--- title: "Walter Unified Communications Library" url: "https://maker.wiznet.io/bruno/projects/walter-unified-communications-library/" markdown_url: "https://maker.wiznet.io/bruno/projects/walter-unified-communications-library/md" type: "UCC: User Created Content" author: "walter-uc" author_url: "https://github.com/QuickSpot/walter-uc" editor: "WIZnet" editor_url: "https://maker.wiznet.io/" original_author: "walter-uc" original_url: "https://github.com/QuickSpot/walter-uc" published: "2026-10-26" language: "en" likes: 0 views: 11 comments: 0 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # Walter Unified Communications Library > Walter-UC: Unified IoT Connectivity with W5500 Ethernet, Wi-Fi, and Cellular Original author: walter-uc (source: https://github.com/QuickSpot/walter-uc) ## Article ## Walter-UC: Adding W5500 Wired Ethernet to a Multi-Radio IoT Platform **A wireless-first IoT platform extended with wired Ethernet through the WIZnet W5500.** ![이미지 미리 보기](https://maker.wiznet.io/upload/ckeditor5/7fc5c7f36d3d47a48459eb8b06bfe6db.png) ### Overview QuickSpot's Walter is a compact IoT module powered by an ESP32-S3 microcontroller and a Sequans GM02SP cellular modem. It supports LTE-M, NB-IoT, Wi-Fi, Bluetooth Low Energy, and GNSS. Although Walter is primarily designed for wireless connectivity, some IoT deployments benefit from a wired network connection. **Walter Unified Communications (Walter-UC)** addresses this requirement by integrating an external WIZnet W5500 SPI Ethernet interface into its multi-network communication architecture. The result is an open-source reference for developers who want to combine wired Ethernet with Wi-Fi and cellular connectivity in a single IoT application. ### Why Add the W5500? The WIZnet W5500 enables Ethernet connectivity through an SPI interface, allowing developers to add a wired network connection without redesigning Walter around a built-in Ethernet port. This is particularly useful for fixed-location IoT devices, industrial monitoring equipment, and sensor gateways connected to existing Ethernet infrastructure. **Walter does not have an onboard W5500 or RJ45 connector.** Developers must connect a separate W5500-based Ethernet module to the available GPIO pins. ![이미지 미리 보기](https://maker.wiznet.io/upload/ckeditor5/f6ef5232afbe45a3aa40f94c789ea27f.png) ### How Walter-UC Works Walter-UC provides a common networking architecture for three connection types: **W5500 Ethernet:** External wired Ethernet interface using ESP-IDF `esp_eth`. **Wi-Fi:** Wireless networking through the ESP32-S3. **Cellular:** LTE-M and NB-IoT networking through the Sequans GM02SP modem using PPP. The library monitors network interface availability and selects an active interface according to its configured priorities. Applications can continue using standard ESP-IDF networking APIs for MQTT, HTTP, and TCP/IP communication. For example, Ethernet can be configured as the preferred connection, while Wi-Fi and cellular remain alternative communication paths. When the active interface changes, existing connections may need to be re-established by the application. ### W5500 Driver Integration One of the most interesting aspects of Walter-UC for WIZnet developers is that W5500 support is included directly in the upstream project. The library provides: W5500 Ethernet driver integration through ESP-IDF. Configuration of SPI clock and GPIO assignments. Support for optional interrupt and reset connections. DHCP network configuration by default. Optional static IP configuration. Network interface selection based on priority and availability. The W5500 is the default external Ethernet module selected by the library's configuration menu. **Technical note:** This implementation uses the W5500 in MACRAW mode with the ESP32's software TCP/IP stack. It demonstrates Ethernet integration rather than W5500 hardware TCP/IP offloading. ### Potential Applications Walter-UC can serve as a reference architecture for several IoT applications: **Industrial monitoring:** Use wired Ethernet for equipment installed near an existing LAN, with wireless connectivity available as an alternative. **Remote sensor gateways:** Combine local Ethernet access with LTE-M or NB-IoT connectivity where appropriate. **Smart energy monitoring:** Connect fixed measurement equipment to a wired network while keeping other communication interfaces available. **Multi-network IoT devices:** Develop applications that can operate across different network interfaces without implementing separate networking APIs for every transport. These are potential application scenarios rather than independently verified Walter-UC installations. ### Getting Started Developers can explore the source code, Ethernet driver, configuration files, and example applications through the official repository. **Original project:** **W5500 configuration:** **Walter hardware and purchasing:** **Example W5500 Ethernet module:** ### Conclusion Walter-UC demonstrates how a wireless-first IoT platform can be expanded with wired Ethernet using the **WIZnet W5500**. By providing a common architecture for Ethernet, Wi-Fi, and cellular networking, the project offers a useful starting point for ESP32-S3 developers building devices that require multiple communication options. For WIZnet customers, it is a practical example of W5500 integration into an existing multi-radio IoT software platform. *Project developed by QuickSpot / DPTechnics. W5500 is a product of WIZnet. Hardware integration and application-specific connection recovery require developer configuration and validation.* --- Source: https://maker.wiznet.io/bruno/projects/walter-unified-communications-library/