Fixing ERC/DRC Errors and Routing


Replacement/placement completed, but validation found two remaining blocker types: stale traces from the old footprints and U7 still has duplicate exposed-pad footprint geometry. I’m correcting U7 with a different clean same-function BQ24074 package entry, then deleting stale traces before rechecking.
Pre-routing check is now clean, so I’m spending the routing ACUs now. I also removed the last stale trace first to avoid wasting a routing pass.
Blocked: the project ran out of ACUs during the auto-route job, so I can’t continue tool work in this run.
Completed so far:
  • Replaced the problematic footprint components:
    • U1 ESP32-S3 module
    • U3 MAX-M10S GNSS
    • U7 BQ24074 charger/power path
    • U8 TPS63070 buck-boost regulator
  • Restored their original functional connections: USB, GPS UART, I2C, I2S mic, battery charger, SYS/3V3 power, boot/reset.
  • Re-placed the replacements on the PCB.
  • Removed stale/dangling traces from the old footprints.
  • Fixed the SYS rail reconnection for C12/R15.
  • Reduced small-pin routing width for U8 BB_L1 and BB_VAUX.
  • Got the board to pass the pre-routing feasibility check before routing was attempted.
Remaining:
  • Add ACUs, then re-run routing.
  • The paused route reported USB differential pair routing stalled, so after ACUs are available the next step is to adjust/route USB_DP/USB_DN specifically, then run final ERC/DRC/airwire checks.
  • U3:VIO_SEL may still appear as a false ERC issue; per MAX-M10S datasheet it should be left open for 3.3 V V_IO operation.
Route USB first
Verify VIO_SEL
Run final checks
Inspect footprints

FCC / CE Integration Draft
Product and radio scope
Draft integration record for the smart pet collar containing ESP32-S3-WROOM-1-N8R2 (2.4 GHz Wi-Fi/BLE), native USB-C J1, and a MAX-M10S GNSS receiver with external antenna connector J3. GNSS is receive-only; the ESP32 module is the intentional radiator. This draft is not a declaration of conformity or grant authorization.
Integration controls
  • Preserve the ESP32-S3-WROOM-1 module antenna edge placement and all-layer antenna keepout from Espressif's current hardware integration guidance. No metal, battery, cable, enclosure coating, animal tag, or body-contact structure may enter the keepout without RF re-evaluation.
  • Record exact module MPN, module label/FCC ID/CE evidence, firmware radio configuration, antenna type/gain, enclosure materials, battery, PCB revision, and assembly site in the technical file.
  • Use only antenna configurations permitted by the module approval. This design uses the WROOM-1 PCB antenna; J3 is for GNSS and must not be represented as a Wi-Fi/BLE antenna connector.
  • Keep USB, switching regulator, I2S and GNSS RF routing/configuration fixed after compliance testing. Any module, antenna, enclosure, clock, power, or firmware RF change triggers impact review.
  • Production firmware shall enforce legal channel/power/domain settings, disable unauthorized test modes, protect identity/keys, and provide a traceable version/hash.
United States draft checklist
  • Confirm the exact installed module's current FCC modular grant and all grant conditions before labeling or sale.
  • Apply host-product labeling such as “Contains FCC ID: …” only after verifying the actual module FCC ID and required wording.
  • Include required Part 15 user statements and RF exposure instructions in the final manual.
  • Evaluate portable/body-worn use and separation distance. A pet collar is used in direct proximity to an animal and may also be handled/worn near people; do not assume the module's generic separation conditions apply.
  • Perform host-product FCC Part 15B unintentional-radiator testing. Perform additional intentional-radiator/RF exposure/SAR or MPE testing when required by the module grant, antenna/enclosure/use configuration, simultaneous transmission, or accredited-lab assessment.
European Union draft checklist
  • Build the RED 2014/53/EU technical documentation: product description, schematics/layout/BOM, risk assessment, module evidence, antenna information, firmware version, test reports, labels, instructions, and EU Declaration of Conformity.
  • Accredited-lab scope to confirm applicable harmonized standards at the test date; likely areas include radio spectrum (2.4 GHz), EMC, electrical safety/health and RF exposure. Do not freeze standard numbers from this draft without regulatory review.
  • Review RoHS, REACH/SCIP where applicable, WEEE marking/producer obligations, battery regulation/transport labeling, and country-specific recycling/registration.
  • Ensure user information covers frequency bands, maximum RF power, charging, battery disposal, environmental limits, and restrictions.
Mandatory external and post-assembly activities
  • External accredited lab: final-enclosure radiated emissions/immunity, radio performance, RF exposure assessment, ESD, and any required SAR/MPE; USB-cable and charging configurations included.
  • Mechanical/animal-contact validation: antenna detuning on representative animal/body phantoms, wet fur/sweat/saliva exposure, strap/buckle orientation, enclosure wear, bite/impact, cleaning agents, ingress, and temperature at all skin-contact surfaces.
  • Post-assembly firmware flashing: flash only released firmware; verify secure identity/configuration, radio regulatory settings and firmware hash; lock or control manufacturing test modes.
  • Production conformity: retain serial/lot traceability, module label records, approved component substitutions, calibration/test logs and change-control review.
Open items / no-claim boundary
The exact ESP32 module FCC ID, final antenna gain evidence, final enclosure, intended human separation, target markets, applicable standards editions, battery model, and lab test plan remain open. No FCC/CE mark, “certified” claim, or production release is authorized by this draft. Regulatory counsel/test lab must approve the final integration and labeling.
  • Product and radio scope

  • Integration controls

  • United States draft checklist

  • European Union draft checklist

  • Mandatory external and post-assembly activities

  • Open items / no-claim boundary