---
title: "Why Does the boneIO gen 2 DIN-Rail Dimmer Use a W5500 Instead of LAN8720?"
url: "https://maker.wiznet.io/Benjamin/resellers/why-does-the-boneio-gen-2-din-rail-dimmer-use-a-w5500-instead-of-lan8720/"
markdown_url: "https://maker.wiznet.io/Benjamin/resellers/why-does-the-boneio-gen-2-din-rail-dimmer-use-a-w5500-instead-of-lan8720/md"
type: "VAR: Value-Added Reseller Products"
author: "boneIO Sp. z o.o."
author_url: "https://store.boneio.eu/product/boneio-dimmer-led-gen-2/"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "boneIO Sp. z o.o."
original_url: "https://store.boneio.eu/product/boneio-dimmer-led-gen-2/"
license: "GNU General Public License, version 3 or later (GPL3+)"
published: "2026-08-27"
language: "en"
tags: ["W5500", "Home Assistant", "Home Automation"]
hardware: ["WIZnet W5500"]
likes: 0
views: 155
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# Why Does the boneIO gen 2 DIN-Rail Dimmer Use a W5500 Instead of LAN8720?

> boneIO's gen 2 dimmer moved to an ESP32-S3, which has no Ethernet MAC, so its shipping firmware declares a WIZnet W5500 on SPI in place of gen 1's LAN8720.

Original author: boneIO Sp. z o.o. (source: https://store.boneio.eu/product/boneio-dimmer-led-gen-2/)

## Components

- **WIZnet W5500** x 1: Declared at line 33 of boneio-dimmer_gen2_8ch-v0_1.yaml in the manufacturer repository github.com/boneIO-eu/esphome as ethernet: type: W5500. Attached to the ESP32-S3 over SPI at 25 MHz with clk GPIO1 ([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/))

## Documents and links

- [boneIO ESP Dimmer LED gen 2 product page](https://store.boneio.eu/product/boneio-dimmer-led-gen-2/) (code): Manufacturer store listing with SKU boneio_dimmer_led_gen2, EUR 115.13 including VAT, stock status and the full specification table
- [boneio-dimmer_gen2_8ch-v0_1.yaml shipping firmware configuration](https://github.com/boneIO-eu/esphome/blob/main/boneio-dimmer_gen2_8ch-v0_1.yaml) (schematics): The 308 line ESPHome configuration the product ships with. Lines 31 to 40 declare the W5500 and its SPI pin map. GPL-3.0
- [boneIO ESP firmware repository](https://github.com/boneIO-eu/esphome): All 21 firmware variants, the GitHub Actions build workflow and the release binaries. Created 30 July 2022, last push 15 June 2026, 22 stars and 24 forks
- [boneIO Dimmer LED gen 2 user manual, revision v2025/10](https://boneio.eu/manuals/dimmer_gen2_EN.pdf): Official 11 page English manual covering wiring, LED strip connection, RS485 and CAN terminals, fuses and technical data
- [ESP Dimmer gen2 overview and specification](https://boneio.eu/en/docs/esp/products/dimmer/gen2/overview): Manufacturer documentation with the specification table, connector descriptions and quick start guide
- [ESP Dimmer gen2 hardware installation guide](https://boneio.eu/en/docs/esp/products/dimmer/gen2/hardware_installation): DIN rail mounting, power supply wiring, Ethernet connection and the safety warnings about the USB-C port
- [UDP communication between boneIO ESP devices](https://boneio.eu/en/docs/esp/advanced/udp-communication): How two gen2 dimmers exchange input and sensor states over UDP broadcast on port 18511 without Home Assistant or a broker
- [boneIO Black versus ESP comparison](https://boneio.eu/en/docs/esp/introduction/comparison): Manufacturer comparison of the two controller families, including the note that Wi-Fi is not recommended inside a metal distribution board
- [ESPHome firmware release esphome-2026.5.3-b1](https://github.com/boneIO-eu/esphome/releases/tag/esphome-2026.5.3-b1): Release of 15 June 2026 with 42 binaries including boneio-dr-gen2-8ch-01-esp32s3.factory.bin for this product
- [ESPHome ethernet component documentation](https://esphome.io/components/ethernet/): Reference showing LAN8720 as RMII and ESP32 only, and W5500 as an SPI chip supported on ESP32 and RP2040
- [boneIO company profile and history](https://boneio.eu/en/about): Company origin, milestone timeline from 2021 to 2025, team members and the Łódź registered address
- [boneIO dimmer LED gen 2 at Botland](https://botland.com.pl/boneio-automatyka-domowa/28875-boneio-dimmer-led-gen-2-sterownik-oswietlenia-led-home-assistantesphome-5906530114215.html): Independent Polish distributor listing under index BIO-28875 and EAN 5906530114215 at 499,90 zl gross
- [WIZnet W5500](https://docs.wiznet.io/Product/Chip/Ethernet/W5500): Datasheet and documentation for the hardwired TCP/IP Ethernet controller used on the gen2 boards

## Article

## 📌 The ESP32-S3 in gen 2 Has No Ethernet MAC, Which Rules Out the LAN8720

The boneIO ESP Dimmer LED gen 2 declares `type: W5500` in its shipping firmware because the ESP32-S3 it moved to has no internal Ethernet MAC. A plain ESP32 has one, which let the first-generation dimmer drive an RMII PHY such as the LAN8720 over MDC, MDIO and a clock pin, and ESPHome's ethernet component documentation lists LAN8720 as "RMII, ESP32 only" against W5500 as an SPI part for ESP32 and RP2040. The same swap repeats across every gen2 product boneIO sells.

boneIO is a hardware company in Łódź, Poland whose About page puts the origin plainly: "boneIO started as a DIY project for Maciej's home and evolved into a complete open source smart home solution." The gen 2 dimmer is the newest device in its ESP line, an 8-channel PWM LED dimmer occupying 7 modules on a 35 mm DIN rail inside an electrical cabinet.

![Angled 3D render of a grey seven-module DIN rail enclosure labelled boneIO dimmer LED gen2, showing orange screw terminals for eight digital inputs, printed RS485 and CAN terminal labels, a USB-C socket and an RJ45 jack marked LAN](https://maker.wiznet.io/upload/ckeditor5/847907827%5F1787839757%2Epng) *The gen2 dimmer as boneIO shows it. This is a 3D render published by boneIO on its store, not a photograph. Source: store.boneio.eu.*

## Vendor, Availability, and Price

The seller and manufacturer is boneIO Sp. z o.o., a Polish limited company registered in August 2022 under NIP 7272861352 at Aleja Tadeusza Kościuszki 101, 90-441 Łódź, trading from its own WooCommerce store at store.boneio.eu since March 2023, with support through a contact form, the Discourse forum at forum.boneio.eu and a Discord server. The About page credits Maciej Krasuski with the product idea, Kamil Bożyk with electronics and Paweł Szafer with software; Szafer signs the firmware commits on GitHub as `pszafer`.

The dimmer is a direct purchase rather than a request-for-quote product. On 27 August 2026 the store page listed EUR 115.13 including VAT and EUR 93.60 excluding VAT under SKU `boneio_dimmer_led_gen2`, with an Add to cart button, "In stock", 110 units on the counter, "Shipping within 3 business days" and free delivery above 500 PLN. The embedded schema.org offer repeats `price: 93.60`, `availability: InStock` and `priceValidUntil: 2027-12-31`; the page was published on 7 October 2025 and last modified on 27 August 2026.

Botland, a Polish electronics distributor, is the only independent sales channel, listing the device under index BIO-28875 and EAN 5906530114215 at 499,90 zł gross and 406,42 zł net, though it showed zero units on 27 August 2026. No warranty period, return window or CE declaration was found on either page, so none is claimed here.

## What Changed Between the First-Generation Dimmer and gen 2

boneIO announced the gen2 dimmer on its own forum on 8 November 2025, writing that this is not a facelift but a completely redesigned device. The store copy names the new processor directly: "Featuring the new ESP32-S3 processor and RS485/CAN buses, the device now offers expanded capabilities for controlling external peripherals." The launch post also records a subtraction: gen2 drops the energy metering of the first generation to concentrate on lighting and the new serial buses.

![Side by side comparison of the first generation boneIO Dimmer LED on ESP32 with LAN8720 over RMII and the generation 2 dimmer on ESP32-S3 with a WIZnet W5500 over SPI, listing prices, per-channel current and the exact configuration file and line number for each Ethernet declaration](https://maker.wiznet.io/upload/ckeditor5/847907827%5F1787839757%5F0%2Epng) *Generated technical diagram, built for this article from the two configuration files in github.com/boneIO-eu/esphome, the two store listings, and the gen1 and gen2 overview pages on boneio.eu, all read on 27 August 2026.*

## ⚙️ Role of the W5500 on the ESP32-S3 Board

In `boneio-dimmer_gen2_8ch-v0_1.yaml` on the main branch of github.com/boneIO-eu/esphome, lines 31 to 40 hold the whole `ethernet:` block: `type: W5500`, `clk_pin: GPIO13`, `mosi_pin: GPIO39`, `miso_pin: GPIO38`, `cs_pin: GPIO12`, `interrupt_pin: GPIO2`, `reset_pin: GPIO1` and `clock_speed: 25MHz`. Line 11 sets the ESPHome project name to `boneio.dimmer-led-gen2` and line 27 the board to `esp32-s3-devkitc-1`, tying the file to the product on sale rather than to a prototype.

![GitHub source view of boneio-dimmer_gen2_8ch-v0_1.yaml with lines 31 to 40 highlighted, showing the ethernet block declaring type W5500 with clk_pin GPIO13, mosi_pin GPIO39, miso_pin GPIO38, cs_pin GPIO12, interrupt_pin GPIO2, reset_pin GPIO1 and clock_speed 25MHz below the esp32 board line reading esp32-s3-devkitc-1](https://maker.wiznet.io/upload/ckeditor5/847907827%5F1787839757%5F1%2Epng) *The *`*ethernet:*`* block on the main branch, captured 27 August 2026. The file's last commit is 82ec7c0, "fix yaml validation", dated 17 February 2026. Screenshot: github.com/boneIO-eu/esphome.*

The ESP32-S3 generates all eight dimming waveforms itself through ESPHome `ledc` outputs at 1000 Hz on GPIO 18, 17, 16 and 15 for the left section and GPIO 7, 6, 5 and 4 for the right, so lighting timing never crosses the network. The W5500 carries everything else: the ESPHome native API to Home Assistant, an on-device `web_server` on port 80, over-the-air updates, and the UDP transport on port 18511 that lets a wall switch on one dimmer toggle a channel on another with no broker in between.

![Diagram of the data path from eight wall inputs through a PCF8574 expander and the ESP32-S3 to a highlighted WIZnet W5500 on SPI at 25 MHz and out to the local network, with three cards below describing the PWM outputs, the traffic that crosses the RJ45, and the Modbus and CAN buses](https://maker.wiznet.io/upload/ckeditor5/847907827%5F1787839757%5F2%2Epng) *Generated technical diagram, built for this article. Every pin number and component name is taken from the shipping configuration file.*

The shipping configuration contains no `wifi:` block at all, so the W5500 link is the only network interface the factory firmware brings up even though the ESP32-S3 has a radio. ESPHome attaches the W5500 through the ESP-IDF `esp_eth` driver with lwIP handling TCP and UDP, so the chip's hardware socket engine goes unused here.

## Eight Inputs, Two Isolated Sections and Two Serial Buses

The eight digital inputs arrive through a PCF8574 I2C expander at 0x38 on SDA GPIO10 and SCL GPIO11, so the configuration file declares each one as a `pcf8574` pin.

![Front-facing 3D render of the boneIO dimmer LED gen2 showing green screw terminals for PSU L, CHL 1 to CHL 4, CHR 1 to CHR 4 and PSU R along the top, and orange terminals for POWER, VDD, IN 01 to IN 08, RS485 A+ B- GND, CAN L and H, USB and LAN along the bottom](https://maker.wiznet.io/upload/ckeditor5/847907827%5F1787839757%5F3%2Epng) *The labelled connector face. Render published by boneIO, not a photograph. Source: store.boneio.eu.*

The store specification table records 12-24 V DC in, maximum 7 W excluding the strips, 24 V DC out at 10 A per side across four channels, 126 x 91 x 57 mm without plugs and 230 g. Each independently powered section takes a 10 A fuse and a 200 W maximum load, a single channel is rated for 50 W, and an LM75B sensor sounds the on-board buzzer above 70 degrees Celsius.

RS485 and CAN appear only in the user manual, revision v2025/10, since the store table lists just "Ethernet 10/100Mbit" and USB-C under Communication. The manual describes the "CAN Port: Used for communication in a tree topology with other boneIO devices or for polling sensors operating with a CAN bus compatible protocol", while in firmware RS485 works out of the box through the `uart` and `modbus` components and CAN is only a GPIO35 transceiver standby switch with no `canbus:` component.

![Cutaway 3D render showing the interior of the dimmer enclosure with a blue printed circuit board, electrolytic capacitors, a red jumper and green output terminals visible through the open top of the case](https://maker.wiznet.io/upload/ckeditor5/847907827%5F1787839757%5F4%2Epng) *boneIO's cutaway view of the assembly. This is a render rather than a teardown photograph, and no chip markings are legible in it. Source: store.boneio.eu.*

## Where the gen2 Dimmer Sits in the boneIO ESP Catalogue

boneIO runs two controller families and only the ESP line touches WIZnet, since the Black line runs a modified Debian 13 build rather than compiled ESPHome firmware. The ESP category on store.boneio.eu held eight products on 27 August 2026, and every price, stock count and chip value in this section was read that day from the store and from each product's own `ethernet:` block.

| Product | MCU | Ethernet controller | Store status on 27 Aug 2026 |
| --- | --- | --- | --- |
| ESP Dimmer LED gen 2 | ESP32-S3 | W5500 over SPI | EUR 115.13, 110 in stock |
| ESP Input24 gen2 | ESP32-S3 | W5500 over SPI | EUR 115.13, 13 in stock |
| ESP 8x10A gen2 | ESP32-S3 | W5500 over SPI | EUR 126.12, out of stock |
| Dimmer LED, first generation | ESP32 | LAN8720 over RMII | EUR 100.74, out of stock |
| ESP Cover Mix | ESP32 | LAN8720 over RMII | EUR 467.77, 10 in stock |
| ESP Cover | ESP32 | LAN8720 over RMII | EUR 467.77, out of stock |
| ESP 32x10A | ESP32 | LAN8720 over RMII | EUR 467.77, out of stock |
| ESP 24x16A | ESP32 | LAN8720 over RMII | EUR 467.77, out of stock |

![Table of the eight boneIO ESP products listing product name, MCU, Ethernet controller, the ESPHome configuration file each one is built from, and the store price and stock status on 27 August 2026, with the three ESP32-S3 and W5500 rows highlighted](https://maker.wiznet.io/upload/ckeditor5/847907827%5F1787839757%5F5%2Epng) *Generated technical diagram, built for this article. The image adds the exact configuration file name behind each row, for example boneio-dimmer_gen2_8ch-v0_1.yaml for the gen2 dimmer.*

Seven of the 22 configuration files on the main branch declare W5500 and every one targets an ESP32-S3 board: the dimmer gen2 in its 8 channel, 4 CCT and 2xRGBW builds, Input24 gen2, and three 8x10A gen2 builds. The remaining fifteen declare LAN8720 and target a plain ESP32, either `esp32dev` or `nodemcu-32s`.

The boneIO ESPHome repository's GitHub Actions workflow builds 21 firmware variants from the YAML files a customer can read, and the release tagged `esphome-2026.5.3-b1` on 15 June 2026 attaches 42 binaries, among them `boneio-dr-gen2-8ch-01-esp32s3.factory.bin` at 680,240 bytes, matching the `substitutions.name` value at the top of the gen2 dimmer configuration.

## Setup Without Wi-Fi Provisioning

ESPHome's Made for ESPHome guidelines demand Improv provisioning components so a user can enter Wi-Fi credentials, then note that "these are not required for projects that only provide a physical/wired Ethernet port for connectivity." A device whose only interface is the W5500 plugs into a switch, takes a DHCP lease and appears, which is why the store page can say the dimmer ships with ESPHome pre-installed and joins Home Assistant automatically. Lines 115 and 116 of `boneio-dimmer_gen2_8ch-v0_1.yaml` carry the matching `dashboard_import` entry pointing at that file on the main branch.

boneIO's philosophy page states that "boneIO devices are designed to work 100% within your local network", and its Black versus ESP comparison adds a footnote that Wi-Fi in a closed metal distribution board is not recommended because of strong signal attenuation. A 7-module DIN device lives inside exactly that kind of cabinet.

## Related WIZnet Maker Projects

[KinCony KC868-A2v3: A W5500-Based ESP32-S3 Relay Controller Built for Wired-First Automation](https://maker.wiznet.io/ElenaLee/resellers/kincony-kc868-a2v3-a-w5500-based-esp32-s3-relay-controller-built-for-wired-first-automation/) is the same transition seen from China rather than Poland: KinCony also moved from a LAN8720A PHY to a W5500 when its v3 boards adopted the ESP32-S3, which makes boneIO's gen2 change a pattern rather than a one-off vendor preference.

[ESP32S3 Dimmer Module, DM8 8CH Dimmer](https://maker.wiznet.io/bruno/resellers/esp32s3-dimmer-module--dm8-8ch-dimmer/) is the closest functional twin, another 8-channel ESP32-S3 dimmer for Home Assistant that also carries a W5500, but the DM8 sends 0-10 V to external LED drivers and keeps Wi-Fi beside its wired port, whereas the boneIO device switches the strips directly with PWM and ships wired-only firmware.

[OpenKNX REG1: A Bus-Powered DIN-Rail KNX-IP Router on RP2040 and W5500](https://maker.wiznet.io/Benjamin/resellers/openknx-reg1-a-bus-powered-din-rail-knx-ip-router-on-rp2040-and-w5500/) occupies the same 35 mm rail with a W5500 doing the same job, but through open hardware and the KNX standard rather than closed hardware with open firmware.

## ❓ FAQ

**Q. Which WIZnet chip does the boneIO ESP Dimmer LED gen 2 use, and where is that documented?** The W5500, declared at line 33 of `boneio-dimmer_gen2_8ch-v0_1.yaml` in the manufacturer's own repository at github.com/boneIO-eu/esphome. Neither the store specification table nor the user manual names the chip.

**Q. How is the W5500 wired to the ESP32-S3?** Over SPI at 25 MHz, on GPIO13 clk, GPIO39 mosi, GPIO38 miso, GPIO12 chip select, GPIO2 interrupt and GPIO1 reset. Those six pins plus the clock speed are the complete `ethernet:` block in the shipping configuration.

**Q. Why did boneIO drop the LAN8720 that the first-generation dimmer used?** The first generation ran on an ESP32, whose internal Ethernet MAC can drive an RMII PHY, while gen2 runs on an ESP32-S3 with no Ethernet MAC. ESPHome's ethernet component lists LAN8720 as ESP32 only and W5500 as an SPI part, so an SPI controller is what keeps the wired port.

**Q. Can the device work without a Home Assistant server?** Yes for local logic and device-to-device links, since ESPHome runs the automations on the device and boneIO documents UDP transport on port 18511 for one dimmer to drive another over the LAN. Home Assistant remains where dashboards, voice control and cross-device scenes live.

**Q. What does it cost and can it be bought right now?** EUR 115.13 including VAT or EUR 93.60 excluding VAT direct from store.boneio.eu, which showed 110 units in stock and a three business day dispatch window on 27 August 2026. Botland lists the same EAN 5906530114215 at 499,90 zł gross but showed no stock on that date.

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Source: https://maker.wiznet.io/Benjamin/resellers/why-does-the-boneio-gen-2-din-rail-dimmer-use-a-w5500-instead-of-lan8720/