Ultra Small Ethernet + RP2040 Board Production Record

Summary

I have done a lot of projects related to RP2040. We always used the Pico board to proceed. I used a lot of W5100S-EVB-Pico, an Ethernet-enabled board in Pico. Now, I want to make a smaller and more efficient board than this board and proceed with the project.

XIAO-Series

The XIAO board is the smallest configuration based on various MCUs. It's made very small like the image.

WIZnet W5100S

W5100S is a TCP/IP Ethernet chip.The W5100S helps the MCU communicate easily via SPI.

Schematics design start

The circuit was designed simply. I just added two headers to fit the XIAORP2040 board into the W5100S Chip circuit. It was important to note that we had to match the pinmap and the porting of the nRST.

The biggest advantage of the XIAO-RP2040 board is that it is compact, so the W5100S-XIAO board was also made compact. As a result, the length and impedance matching of the differential pair line had no choice but to give up.(But I got it right to some extent. As much as I can)

I was disappointed because it looked bigger than I thought when I saw the completion of 3D... Next time, we should consider replacing the RJ-45 with the SMD type and placing the W5100S on the bottom surface. First of all, I decided to proceed like this..

PCB ordering

After finishing the work, I placed an order at Seeed Fusion PCB/PCBA Services.

I could finish ordering the board very easily. It seems that Seed Studio takes care of minor problems when ordering. I was able to do it comfortably.

PCB assembly

Three days later... The PCB arrived well. I made a PCB in black to fit the XIAO RP2040 board, and I think it came out nicely.

I wanted to make it work, so I finished assembling it quickly. When I put it together, I felt it was much smaller than I thought. (I didn't take the picture well even when I saw it.)

It fits perfectly when fitted. I like it because it's very compact. The Ethernet test is done with Loopback, and it works well.

Next

Next time, I will proceed with an interesting project through this board and post it.