---
title: "40-way Ethernet Digital I/O extension for Loxone"
url: "https://maker.wiznet.io/WIZnet/projects/40-way-ethernet-digital-i-o-extension-for-loxone/"
markdown_url: "https://maker.wiznet.io/WIZnet/projects/40-way-ethernet-digital-i-o-extension-for-loxone/md"
type: "UCC: User Created Content"
author: "andrew.crockford"
author_url: "https://hackaday.io/project/27814-40-way-ethernet-digital-io-extension-for-loxone"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "andrew.crockford"
original_url: "https://hackaday.io/project/27814-40-way-ethernet-digital-io-extension-for-loxone"
published: "2023-02-09"
language: "en"
hardware: ["WIZnet W5100 ethernet shield"]
likes: 2
views: 374
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# 40-way Ethernet Digital I/O extension for Loxone

> This project shows how to build a low cost reliable 40-way digital input or output board- designed to integrate with the loxone mini-server.

Original author: andrew.crockford (source: https://hackaday.io/project/27814-40-way-ethernet-digital-io-extension-for-loxone)

## Components

- **WIZnet W5100 ethernet shield** x 1 ([docs](https://www.wiznet.hk/en/open-source-hardware/102-w5100s-ethernetshield.html?search_query=W5100+ethernet+shield&results=84))

## Article

I’ve nearly completed building my own home, and have used the loxone mini-server to supply the home automation. When specifying the server, we quickly realised we would have to find another solution for all the digital io.
We have 43 light switches – but each light switch has 4 contacts – making 172 inputs just for the light switches. Add to that 20 door & window sensors, plus blind controls, PIR sensors, under floor heating actuators and pumps. You get the idea.
I chose the teensy 2.0++ as it had a large number of digital IO on the board. We did consider using I2C io extension boards, but physical size is a factor and it was easier for us to make it compact using the teensy.
I’m not a hardware expert at all! But the system we have made is bullet proof reliable. The software and interface to the loxone does not use any polling at all- so all the double/triple clicks work flawlessly with the loxone system.
The boards have a web interface which is really important for setting up and diagnostics as you have feedback showing which inputs or outputs are active.

In our build we have 2 sub-boards each with 4 nodes – making a total of 8 nodes with a capacity for 320 i/o. Each sub board has it’s own 5v 5 port switch, and a POE splitter – the whole board being run by 1 port on my POE switch.

It was a challenge to get 40 I/O available on the teensy 2.0. We needed 4 pins for the ethernet connection & 1 pin for the on-board LED. Using the teensy’s interior pins, and re-purposing one of the UART pins we were able to have 40 pins usable for io. The UART pin needed an external pull-up resistor to make it usable for normal io.

## **FILES**

| ### [**teensy_switch_2.zip**](https://cdn.hackaday.io/files/278141189994176/teensy_switch_2.zip) Arduino teensy++ 2.0 source code x-zip-compressed – 18.17 kB – 05/30/2020 at 10:04 |  | [Download](https://cdn.hackaday.io/files/278141189994176/teensy_switch_2.zip) |
| --- | --- | --- |
| ### [**DigitalIOCase.skp**](https://cdn.hackaday.io/files/278141189994176/DigitalIOCase.skp) Sketchup model for the frame mount SSEYO Koan Play File – 109.65 kB – 10/21/2017 at 10:14 |  | [Download](https://cdn.hackaday.io/files/278141189994176/DigitalIOCase.skp) |
| ### [**DigitalIOCase.stl**](https://cdn.hackaday.io/files/278141189994176/DigitalIOCase.stl) STL model for the frame mount Standard Tesselated Geometry – 56.72 kB – 10/21/2017 at 10:14 |  | [Download](https://cdn.hackaday.io/files/278141189994176/DigitalIOCase.stl) |

---

Source: https://maker.wiznet.io/WIZnet/projects/40-way-ethernet-digital-i-o-extension-for-loxone/