PCB Design for Dual-Motor Control System

flux

0:12

Thought for a moment

I’ll proceed into DRC cleanup: first I’ll inspect the current layout/stackup and DRC categories, then size/configure the board if needed, place components by functional block, and address layout DRC before routing.

flux

0:27

Thought for 7 sec

1/5 Inspect current PCB layout size, stackup, placement state, and DRC categories

Thought for a moment

I started the DRC/layout phase and confirmed the main issue is PCB airwires: the schematic ERC is clean, but the board has not yet been placed/routed, so full DRC reports many unrouted nets.
Completed this session:
  • Acknowledged the transition into DRC/layout cleanup.
  • Loaded the DRC, layout setup, placement, and routing procedures.
  • Created the layout-phase todo plan.
  • Re-ran full review and confirmed the dominant DRC category is airwires.
  • Verified critical nets still exist for STM32H7, ADS1256, ADS1220, HX711, REF5025, and TPS7A4700.
  • Confirmed the earlier ERC-only cleanup remains valid.
Remaining work:
  • Inspect current board size, stackup, and component placement state.
  • Set a suitable compact 4-layer or 6-layer stackup and board size.
  • Add layout rules for USB/CAN impedance, power widths, analog separation, and high-current VIN/shunt paths.
  • Place components by functional block: power/CAN/motor side, STM32/memory center, ADC/load-cell analog isolated area, ESP32 antenna at edge, connectors at edges.
  • Run post-placement DRC and fix non-routing violations.
  • Pause for your approval of placement before routing traces.
Use 4-layer setup
Use 6-layer setup
Inspect DRC blockers
Functional auto-placement
Fix non-routing issues
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Project Specification: Dual-Motor Tape Tension Controller
Purpose
Compact professional-grade rigid PCB for a dual-motor tape tension control system using an STM32F407VET6 real-time controller, precision load-cell acquisition, CAN links to two Maxon EPOS4 Compact 50/5 drives, wireless coprocessor, external memory, USB-C, and robust 12-24 V power input protection.
Functional Blocks
  1. Power input and protection: 12-24 V DC input, reverse/transient protection, bulk capacitance, 5 V buck, digital 3.3 V rail, low-noise analog rails, star-point AGND/DGND strategy.
  2. MCU core: STM32F407VET6 LQFP-100, SWD/JTAG header, USB-C FS device port, BOOT/NRST support, HSE/LSE clocking, decoupling, VCAP capacitors, GPIO breakout.
  3. Memory: QSPI NOR flash, FSMC external SRAM, MicroSD over SDIO, I2C EEPROM.
  4. Wireless: ESP32-C3/S3 module as WiFi/BLE coprocessor over SPI/UART with EN/BOOT/reset support and antenna keepout.
  5. Analog front end: ADS1256 + REF5025, ADS1220, HX711, load-cell connectors, EMI filtering, LC-filtered analog rails, shield-can footprints/provisions.
  6. CAN/motor interface: two protected CAN transceivers, selectable 120 ohm terminations, CAN TVS, EPOS4 connectorization.
  7. Regenerative braking protection: comparator-monitored DC bus shunt chopper with rugged MOSFET, high-wattage dump resistor connector/footprint, supply blocking diode/protection.
  8. UI/audio/expansion: buzzer transistor driver, I2S audio DAC/amplifier and speaker connector, LEDs, WS2812B, SPI/I2C/I2S headers.
Key Layout Rules
  • Use 6-layer stackup for mixed-signal + USB/CAN impedance + multiple power rails.
  • Maintain continuous ground reference planes; implement analog/digital separation by controlled partitioning and single-point stitching, not by breaking high-speed return paths.
  • Keep ADC/load-cell analog section far from switching power, CAN, ESP32 antenna, and high-speed digital buses.
  • Route USB D+/D- as 90 ohm differential pair and CANH/CANL as 120 ohm differential pair.
  • Place decoupling capacitors at IC power pins; place analog reference and ADC input filters inside shielded analog region.
Assumptions Pending Datasheet/BOM Finalization
  • Main supply input is externally current-limited 12-24 V DC.
  • Motors are driven by external EPOS4 Compact 50/5 modules; this PCB handles control, comms, sensing, and bus protection/chopper control, not phase power switching.
  • Load-cell excitation and connector pinouts will be designed for 4-wire load cells unless user specifies 6-wire sense connections.

    Purpose

    Functional Blocks

    Key Layout Rules

    Assumptions Pending Datasheet/BOM Finalization

Documents

    Project Specification: Dual-Motor Tape Tension Controller

    Power Budget and Architecture

    STM32H7 Migration Status

    ERC Wiring Status

Assets

Assets are files uploaded to this project which can be used in various ways.

Dual-Motor Tape Tension Controller thumbnail
Professional-grade STM32F407 dual-motor tape tension controller with precision load-cell ADCs, CAN interfaces, ESP32 wireless coprocessor, USB-C, external memory, and protected 12–24 V power architecture.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$64.23–$69.29

Digi-Key

$88.31–$93.38

HQonline

$26.17–$26.34

LCSC

$112.90–$125.72

Mouser

$115.19

TME

$18.56

Verical

$60.84–$92.08

Controls