ESP32 Custom PCB Experiences: Grounding, RF Layout, and Long-Term Reliability

[jovelyngentallan02-blip]

Hi everyone,

I'm designing a custom ESP32-based board for a monitoring and control application and would appreciate feedback from people who have taken ESP32 designs from prototype to production.

The board includes:

• ESP32-WROOM module
• Multiple I2C and UART sensors
• RS-485 communication interface
• Relay and MOSFET-controlled outputs
• External 12V power input
• 4-layer PCB design

Current stackup:

• Layer 1: Components and signal routing
• Layer 2: Solid ground plane
• Layer 3: Power distribution and secondary routing
• Layer 4: Signals and low-speed routing

Most ESP32 discussions focus on firmware, but I'm particularly interested in PCB-related issues that may not become apparent until after manufacturing or field deployment.

Some questions:

1. What PCB layout mistakes have caused the most trouble in your ESP32 projects?
2. How much clearance do you typically leave around the ESP32 antenna region?
3. Have you experienced Wi-Fi or Bluetooth performance issues that were ultimately traced back to PCB layout?
4. Do you prefer a single continuous ground plane, or do you isolate noisy power sections from RF and sensor areas?
5. What power integrity or decoupling issues have you discovered only after building the first revision?
6. Have connector placement, grounding, or EMI issues caused unexpected reliability problems in deployed systems?

I'm also reviewing PCB design resources before finalizing the layout. Studied ESP32 RF layout, grounding strategies, and multilayer PCB design raised some interesting points about antenna keep-out areas and return-current paths. For those with production experience, do those recommendations generally align with what has worked well in practice?

I'd appreciate any lessons learned, especially issues that weren't obvious during schematic design but became apparent after PCB fabrication and testing.

Thanks!