension Engineering Sabertooth 2x60 and SyRen 50 modules; the PCB provides power distribution, fused outputs, logic/serial/control wiring, feedback inputs, and E-stop integration.
  • Feedback sensors: three Hall/pot style 3-wire sensors, treated as 5 V, GND, signal into ADC inputs unless later confirmed otherwise.
Uploaded Firmware Findings
The sketch is configured for MODE3, using Sabertooth packet/simple serial style control through SoftwareSerial:
  • Hardware USB serial: pins D0/D1 via USB-UART.
  • Motor driver serial: SoftwareSerial on D12/D13, with D12 = RX and D13 = TX in the sketch.
  • Feedback inputs: A0, A1, A2.
  • Optional motion scaler: A5, disabled unless firmware option is enabled.
  • Standard SMC3 pin list still exists in comments for H-bridge modes, but the active uploaded configuration is MODE3 for Sabertooth/SyRen style serial driver control.
Functional Blocks
  1. 12 V Power Distribution and Safety
    • 12 V PSU input connector.
    • Main E-stop relay/contactor path.
    • Separate fused outputs for Sabertooth 2x60 and SyRen 50 feeds.
    • Logic buck regulator from 12 V to 5 V.
    • Bulk capacitance and reverse/transient protection as appropriate.
  2. MCU 1 — Front Motor Interface
    • ATmega328P at 16 MHz, 5 V logic.
    • USB-C 1 to USB-UART bridge.
    • ICSP header and reset button.
    • SoftwareSerial TX to Sabertooth/SyRen-compatible serial output connector.
    • Feedback connectors for Motor 1 and Motor 2.
  3. MCU 2 — Traction Loss Interface
    • ATmega328P at 16 MHz, 5 V logic.
    • USB-C 2 to USB-UART bridge.
    • ICSP header and reset button.
    • SoftwareSerial TX to SyRen 50 serial output connector.
    • Feedback connector for traction-loss motor.
  4. Driver Interface Connectors
    • Sabertooth 2x60 logic connector for ground and serial/control input.
    • SyRen 50 logic connector for ground and serial/control input.
    • External motor-power driver wiring kept high current and safety-rated.
  5. Sensor / Pot Connectors
    • POT/Hall 1: 5 V, signal to MCU 1 A0, GND.
    • POT/Hall 2: 5 V, signal to MCU 1 A1, GND.
    • POT/Hall 3: 5 V, signal to MCU 2 A0, GND.
    • Optional RC filtering and input protection on each ADC input.
  6. Indicators and Service
    • Power LED.
    • TX/activity LEDs for each USB-UART/MCU interface.
    • Fault/E-stop indicator.
    • ICSP headers for both ATmega328P chips.
Important Design Constraints
  • The board should be professional and clear, minimizing off-board wiring compared with individual Uno boards.
  • High-current 12 V motor power must be physically separated from USB/logic signals.
  • 60 A-class current is not suitable for thin PCB traces. The board should either use heavy copper/busbar/high-current terminals or route motor power externally through rated fuses/relay/driver terminals.
  • E-stop must interrupt motor power or driver enable in hardware; firmware-only E-stop is not sufficient.
  • USB-C ports are USB 2.0 device ports, not USB Power Delivery inputs.
Open Items Before Final PCB Layout
  • Exact connector series and wire gauge target for 12 V/motor wiring.
  • Whether high-current 12 V distribution will be carried on the PCB copper or handled by external wiring/busbars mounted to the board.
  • Exact Hall sensor model/output type if different from 0–5 V analog.
  • Desired board size and enclosure/mounting hole constraints.

  • Goal

  • Confirmed Architecture

  • Uploaded Firmware Findings

  • Functional Blocks

  • Important Design Constraints

  • Open Items Before Final PCB Layout