---
title: "w5100s loopback OSError"
url: "https://maker.wiznet.io/forum/14690"
markdown_url: "https://maker.wiznet.io/forum/14690/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "mohit optimus"
created: "2022-10-21T07:05:29+09:00"
last_activity: "2022-10-21T07:05:29+09:00"
language: "en"
views: 374
replies: 0
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# w5100s loopback OSError

## Question

Asked by mohit optimus on 2022-10-21 in Ethernet Chips.

Hi,
I tried to run raspberry pi pico with Wiznet 5100s . I installed step by step the library and when i run loopback example from github it shows OSError : 4 and this OSError : changed every time i run the code.

Can anyone share me the connection of pi pico to wiznet w5100s and the ethernet cable connection.

is there any solution ??

---

Source: https://maker.wiznet.io/forum/14690