--- title: "A Matter Water-Tank Controller That Never Drops: W5500 Wired/Wi-Fi Redundancy" url: "https://maker.wiznet.io/Grace_Koo/projects/relay-2way--matter-/" markdown_url: "https://maker.wiznet.io/Grace_Koo/projects/relay-2way--matter-/md" type: "UCC: User Created Content" author: "Billtou" author_url: "https://github.com/Billtou/public" editor: "WIZnet" editor_url: "https://maker.wiznet.io/" original_author: "Billtou" original_url: "https://github.com/Billtou/public" published: "2026-06-25" language: "en" hardware: ["WIZnet W5500"] likes: 0 views: 178 comments: 0 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # A Matter Water-Tank Controller That Never Drops: W5500 Wired/Wi-Fi Redundancy > Matter water-tank refill controller on ESP32-S3 with WIZnet W5500 — wired-first Ethernet, auto Wi-Fi fallback. Works with Apple, Google, HA, Alexa. Original author: Billtou (source: https://github.com/Billtou/public) ## Components - **WIZnet W5500** x 1 ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5500)) 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/)) ## Article ## Water Keeps Flowing Even When the Power or Wi-Fi Drops — WL-01, a Matter Water-Tank Controller Built on W5500 Wired/Wireless Redundancy --- ### One-Line Summary > A Matter water-tank auto-refill controller that pairs WIZnet W5500 wired Ethernet with Wi-Fi on an ESP32-S3, guaranteeing an unbroken connection through wired-first operation with automatic wireless fallback. It connects to Apple Home, Google Home, Home Assistant, and Alexa simultaneously. --- ### What Is This Project? WL-01 is a **water-tank auto-refill controller** from the AUTOMATE brand. An ultrasonic level sensor reads the tank level; when the water drops below a set refill line, the controller runs the pump to refill automatically, then stops at the full line. The heart of this product isn't the refill automation itself — it's **connection reliability**. Because it's an always-on piece of equipment, a dropped network is a real problem. WL-01 solves this by making **W5500 wired Ethernet and Wi-Fi redundant**. On top of that, Matter support lets it connect to every major smart-home platform at once, with no dedicated hub. #### About the Repository This article is based on the GitHub repository `Billtou/public`. The repository holds **not source code, but the distribution and support materials for the WL-01 product, released under the AUTOMATE brand**. It contains three main things: - **Firmware binaries (**`**.bin**`**)** — version-stamped executables accumulated over time (currently up to v0.2.9) - **OTA manifests** — config files that let the device pull the latest firmware automatically - **User manual (**`**README.md**`**)** — covering specs, wiring, pairing, setup, and troubleshooting In other words, it isn't something to "read the code and build from" — it's best seen as a **technical case study of how a product-grade controller combined W5500 wired/wireless redundancy with Matter**. The fact that firmware has climbed steadily to v0.2.9 shows it's a still in active development and maintenance. --- ### What WIZnet Brings: The Lifeline of a Device That Must Not Disconnect A water-tank refill controller is a device that **must stay powered on and connected at all times**. You need to check and control it remotely while away from home or out of the country — and if the network is down at that moment, the device is meaningless. This is where the WIZnet **W5500** plays its key role. #### Why Wi-Fi Alone Isn't Enough Wi-Fi is convenient, but in equipment environments it carries many sources of instability — router reboots, channel interference, weakening signal, DHCP lease-renewal failures, and so on. For a device controlling core infrastructure like a building's water tank, that instability is fatal. WL-01 solves this by making W5500 wired Ethernet the **primary** connection. Whenever a LAN cable is plugged in, wired is always used first; Wi-Fi is dropped and only comes back automatically when the wired link fails. #### Wired-First + Automatic Wireless Fallback WL-01's network-switching logic works as follows. ![](https://maker.wiznet.io/upload/ckeditor5/638031642%5F1782467896%2Epng) | State | Behavior | | --- | --- | | Cable only | Use W5500 wired, block Wi-Fi | | Wi-Fi only | Use Wi-Fi (Matter pairing goes through BLE) | | Both present | **Wired first**, Wi-Fi auto-blocked to save power | | Wired lost | **Auto-fallback to Wi-Fi, Matter connection uninterrupted** | | Wired restored | Back to wired, Wi-Fi blocked | This "turn wireless off while wired is alive, bring wireless up when wired dies" default-route switching is the core of WL-01's reliability — and W5500 carries that wired axis. #### How W5500 Is Connected W5500 connects to the ESP32-S3 over SPI and provides 10/100 Mbps wired Ethernet. Because W5500 embeds its TCP/IP stack in hardware, it secures a stable wired link while easing the load on the ESP32-S3. This becomes the network foundation that Matter communication, the local Web UI, and OTA updates all depend on. --- ### How It Works: From Sensor to Smart Home WL-01's overall operation breaks into three axes. **1) Level Sensing (ModBus RS485)** An ultrasonic level sensor connects over ModBus RTU (RS485). It measures a 0.75–3 m range and derives a stable level by averaging multiple readings. If the sensor disconnects, the system automatically enters an "abnormal" mode and force-stops the motor to prevent the pump from running dry. **2) Auto-Refill Logic** ![](https://maker.wiznet.io/upload/ckeditor5/638031642%5F1782468217%2Epng) **3) Network & Smart Home (W5500 + Wi-Fi + Matter)** It runs the Matter protocol on top of the W5500/Wi-Fi redundancy. Matter's Multi-Admin feature lets it connect to up to five ecosystems (Apple Home, Google Home, Home Assistant, Alexa) at once — set it up once and state syncs across multiple apps. The device exposes five Matter entities. | Entity | Endpoint | Role | | --- | --- | --- | | Automation | EP1 | ON = auto mode / OFF = stop mode (motor force-off) | | Refill | EP2 | Mirrors motor state; ON = start refill | | Aux Relay (Relay 02) | EP3 | Directly controls a separate GPIO relay (no safety logic) | | Level Sensor | EP4 | Borrows the humidity cluster to show 0–100% level | | Abnormal Alert | EP5 | Borrows a Contact sensor; Closed = normal / Open = abnormal, triggers push notifications | A 128×64 SH1106 OLED shows the current state (auto/stop/refill/abnormal) and level data in real time, and physical buttons allow manual control even without a network. --- ### What's Worth Noting - **A textbook network design for an "always-on device"**: A tank refiller is equipment that can't drop its connection for even a moment. Making W5500 wired the primary and Wi-Fi the backup is a model structure for this kind of mission-critical IoT. It directly implements the highest-value combination from an evaluation standpoint: "the stability of wired + the convenience of wireless." - **Combining Matter + W5500**: It's distinctive in carrying Matter traffic — the core smart-home standard of 2026 — over wired (Ethernet) as the first-priority transport rather than wireless. With Matter over Wi-Fi being the norm, devices that put Ethernet first are rare. See the section "Carrying Matter Traffic over Wired (Ethernet) as First Priority" below for details. - **A finished, commercially sold product**: Firmware v0.2.9, automatic OTA updates, OEM white-label capability, and Multi-Admin support across five ecosystems — this is a product-grade, finished design, not a sample, built to product level. - **Industrial sensor integration**: By integrating a ModBus RTU RS485 ultrasonic sensor, it reaches beyond typical smart-home gear into equipment-automation territory. - **Safety-oriented design**: Motor defaults to OFF after power is restored, force-stop on sensor anomaly — the pump-protection logic is thorough. --- ### Use Cases - **Home / building water-tank auto-refill**: Automatically manage rooftop tank levels and check or control status from a phone while away - **Agricultural reservoir management**: Auto-replenish irrigation reservoirs on a smart farm with instant alerts on anomalies - **Commercial-facility water management**: Monitor multiple tanks centrally from a building office via Home Assistant - **Equipment rooms with wired infrastructure**: Leverage wired stability directly in cabled machine and pump rooms - **Any auto-refill setting where network reliability matters**: Wi-Fi if wired drops, safe even through a power outage --- ### Carrying Matter Traffic over Wired (Ethernet) as First Priority Matter is an **application-layer protocol** through which smart-home devices exchange commands and state. But Matter doesn't fix which physical path (the transport layer) carries those messages — it allows all three of **Wi-Fi, Thread, and Ethernet**. WL-01's most technically distinctive choice is carrying this Matter traffic over **wired (Ethernet) as the first-priority transport** rather than wireless. Market Matter devices are essentially all Wi-Fi or Thread, and devices that put Ethernet first are very rare. WL-01 layers Matter on top of a **dual-transport structure** with W5500 wired as the primary path and Wi-Fi as backup. This design brings four practical benefits. - **Separation of commissioning and operation**: Initial pairing goes through BLE, but once paired, day-to-day communication shifts straight to W5500 Ethernet whenever a cable is present. Even in equipment rooms with messy wireless conditions, you can pair briefly over wireless and run operations over stable wired. - **Uninterrupted path switching**: Even as wired↔Wi-Fi switch automatically, the Matter session (Fabric) is preserved. The device stays continuous as seen from the app, and the user never notices the switch. - **mDNS local discovery**: Exposed under the hostname `automate-wl01-XXXXXX.local`, it's discovered and controlled locally — without the cloud — on the same network, wired or wireless. Matter's local-first philosophy meets wired stability here. - **Synergy with Multi-Admin**: Stable wired backs the traffic of up to five ecosystems (Apple/Google/HA/Alexa) controlling the same device at once. When multiple hubs poll and control simultaneously, wired beats wireless on latency and packet loss. In short, putting "Matter over Ethernet first, with Wi-Fi as automatic fallback" is a design rarely seen on the market, achieving at once the reliability an always-on equipment device demands and the multi-ecosystem convenience of Matter. --- ### Tech Stack Summary | Item | Details | | --- | --- | | **MCU** | ESP32-S3-WROOM-1-N4 | | **Ethernet chip** | **WIZnet W5500** (SPI, 10/100 Mbps, hardware TCP/IP) | | **Network redundancy** | W5500 wired (primary) + Wi-Fi 2.4 GHz (backup), wired-first auto-fallback | | **Smart-home standard** | Matter 1.x over Wi-Fi/Ethernet, Multi-Admin up to 5 Fabrics | | **Compatible platforms** | Apple Home, Google Home, Home Assistant, Amazon Alexa (no dedicated hub) | | **Level sensor** | Ultrasonic ModBus RTU RS485 (0.75–3 m) | | **Relays** | 2-channel, up to 10 A 250 VAC (motor + aux) | | **Power** | DC 12 V / 1 A | | **Brand / Firmware** | AUTOMATE (brand), v0.2.9 | --- ### FAQ **Q. Which takes priority, wired or Wi-Fi?** Wired (W5500 Ethernet) always takes priority. When a cable is plugged in and connected, Wi-Fi automatically drops to save power. Only when the wired link fails does Wi-Fi auto-switch in as backup — and the Matter connection stays up through that switch. **Q. Does W5500 use a hardware TCP/IP stack?** Yes. W5500 is a controller that embeds its TCP/IP stack in hardware inside the chip. The ESP32-S3 talks to W5500 over SPI, securing a stable wired link at low overhead. That wired link becomes the common foundation for Matter communication, the local Web UI, and OTA. **Q. Does Matter require a separate hub?** No. Because WL-01 supports the Matter standard, it connects directly to Apple Home, Google Home, Home Assistant, and Alexa without a dedicated hub. With Multi-Admin, it can connect to up to five ecosystems at once. **Q. If the network goes down completely, does it stop working?** No. The core auto-refill logic (level sensing → motor control) runs inside the device, independent of the network. Manual refill/stop is also possible via physical buttons. The network is for remote monitoring, control, and alerts — refilling itself continues even if it drops. **Q. If the sensor fails, does the pump keep running?** No. If the level sensor fails to read repeatedly, the system automatically enters "abnormal" mode and force-stops the motor. This is a safety design that prevents the pump from running dry and burning out. At the same time, the Matter Contact sensor goes "Open," sending a push notification to your phone. --- > **Project Links** > > - GitHub: [Billtou/public — WL_01b](https://github.com/Billtou/public/tree/main/WL_01b) > > - WL-01 Matter manual: [WL_01b/matter/README.md](https://github.com/Billtou/public/blob/main/WL_01b/matter/README.md) > > - WIZnet W5500: https://docs.wiznet.io/Product/Chip/Ethernet/W5500 --- Source: https://maker.wiznet.io/Grace_Koo/projects/relay-2way--matter-/