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A user on Reddit's r/PrintedCircuitBoard subreddit shared their experience and sought advice regarding a custom PCB design integrating an ESP32 microcontroller and a W5500 Ethernet controller. The design aimed to include Power over Ethernet (PoE), which was unsuccessful and is to be discussed separately.

Key Issues and Discussion Points

IP Address Issue:

• The main problem highlighted was that the PCB outputs an IP address of 0.0.0.0 when interfaced with the ESP32, indicating that the device failed to obtain an IP address automatically (via DHCP) and did not revert to a static IP correctly.

PHY Traces and Impedance:

• The user mentioned they had designed the PHY traces as differential pairs but was concerned they might not have achieved the required 100 ohm differential impedance necessary for optimal signal integrity.

Comparison with W5500 Lite:

• They noted that the code used was previously successful with a W5500 Lite module, suggesting the issues might be specific to the physical layout or connection integrity in the new PCB design.

Recommendations from the Community

Trace and Impedance Verification:

• Community responses emphasized checking the impedance of the differential pairs, as incorrect impedance can lead to significant signal integrity issues affecting data transmission.

PCB and Schematic Review:

• It was recommended to thoroughly review the PCB design and schematic, particularly the connections between the ESP32 and the W5500, to ensure all SPI and Ethernet-related connections are accurately implemented.

Use of Tools and Diagnostics:

• Suggestions included using tools such as oscilloscopes to observe the signals on the SPI bus actively and employing network troubleshooting tools to analyze the Ethernet signals.

Reevaluation of Component Placement and Routing:

• Advice was also given on possibly reevaluating the layout for noise sensitivity and signal path integrity, especially since high-speed signals are involved.

Firmware and Software Settings:

• Checking the firmware settings for initializing the W5500 was also advised, to ensure that the code correctly sets up the device for network communication.

Conclusion

The community feedback highlighted a comprehensive approach involving both hardware verification and firmware reevaluation to address the non-functional Ethernet communication in the custom PCB. The importance of correct trace impedance, accurate schematic implementation, and proper software settings were reiterated as critical factors for resolving the issues experienced.

This summary captures the essence of the community's advice and the user's situation as they work towards resolving the Ethernet communication problems on their custom PCB integrating an ESP32 and W5500 Ethernet controller.