General • Re: Pico Dual Ethernet

In the case of a picoW with a dual Ethernet hat, would you reccomend 2 of the Wiznet hats you showed above?

I would, have effectively chosen that path. There are potential alternatives but I haven't investigated those to any great extent. Any interface board with RJ45 and SPI should be usable. The options I am aware of are -

• WIZnet W5100S HAT
• MicroChip ENC28J60
• Microchip LAN8720
• SB Components NetPi
• CH9120

The advantage I see of the WIZnet HAT is that MicroPython supports it which means there is a ready to use reference design for it. Plus there's the full EVB board which means code can be tested, which, if it works, should also work for a Pico with the HAT. That helps distinguish wiring errors from code errors. AIUI it's also supported by Arduino IDE.

The ENC28J60 is well established but long in the tooth. It is little more than an ethernet frame receiver and transmitter but that can make it ideal if you can live within its limitations. If my focus wasn't on MicroPython this would probably be my choice. I believe there is a library for using it with Arduino IDE.

The LAN8720 is more low-level, an RMII PHY device, requires more interfacing, and the software appears to me to be more complicated.

I don't know much about the NetPi, what chip that uses, and it seems a little expensive but does include a 240x240 display and mini-joystick which could be useful.

No idea about the CH9120. That seems to support its own internal TCP/IP stack offering a UART interface. That might be useful if it has a raw mode ala ENC28J60 using UART instead of SPI.

There are also various bit-banged implementations out there. But I see those for 'because I can' projects rather than the starting point for anything wanting to use ethernet.

Statistics: Posted by hippy — Sat Mar 23, 2024 11:57 am

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