---
title: "PoE-powered GPIB Adapter With Ethernet And USB-C Support"
url: "https://maker.wiznet.io/Benjamin/projects/poe-powered-gpib-adapter-with-ethernet-and-usb-c-support/"
markdown_url: "https://maker.wiznet.io/Benjamin/projects/poe-powered-gpib-adapter-with-ethernet-and-usb-c-support/md"
type: "UCC: User Created Content"
author: "Maya Posch"
author_url: "https://hackaday.com/2025/05/10/poe-powered-gpib-adapter-with-ethernet-and-usb-c-support/"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "Maya Posch"
original_url: "https://hackaday.com/2025/05/10/poe-powered-gpib-adapter-with-ethernet-and-usb-c-support/"
published: "2025-05-29"
language: "en"
tags: ["W5500", "PoE"]
hardware: ["WIZnet W5500"]
likes: 0
views: 3001
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# PoE-powered GPIB Adapter With Ethernet And USB-C Support

> Open-source GPIB-to-Ethernet adapter using W5500 chip. Supports PoE/USB-C power, VXI-11.2 & Prologix protocols. Cost-effective solution.

Original author: Maya Posch (source: https://hackaday.com/2025/05/10/poe-powered-gpib-adapter-with-ethernet-and-usb-c-support/)

## Components

- **WIZnet W5500** x 1 ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5500))
- Software: **PlatformIO Core** ([docs](https://docs.platformio.org/en/latest/core/index.html))

WIZnet parts: W5500 ([Datasheet](https://docs.wiznet.io/Product/Chip/Ethernet/W5500/datasheet?utm_source=maker&utm_medium=project&utm_campaign=w5500), [product hub](https://maker.wiznet.io/products/w5500/))

## Documents and links

- [PoE_Ethernet_GPIB_Adapter](https://github.com/Kofen/PoE_Ethernet_GPIB_Adapter) (code)

## Article

### **Project Overview**

The PoE Ethernet GPIB Adapter bridges the gap between legacy test equipment and modern network infrastructure. Using the Wiznet W5500 Ethernet controller, this open-source project transforms traditional GPIB/IEEE-488 instruments into network-accessible devices at a fraction of the cost of commercial solutions.

### **🎯 The Challenge**

Laboratory and industrial test equipment often uses GPIB (General Purpose Interface Bus) for automation and control. However, GPIB presents several challenges:

- **Bulky, expensive cables** that limit equipment placement

- **Limited cable length** (typically 20 meters maximum)

- **Single computer control** without network sharing

- **Commercial adapters cost $500+** per instrument

### **💡 The W5500 Solution**

This adapter leverages the Wiznet W5500's capabilities to create an affordable, reliable Ethernet-to-GPIB bridge:

**Key Features:**

- **Hardware TCP/IP Stack**: W5500 handles all network protocols, freeing the ATmega4809 for GPIB management

- **Dual Power Options**: Power over Ethernet (802.3af) or USB-C for maximum flexibility

- **Multiple Protocol Support**: Choose between VXI-11.2 (VISA compatible) or Prologix protocols

- **Web Interface**: Built-in web server on port 80 for configuration and basic instrument control

- **Cost-Effective**: Total BOM under $50 - one-tenth the price of commercial alternatives

### **🔧 Technical ImplementationHardware Architecture:**
The ATmega4809 microcontroller manages the GPIB bus interface while communicating with the W5500 via SPI. This separation of concerns allows:

- Reliable GPIB timing and handshaking

- Simultaneous network communication

- Support for up to 30 GPIB instruments (bus limitation)

- Network discovery via UDP broadcast

**Software Features:**

- **VXI-11.2 Mode**: Full VISA compatibility for seamless integration with existing test software

- **Prologix Mode**: Simple ASCII protocol for basic instrument control

- **Serial Console**: USB-based configuration and debugging interface

- **DHCP/Static IP**: Flexible network configuration options

### **📋 Use CasesLaboratory Automation:**

- Connect multiple instruments to a central network

- Enable remote access to expensive test equipment

- Share instruments between multiple workstations

**Industrial Testing:**

- Integrate legacy equipment into modern production lines

- Enable remote monitoring and control

- Reduce cabling complexity in test fixtures

**Education & Research:**

- Make lab equipment accessible to remote students

- Create virtual instrument pools

- Preserve vintage equipment functionality

### **🚀 Getting Started**

1. **Assemble the Hardware**: PCB design files and assembly instructions available on GitHub

2. **Flash the Firmware**: Use PlatformIO to compile and upload the code

3. **Connect Your Instrument**: Standard GPIB cable to your test equipment

4. **Network Configuration**: Access via serial console or DHCP assignment

5. **Start Testing**: Use VISA strings like `**TCPIP::192.168.1.100::gpib,5::INSTR**`

### **📊 Performance Specifications**

- **Network Interface**: 10/100 Mbps Ethernet via W5500

- **GPIB Speed**: Up to 1 MB/s (hardware dependent)

- **Latency**: < 5ms typical network response

- **Power Consumption**: < 2W (PoE) or 500mA @ 5V (USB-C)

- **Temperature Range**: 0-70°C operating

### **🔍 W5500 Advantages in This Application**

The Wiznet W5500 proves ideal for this project because:

- **Offloads TCP/IP Processing**: The ATmega4809 can focus entirely on GPIB protocol handling

- **Multiple Socket Support**: Enables web server alongside instrument communication

- **SPI Interface**: Simple 4-wire connection leaves GPIO pins for GPIB control

- **Proven Reliability**: Hardware TCP/IP stack eliminates software TCP/IP bugs

- **Low Power**: Compatible with PoE power budgets

### **✅ Project Impact**

This open-source design democratizes test equipment connectivity. By reducing the adapter cost from 500to50, it enables:

- Small labs to network their equipment

- Hobbyists to automate measurements

- Educational institutions to modernize legacy instruments

- Industry to extend equipment lifespan

### **🛠️ Future Enhancements**

- mDNS support for easier discovery

- Enhanced web interface with graphing capabilities

- Support for GPIB analyzers and bus monitoring

- Integration with cloud-based test platforms

---

**Join the community on EEVBlog forums or contribute to the GitHub repository to help modernize test equipment worldwide!**

---

Source: https://maker.wiznet.io/Benjamin/projects/poe-powered-gpib-adapter-with-ethernet-and-usb-c-support/