Project Start Inquiry

flux

I established the layout workflow and constraints, but execution stopped before any PCB mutations because no ACUs are available.
Remaining
  • Verify/correct power-subsystem footprints.
  • Size the spacious prototype board and set its 4-layer stackup.
  • Apply high-current net rules.
  • Place the power components and run placement/DRC review.
After adding ACUs, repeat this request to resume.
merlin2232

merlin2232

Verify footprints, set board size and high-current rules, then place the power components for review.

flux

I’ll verify the power footprints, configure a spacious 4-layer board and high-current rules, then place the power chain and run a placement/DRC review.
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Referenced guidance.
1/4 Verify and correct power-subsystem footprints

Verify and correct power-subsystem footprints

Set spacious board size and 4-layer stackup

Apply high-current layout rules

Place power components and review DRC

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Project Specification
1. Purpose
Create a spacious, easy-to-assemble prototype carrier PCB for an ESP32-S3-DevKitC-1-N8R2. The board will provide removable GPS and 915 MHz LoRa modules, regulated power, onboard charging for a 3-cell LiPo battery, and access to every ESP32 header pin for testing.
2. Core Modules
  • Controller: ESP32-S3-DevKitC-1-N8R2, removable via 2.54 mm female header sockets.
  • GPS: Teyleten Robot ATGM336H breakout, removable via headers; final mechanical footprint and pin order must be verified against the purchased module.
  • LoRa: 915 MHz SX1262 module, 22 mm × 19 mm, 2.54 mm pin pitch, approximately 22 dBm maximum output, removable through two 1×8 socket rows after male pins are fitted to the module.
  • LoRa signals: 3V3, GND, SPI CS/CLK/MOSI/MISO, RESET, BUSY, DIO1, DIO2, RXEN, TXEN, and ANT connection as applicable.
3. Battery and Charging
  • Battery: 3S LiPo, 11.1 V nominal and 12.6 V fully charged.
  • Capacity: 2200 mAh.
  • Main connector: Deans/T-style connector.
  • Balance connector: Separate 4-pin 3S balance connector; exact connector family and pin order must be confirmed before layout.
  • Target charge current: 1 A nominal.
  • Inputs: USB-C Power Delivery and 15 V DC barrel input.
  • The board shall accept either charging input with protected source selection or power OR-ing.
  • Charging shall use a dedicated 3S Li-ion/LiPo charger architecture with cell supervision/balancing and appropriate input, battery, thermal, overcurrent, overvoltage, undervoltage, and reverse-current protection.
  • The system must remain operational while charging. Charger current sensing and charge termination must not be corrupted by system load; use a suitable power-path/load-sharing architecture.
4. Power Rails
  • 5 V rail: Regulated from the battery/input power path and sized for the ESP32-S3 DevKit and available prototype load margin.
  • 3.3 V rail: Dedicated regulated rail for the SX1262 module and GPS where required; do not rely solely on the DevKit regulator for all peripherals.
  • Provide local bulk capacitance and high-frequency decoupling near each removable module.
  • Include clearly labeled test points for battery voltage, charger input, 5 V, 3.3 V, and ground.
5. ESP32 Connectivity
  • Place the ESP32-S3-DevKitC-1-N8R2 on removable sockets.
  • Add a parallel row of unpopulated 2.54 mm plated through-holes beside every DevKit pin.
  • Label all breakout holes clearly on silkscreen.
  • Assign GPS UART and LoRa SPI/control signals to ESP32 GPIOs that do not interfere with boot strapping or normal USB/programming operation.
  • Preserve access to the DevKit USB connector, EN button, BOOT button, and antenna keepout.
6. RF and Placement Requirements
  • Place the ESP32 antenna end at a board edge with the manufacturer-recommended copper/component keepout.
  • Place the GPS module/antenna region away from switching regulators, inductors, USB-C circuitry, and the LoRa antenna feed.
  • Place the LoRa module near a board edge and keep its antenna connector/feed accessible.
  • Do not route noisy switching nodes beneath either RF module or antenna region.
7. Prototype and Mechanical Requirements
  • Prioritize assembly access, probing, readable labels, and module clearance over minimum PCB area.
  • Use generous spacing around headers and connectors.
  • Provide mounting holes near the board corners.
  • Clearly mark polarity, connector purpose, pin 1, battery cell order, and high-current paths.
  • Use a board stackup and copper weight suitable for the selected charging current and system current.
8. User Interface and Expansion
  • No additional buttons, display, buzzer, sensors, or prop-control interfaces are required in this revision.
  • The ESP32 breakout holes provide expansion for future concept testing.
9. Validation Criteria
  • Correct mechanical fit and orientation for all three removable modules.
  • Stable 5 V and 3.3 V rails across battery discharge and charging conditions.
  • Safe 3S charging to 12.6 V with verified cell monitoring/balancing behavior.
  • Device remains operational during charging without false charge termination.
  • No ESP32 boot failures caused by assigned peripheral GPIOs.
  • GPS UART communication and satellite acquisition verified.
  • LoRa SPI communication, BUSY/RESET/control operation, and 915 MHz packet transmission verified with a suitable antenna attached.
  • Thermal rise of charger, regulators, protection devices, connectors, and PCB copper remains within component ratings.
10. Open Decisions Before Schematic Freeze
  • Exact ATGM336H breakout dimensions, pin order, logic voltage, and header geometry.
  • Exact 4-pin balance connector family and cell-tap pin order.
  • USB-C PD sink/controller and supported source profiles.
  • 15 V barrel jack dimensions, polarity, and current rating.
  • Final charger, cell-balancing/protection, power-path, 5 V regulator, and 3.3 V regulator selection following a power budget.
  • Target maximum system current and desired reserve capacity on the breakout rails.
  • Final board dimensions and mounting-hole pattern.

  • 1. Purpose

  • 2. Core Modules

  • 3. Battery and Charging

  • 4. Power Rails

  • 5. ESP32 Connectivity

  • 6. RF and Placement Requirements

  • 7. Prototype and Mechanical Requirements

  • 8. User Interface and Expansion

  • 9. Validation Criteria

  • 10. Open Decisions Before Schematic Freeze

ESP32-S3 3S LiPo GPS LoRa Carrier

ESP32-S3 3S LiPo GPS LoRa Carrier thumbnail
Dual-input 15 V USB-C PD/barrel power system with BQ25792 NVDC charging, independent 3S LiPo protection/balancing, and regulated 5 V/3.3 V rails for an ESP32-S3 GPS/LoRa carrier.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$18.92–$242.97

Digi-Key

$1.02–$1.22

HQonline

$12.40–$12.57

LCSC

$32.81–$33.00

Mouser

$43.01–$55.53

TME

$1.38

Verical

$9.96–$121.03

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