iono: a new professional input/output DIN-rail module based on Arduino

iono allows you to use your Arduino programming skills, and the vast amount of software available for it, not only for prototypes, but for professional applications where extreme reliability, ruggedness and compliance with CE directives for EMC, Electrical Safety and RoHS are required.

iono is available in three versions, all using the same shield board and case, with different choices on the pre-installed Arduino board:

  • iono ethernet has an Arduino Ethernet board
  • iono uno uses an Arduino Uno board
  • iono solo comes without any Arduino board, so you can use your preferred Arduino board, as far as it is fully compatible with the Arduino 1.0 pinout and fits the iono case.

iono ethernet and iono uno are compliant with the CE certification requirements for electromagnetic compatibility (2004/108/CE), electrical safety (2006/95/CE) as well as the RoHS directive for hazardous substances (2011/65/UE).

Please visit for more information, complete circuit diagram, design tips and open source libraries.

We would be please to hear feedback and suggestions from the Arduino Community.

Best, Ulde - Sfera Labs

Hi everyone! Just wanted to add that iono is accompanied by a set of libraries that helps exploiting iono's features.

You can find them on GitHub:

In the repository you'll find the base iono library which provides a set of functions to monitor and control iono's input and outputs. Moreover, we developed a UDP library to efficiently broadcast iono's updates and a Web library implementing a REST API and push notifications to integrate iono with other devices, apps and/or supervisor systems.

Among the examples you can find a nice Web application that allows you to monitor iono's inputs, control its outputs and configure its network settings.

Here are some screenshots from the wiki's page:

Let us know what you think and feel free to reuse our code for your own projects!

New release of our Arduino libraries available! Get them on GitHub:


I really like the concept and the enclosure and web app look cool.

I work with developing commercial controls, and I think the biggest pushback you will get is in using an actual Arduino board. The silly thing is, if you copy it and take Arduino off but use the same exact components, people would be fine with it.

I do think this has a place in one-offs and it would make a prototype look a lot better due to the professional-looking enclosure.

Just a suggestion, it may be worth it to print your own board and call it "Arduino-compatible"...then people could use it without the stigma that comes with using an Arduino in industrial settings. I've argued against the stigma before, and no one has a solid reason, but it is definitely there.

Anyway, great job and keep up the good work! I'll follow this project for sure.

thanks for your nice words, and the feedback about using Arduino boards rather than fully embedding Arduino compatibility in our own board.

We’ve been thinking a lot about this, and we keep debating the pros and cons internally. I’m more than happy to share our point of view here.

You’re right that some people could consider using an actual Arduino board a downside but, in our opinion, it should be just the opposite.

The quality of original Arduino boards (hold your breath for a second about the recent issues within Arduino and their factory) is actually very, very good. We tested Arduino Uno and Ethernet way beyond all relevant CE certification limits and we have been very pleased with the results.

Embedding an Arduino clone in our board would be beneficial in other areas, like smaller size and possibly lower cost, but will not necessarily improve the real quality and reliability of the product. And designing our product as a shield, adds the flexibility of using the same iono board with multiple Arduino boards.

For example, iono uno and iono ethernet are just the same board, and the only difference is the Arduino board itself and the enclosure’s faceplate.

Of course the real downside of using a separate Arduino is that we now depend on Arduino to deliver these boards with a consistent quality and no unanticipated design changes.

The issues between some of the Arduino founders and their historical manufacturing partner are indeed very relevant for our product, and may add weight to the side of embedding our own Arduino clone in future versions of iono, if not solved quickly. And if we have to change the source of the Arduino boards, we would have to rework the CE certification.

Bottom line, the pros of using original Arduino boards are flexibility and time to market when a new board becomes available (think Arduino Zero), while the benefits of embedding are smaller size, reduced mechanical complexity, slightly lower product cost, and being fully independent from Arduino as boards manufacturer.

The overall product quality is more in people's perception rather than actual fact, and indeed we’ve so far received opposite feedbacks, with some people appreciating our use of original boards, and others rising the same concerns you have stated in your comments.

Thanks once again for your feedback.