Project Getting Started

Received notification from "Smart Coaster PCB Fix" that it stopped — taking it from here.
Thought for 5 mins 52 sec
Thought for 8 sec — Troubleshooting executor issues
Referenced guidance.
Reading PCB Placement Corrections's report…
Thought for 11 sec
Created a thread
Remaining Placement Corrections
Starting...
View Thread
Thought for 8 sec
Awaiting 1 background task
Received notification from "PCB Placement Corrections" that it finished — picking the work back up.

flux

I preserved your manually adjusted J4 and LED placement and stopped the earlier correction passes that could overwrite them. A replacement pass was dispatched to handle only the remaining U1 support, C4/U5, USB support, buck-stage, pump-stage, and antenna-keepout work.
I could not inspect or reconcile that executor’s completed changes, so their exact state is unverified. Before routing, the live board still needs a read-only check confirming:
  • J4 and all LEDs remained unchanged.
  • U1, C1, and R2 clear the center-hole and antenna regions.
  • C4 is properly oriented beside U5.
  • U6/R9/R10/U7 are suitably arranged behind J4.
  • U3/L1/C18–C22/R11/R12 and Q1/D2/R7/R8 are compact and clear.
  • The antenna copper keepout exists across all copper layers.
  • No new overlaps, bounds errors, or center-hole violations were introduced.
Execution stopped because your ACUs ran out.
Check placement status
Review DRC issues
Verify antenna keepout
Document placement constraints

Waiting for input

Sign up to send

Files

Schematic

Layout

3D View

Project Specification
Project Overview
Single smart-bar bottle-position CAN node. Status: schematic draft. The board measures load-cell force, drives a 12 V brushed pump, and presents a controlled 24-pixel RGBWW light ring.
Intended Use
One node is connected as a short CAN stub to a regulated 12 V bar network. This is a production-intent SMD assembly; all functional components will be top-side during later layout.
What the Device Should Do
  • Measure a 4-wire bridge load cell through a NAU7802 I2C ADC.
  • Communicate on one 500 kbit/s classic-CAN stub; no pass-through and no local bus termination.
  • Provide native USB-C data/programming and optional USB 5 V service power.
  • Drive 24 SK6812RGBW-WS (2700–3000 K) LEDs with firmware-limited LED current.
  • Switch a 12 V, 0.5–0.7 A brushed pump (2 A inrush) with a protected low-side MOSFET.
System Architecture
Text
12V/CAN connector -> fuse + TVS -> 12-to-5 buck -> 5-to-3V3 buck -> ESP32-C3
                          |                 |                 |-> CAN + NAU7802
                          |                 |-> LED buffer -> 24 LEDs
                          |-> pump terminal + flyback + NMOS
USB-C -> ESD -> ESP32 native USB; USB 5V -> reverse-blocking ideal-diode option -> 5V rail
Load-cell connector -> NAU7802 -> I2C -> ESP32
Hardware Subsystems
  • Compute: Espressif ESP32-C3-MINI-1-H4X, 3.3 V.
  • CAN: TI TCAN334GDR, 3.3 V, normal mode tied active; CANH/CANL only to J1.
  • Load cell: specified Nuvoton NAU7802KGI with E+/E-/S+/S- connector. The library part is unavailable; its exact symbol/footprint remains a blocker.
  • LEDs: 24 SK6812RGBW-WS, 5 V, daisy chain; AHCT level buffer and 330 ohm first-pixel series resistor.
  • Pump: low-side N-MOSFET, 100 ohm gate resistor, 100 kΩ gate pull-down, SS56 flyback diode.
  • Power: protected 12 V input, TPS54302 5 V / 3 A buck, LMR33630 3.3 V synchronous buck.
Interfaces and Connections
  • J1: 12V, GND, CANH, CANL; 4-position 3.50 mm terminal block.
  • J2: E+, E-, S+, S- load-cell input.
  • J3: 12V_SW, GND pump output.
  • USB-C: USB 2.0 D+/D-, CC sink resistors, VBUS protection/OR option.
  • Factory pogo pads: 5V, GND, USB_D+, USB_D-, EN, GPIO9_BOOT.
Power Tree and Budget
See the separate Power Budget project file. LED firmware shall limit the 5 V LED load to <=0.5 A; hardware is nevertheless sized for the stated 1.9 A full-white LED worst case plus margin.
Physical Design Expectations
  • Later PCB layout: circular, 80 mm target OD and <=90 mm maximum.
  • Single-sided assembly, functional parts top-side, LEDs upward.
  • Provisionally reserve a rounded-rectangle 44 x 20 mm central opening and adjacent low-profile/component-free corridor for an 80 x 12.7 x 12.7 mm TAL220-class load-cell bar. Keep all connectors out of that corridor.
  • Future layout must report tallest component under the bar path so enclosure CAD can set boss height; no height limit is assumed now.
  • Later place 24 LEDs on 60 mm diameter centerline.
  • Later edge-mount ESP antenna with no copper/plane beneath antenna.
  • Reserve 3–4 enclosure standoff mounting holes for later placement.
Important Design Decisions
  • GPIO19/GPIO18 are fixed native USB D+/D−.
  • GPIO9 is reserved for BOOT with pull-up and button to GND. GPIO2 is pulled up only; GPIO8 is left unburdened. No peripheral uses GPIO9.
  • Proposed GPIO allocation: GPIO4 CAN_TX, GPIO5 CAN_RX, GPIO6 I2C_SDA, GPIO7 I2C_SCL, GPIO10 LED_DATA, GPIO3 PUMP_GATE, GPIO1 BUTTON_IN. ESP32 GPIO matrix permits TWAI and I2C assignment, subject to firmware configuration.
  • USB 5 V is limited by its source advertisement; it must not be relied on for the 1.9 A LED full-white condition.
Assumptions and Open Risks
  • 12 V input is regulated and remains below 14 V in normal operation; SMBJ14A is selected provisionally with a ~23.2 V clamp. All 12 V power-path parts require voltage rating above this clamp.
  • The selected 2 A-hold PTC must be thermally derated during final BOM review; it does not protect the pump branch selectively.
  • NAU7802KGI is missing from Flux library; no unverified substitute is allowed. This blocks a complete manufacturable load-cell schematic.
  • USB VBUS ideal-diode option is 1.5 A rated and therefore is service/low-load only; it is not a 2 A LED supply path.
Change Notes
  • Initial requirements captured; project renamed Smart Coaster CAN Node.

  • Project Overview

  • Intended Use

  • What the Device Should Do

  • System Architecture

  • Hardware Subsystems

  • Interfaces and Connections

  • Power Tree and Budget

  • Physical Design Expectations

  • Important Design Decisions

  • Assumptions and Open Risks

  • Change Notes