Ethernet for RP2350A in Minutes: WeAct RP2350A_V20 + WIZnet W5500 (SPI Hardwired TCP/IP)

Turn the WeAct RP2350A_V20 into a wired IoT node using WIZnet W5500 over SPI—fast bring-up, stable Ethernet, and simple socket-based networking.

COMPONENTS Hardware components

WIZnet - W5500

x 1

WeAct Studio - WeAct Studio RP2350A_V20

x 1

Software Apps and online services

Raspberry Pi - Raspberry Pi OS

x 1

WIZnet - WIZnet io Library

x 1

PROJECT DESCRIPTION

Introduction

Let’s start with what we’re building.

The WeAct RP2350A_V20 is a small, affordable board based on Raspberry Pi’s RP2350A, with a Pico 2-style layout and a USB-C port.

But out of the box, it’s still a microcontroller board—so if you want reliable wired networking, you’ll usually add an Ethernet controller.

That’s where WIZnet W5500 comes in.

WIZnet Product Integration

The networking block is simple and proven:

RP2350A_V20 ↔ SPI ↔ WIZnet W5500 ↔ Ethernet.

W5500 is a “hardwired TCP/IP” Ethernet controller, so you don’t need to implement the full network stack in your MCU firmware.

You mostly talk to it through socket-style APIs—and you’re online.

Technical Implementation

Here’s what we’re combining:

RP2350A_V20 (RP2350A SoC)

Dual-core Arm Cortex-M33 or dual-core Hazard3 RISC-V, up to 150 MHz

520 KB SRAM

4 MB or 16 MB QSPI flash options

USB Type-C (USB 1.1 host/device) for power and programming

2×20-pin headers, with lots of GPIO and PIO capability

WIZnet W5500

SPI interface, embedded MAC+PHY

8 hardware sockets and 32 KB internal buffer

Wiring (practical, “just works” approach)

Use any free SPI peripheral on RP2350A and wire:

RP2350A SCK → W5500 SCK

RP2350A MOSI → W5500 MOSI

RP2350A MISO → W5500 MISO

RP2350A CS → W5500 CS

RP2350A 3V3 → W5500 3V3

RP2350A GND → W5500 GND

Optional but recommended:

RP2350A GPIO → W5500 RST (reset control)

RP2350A GPIO → W5500 INT (interrupt-driven networking)

Note: pin names vary by board definition—so pick pins that match your SDK/Arduino pin map.

Reproduction Guide

Let’s bring it up step by step.

Flash a simple “SPI + Ethernet” test firmware to the RP2350A_V20.

Confirm SPI is alive (optional, but saves time).

Initialize W5500 with your MAC address.

Start DHCP and print the assigned IP.

Run a quick client test (HTTP GET) or a tiny TCP server.

If you see an IP address on the serial monitor, you’re done.

Core Features and Performance

Here’s what you get immediately:

Stable wired Ethernet for deployments where Wi‑Fi is a risk

Fast bring-up: socket-based networking on top of W5500

Good fit for real products: RP2350 security + W5500 proven Ethernet

Code Snippet

Here’s the core logic pattern: SPI init, W5500 init, then DHCP.

#include <SPI.h>

#include <Ethernet.h>

// Pick a CS pin that matches your RP2350A_V20 wiring

static const int W5500_CS = 5;

byte mac[6] = { 0x02, 0x00, 0x23, 0x50, 0xA0, 0x01 }; // demo MAC

void setup() {

Serial.begin(115200);

while (!Serial) {}

Ethernet.init(W5500_CS);

if (Ethernet.begin(mac) == 0) {

Serial.println("DHCP failed. Check cable / link / CS pin / SPI wiring.");

for (;;) {}

}

Serial.print("IP: ");

Serial.println(Ethernet.localIP());

}

void loop() {

// Add your TCP/UDP application here

}

Once DHCP works, everything else is just your application protocol.

Applications and Extensions

A few real-world ways to use this combo:

Industrial sensors: reliable Ethernet + MCU simplicity

Building automation: long cable runs, centralized switching

Networked controllers: Modbus/TCP, simple TCP bridges, telemetry

Tiny edge nodes: local dashboards + data push

Extensions you might add:

(planned) interrupt-driven RX with W5500 INT for lower latency

(planned) static IP + watchdog recovery for unattended deployments

Conclusion

To wrap up: the WeAct RP2350A_V20 gives you a modern dual-architecture MCU platform, and WIZnet W5500 gives you a fast path to real Ethernet.

If you want a stable wired IoT node without wrestling with a full TCP/IP stack on the MCU, this is a clean, repeatable approach.

Try it with a W5500 module today, and turn your RP2350A project into a network-ready device.

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