STM32G431 Custom ROV Sensor PCB Review Before Manufacturing (Leak Detection + ESC Control + Jetson Interface)

[pln]

Hi everyone,

I’m designing my first custom PCB for an underwater ROV project and I would really appreciate feedback before moving closer to manufacturing.

A few months ago I shared the schematic review here, and after applying suggestions I completed the PCB routing stage.
Now I would like to ask for a review of the PCB layout itself, especially regarding signal integrity, grounding, routing quality, and overall reliability.

The board is designed around an STM32G431CB and acts as a sensor/control board communicating with a Jetson Orin Nano and a separate Power Distribution Board (PDB).

Main Functions

• Reading 4 leak sensors
• Generating ESC PWM outputs
• Communicating with Jetson Orin Nano
• Processing leak sensor states and sending a digital LEAK_FAULT signal to the PDB
• Interfacing with:
  • BNO08X IMU
  • D300 depth sensor
  • ESCs
  • Leak sensors

Board Layout Overview

• Bottom side:
  • 4 leak sensor connectors
• Left and right sides:
  • ESC connectors
• Top side:
  • Sensor and Jetson-related connectors
• Center:
  • STM32G431CB MCU

PCB Details

• 2-layer PCB
• Signal traces:
  • 0.25–0.30 mm
• Power traces:
  • 0.50 mm
• Mixed routing on top and bottom layers
• Ground planes added on both layers
• Most ESC lines are PWM signal lines only (power distribution is handled externally by the PDB)

Additional Design Notes

• Leak sensors are analog inputs to the STM32
• After processing leak sensor data, the MCU outputs a digital LEAK_FAULT signal to the PDB for emergency handling
• Jetson ↔ STM32 communication uses UART
• IMU communication uses I2C
• Board will operate inside an underwater enclosure

Questions / Feedback Requested

I would really appreciate opinions on:

1. General PCB routing quality for a first design
2. Grounding strategy and ground plane usage
3. Whether the trace widths seem reasonable
4. MCU decoupling capacitor placement
5. Any risky routing around the STM32 pins
6. Potential noise/interference issues from ESC signal lines
7. Whether the connector placement/layout looks practical
8. Any manufacturing or reliability concerns before ordering

I am especially worried about:

• Return current paths
• Noise coupling into sensor lines
• Whether the 2-layer approach is sufficient
• If the ground pours are implemented correctly

I’ve attached screenshots of both the routed PCB and the 3D view.

Thanks in advance — I’m still learning PCB design, so any criticism or recommendation is very valuable for me.