---
title: "How one Raspberry Pi user solved W5500 SPI Configuration issues (Raspberry Pi 4)"
url: "https://maker.wiznet.io/jakelee/projects/how-one-raspberry-pi-user-solved-w5500-spi-configuration-issues-raspberry-pi-4-/"
markdown_url: "https://maker.wiznet.io/jakelee/projects/how-one-raspberry-pi-user-solved-w5500-spi-configuration-issues-raspberry-pi-4-/md"
type: "UCC: User Created Content"
author: "Nathol"
author_url: "https://forums.raspberrypi.com/viewtopic.php?t=366992"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "Nathol"
original_url: "https://forums.raspberrypi.com/viewtopic.php?t=366992"
published: "2025-11-20"
language: "en"
likes: 0
views: 641
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# How one Raspberry Pi user solved W5500 SPI Configuration issues (Raspberry Pi 4)

> A Raspberry Pi 4 user attempted to configure W5500 Ethernet module over SPI but ran into multiple issues.

Original author: Nathol (source: https://forums.raspberrypi.com/viewtopic.php?t=366992)

## Article

### **🔎 Overview**

A Raspberry Pi 4 user attempted to configure a W5500 Ethernet module over SPI but ran into multiple issues:

The W5500 wasn’t visible on the SPI bus

`dtoverlay` wiring didn’t behave as expected

Incorrect chip-select assignments caused the driver to fail

After several attempts and community input, the user posted a **self-solution**, which turned out to be extremely helpful for others hitting similar problems.

This is a great example of how subtle configuration details can block W5500 operation — especially on Linux targets like Raspberry Pi.

---

### **💬 What the Community Encountered**

The user initially enabled **SPI0** but used pin assignments that belonged to **SPI1** on the Raspberry Pi 4.

They attempted `dtoverlay=spi1-3cs`, but their W5500 driver was still reading garbage values.

They realized the **chip-select pin was never being driven**, so the W5500 never responded.

After examining their wiring and overlays, they discovered that their chosen CS pin was **not compatible** with the overlay they selected.

Once the proper combination of:
**SPI bus → CS pin → Overlay → Wiring**
was aligned, the W5500 responded correctly.

---

### **🛠️ The Final Fix (as described by the user)**

Their working setup was:

**Bus:** `SPI1`

**Overlay:** `dtoverlay=spi1-1cs`

**Pins:**

SCK → GPIO 21

MOSI → GPIO 20

MISO → GPIO 19

CS → GPIO 18 (chip-select that **actually** toggles under this overlay)

Once they aligned all of the above, `spi_test` and the W5500 driver started working immediately.

---

### **📘 WIZnet Insight**

Here’s what engineers often miss when using W5500 on Raspberry Pi:

**The Raspberry Pi 4 has multiple SPI bus options** (SPI0, SPI1, SPI5 depending on firmware).

**Not all CS pins are valid for all overlays.**
For example, `spi1-1cs` gives only one valid CS, while `spi1-3cs` maps CS0/1/2 to different GPIOs.

**If CS never toggles, the W5500 appears “dead”.**
The chip will not drive MISO unless CS is pulled low.

For stable operation, we strongly recommend:

SPI clock ≤ **30 MHz** (best compatibility)

Dedicated CS pin, avoid sharing with other SPI slaves

Confirm with logic analyzer if available (CS alignment is the #1 failure mode)

---

Source: https://maker.wiznet.io/jakelee/projects/how-one-raspberry-pi-user-solved-w5500-spi-configuration-issues-raspberry-pi-4-/