---
title: "Raspberry Pi + Wiznet Ethernet (W5100S/W5500/W6100) – Hardware + Firmware Notes"
url: "https://maker.wiznet.io/forum/15732"
markdown_url: "https://maker.wiznet.io/forum/15732/md"
type: "Forum topic"
category: "MCU & Boards"
author: "sanjaay22"
created: "2025-05-19T16:04:27+09:00"
last_activity: "2025-05-20T15:05:08+09:00"
language: "en"
tags: ["Raspberry Pi"]
views: 7
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Raspberry Pi + Wiznet Ethernet (W5100S/W5500/W6100) – Hardware + Firmware Notes

## Question

Asked by sanjaay22 on 2025-05-19 in MCU & Boards.

Hi all,

I've been experimenting with combining Raspberry Pi Pico W and Wiznet Ethernet HATs (W5100S / W5500 / W6100), and wanted to share a few observations + ask for guidance:

I tried running the basic WIZnet MicroPython example from the GitHub repo:

```plaintext
from machine import Pin, SPI
import network
import time

time.sleep(5)
led = Pin(25, Pin.OUT)

def w5x00_init():
    spi = SPI(0, 10_000_000, mosi=Pin(19), miso=Pin(16), sck=Pin(18))
    nic = network.WIZNET5K(spi, Pin(17), Pin(20))  # CS, Reset
    nic.active(True)
```

I'm also trying to get UDP comms working with the W5500-EVB-PICO2 and W6100, using the new Earle Philhower RP2040 Arduino core.

Problems:

- Ethernet.h works with the old Wiznet core, but not in Earle's core.

- The UDP examples use WiFi libraries (?) – very confusing for Ethernet-based devices.

- Changing the Arduino core’s Ethernet stack config (IPv6+IPv4, etc.) seems to break things even more when used with W6100.

Has anyone successfully done UDP over IPv6 with W6100 + RP2040 in Arduino? Or are we still tied to older Wiznet forks?

One quick sidenote for those building hardware stacks with Raspberry Pi boards – I found this brand page really helpful to get official and up-to-date stock in India:

<https://robocraze.com/pages/robocraze-authorized-reseller-raspberry-pi-india>

I got my Raspberry Pi Pico W and a couple of W5x00 HATs from there. Having trusted hardware really saves debugging time when you're already fighting firmware issues

Looking forward to hearing your suggestions, especially if anyone's been down this exact RP2040 + Wiznet + UDP rabbit hole.

Thanks in advance!

## Replies

### Reply 1 by Hannah, 2025-05-20

Are you currently using the W5500-EVB-Pico2 and W6100-EVB-Pico boards to run the UDP code? Or are you using a Pico W with a WIZnet Ethernet HAT instead?

Problems:

- Ethernet.h works with the old Wiznet core, but not in Earle's core.

- The UDP examples use WiFi libraries (?) – very confusing for Ethernet-based devices.

-> I tested the UDPSendReceiveString example with the W5500-EVB-Pico2 board using Earle's core, and Ethernet.h worked properly. Also, the example does not include any WiFi libraries. Could you let me know exactly which example you used?

- Changing the Arduino core’s Ethernet stack config (IPv6+IPv4, etc.) seems to break things even more when used with W6100.

-> Recently, Earle's core does not support the W6100. The W6100 works with the WIZnet core. Here's a guide link for reference:

<https://www.hackster.io/loveivyou/ipv4-ipv6-w6100-evb-pico-with-arduino-ide-6bb7df>

---

Source: https://maker.wiznet.io/forum/15732