Building and Certifying an Open-Source IoT Controller, Part 4: Regulatory Compliance

January 03, 2024 by Ignacio de Mendizábal

In the final installment of our series on the development of the Anthilla Controller, we look at the legal requirements for bringing the project to market in the European Union.

When we left off in the previous article, the Anthilla Controller (AnthC) was a functional prototype. That doesn’t mean the project is complete, however—the AnthC must meet its intended market’s regulatory requirements before it can be sold.

Because the company that initiated the project is located in Italy, the target market is the European Union (EU). This article, the last of the Anthilla Controller series, outlines the relevant directives and the process of compliance.


The CE Label

Before it can be sold in the European market, any product for which EU regulations exist needs to be labeled with the Conformité Européenne (CE) marking shown in Figure 1. This label is a declaration that the product meets all legal requirements related to safety, health, and environmental protection.


The CE mark.

Figure 1. The CE marking. Image used courtesy of the European Commission


The first step toward obtaining the CE marking is to identify what regulations apply to the product. For electronics such as the Anthilla Controller, the parameters to consider are:

  • Power: The AnthC is DC-powered, with a maximum voltage of 28 V.
  • Communications: The AnthC has WiFi and Bluetooth capabilities.
  • Batteries: The AnthC uses a coin cell for the RTC and a rechargeable LiPo battery as backup.

These features mean that we must consider directives around voltage levels, electromagnetic emissions, wireless communication, and electronic waste. We’ll discuss each of these over the course of the article.


Radio Equipment Directive (RED)

Identifying which requirements apply to a project can be difficult, especially if it’s your first time through the process. In the case of the Radio Equipment Directive (RED), however, it’s very straightforward. If your system is capable of any kind of wireless communication—Bluetooth or WiFi, for example—it falls under the directive.

The RED defines the requirements for placing radio equipment on the market. Among other things less relevant to today’s discussion, it covers:

  • Safety and health.
  • Electromagnetic compatibility (EMC).
  • The efficient use of radio spectrum.

The Anthilla Controller board includes an ESP32-S3 module, which is a microcontroller with WiFi and Bluetooth capabilities. It’s therefore subject to the RED.

Our first task is to check if the microcontroller has been already certified, which would make the process quicker and easier. Fortunately, the manufacturer has performed all the required tests and the certificate—reproduced in Figure 2—is available on their website.


RED certification report for the microcontroller used in the AnthC.

Figure 2. Certification report for the ESP32-S3-WROOM-1. Image used courtesy of Espressif Systems


We can see which standards were applied at the bottom of the certificate. We’ll go over each of the listed EMC standards in the next section.

Note that this doesn’t exempt us from performing tests of the board as a whole. Even though the module is certified, installing it in a new environment can change its emissions behavior. This can occur due to many factors—grounding, reflections, and amplification, to name a few. We’ve incorporated the module into a new system, and that new system needs to be tested and certified.


Electromagnetic Compatibility (EMC)

EMC regulations govern electromagnetic emissions. They require an electronic system to work without disturbing, or being disturbed by, other pieces of equipment in its vicinity. For the AnthC, the applicable EMC standards are:

  • EN 55032: Emission requirements for electromagnetic compatibility of multimedia equipment.
  • EN 55035: Immunity requirements for electromagnetic compatibility of multimedia equipment.
  • ETSI EN 301 489-1 V 2.2.3: Harmonized standard for electromagnetic compatibility—common technical requirements for radio equipment and services.
  • ETSI EN 301 489-17 V 3.2.4: Harmonized standard for electromagnetic compatibility—specific conditions for broadband data transmission systems.


Looking for information on the testing process itself? Check out “Understanding Electromagnetic Compatibility Tests,” a two-part technical article series covering both conducted and radiated EMC, on the All About Circuits website.


Low Voltage Directive (LVD)

The LVD is a safety directive that applies to equipment with input or output voltages in the following range:

  • Between 50 V and 1000 V of alternating current.
  • Between 75 V and 1500 V of direct current.

The Anthilla Controller is DC-powered, and has no input or output voltages higher than 75 V. The LVD therefore doesn’t apply. Instead, we’re subject to the EU requirements for general product safety. The actions we need to take on that front are outside the scope of this article, being mainly related to quality management.



Finally, we need to consider two directives unrelated to electrical or electromagnetic behaviors:

  • The Restriction of Hazardous Substances (ROHS) Directive.
  • The Waste from Electrical and Electronic Equipment (WEEE) Directive.

Together, these govern the proper management of electronic waste, which could otherwise pose risks to human health and the environment. Let’s take a look at ROHS first.


Restriction of Hazardous Substances (ROHS)

To prevent electronic waste from releasing hazardous substances into the environment, ROHS restricts what materials can be present in the electronics’ manufacture, and in what amounts. The directive governs usage of the following ten substances:

  1. Bis(2-ethylhexyl) phthalate, also known as di(2-ethylhexyl) phthalate or DEHP.
  2. Butyl benzyl phthalate (BBP).
  3. Cadmium.
  4. Dibutyl phthalate (DBP).
  5. Diisobutyl phthalate (DIBP).
  6. Hexavalent chromium.
  7. Lead.
  8. Mercury.
  9. Polybrominated biphenyls (PBB).
  10. Polybrominated diphenyl ethers (PBDE).

A product that’s ROHS compliant can’t have concentrations of these substances that exceed the ROHS-specified maximum.

In general, you don’t have to worry too much about this—component manufacturers already limit the amounts of these materials in their products. However, you should always verify what types of materials are used by your PCB manufacturer. Pay particular attention to these two areas where lead might show up in PCBs:

  • The soldering material. For ROHS compliance, you’ll need to mount components on the board using lead-free solder.
  • The PCB finish. Popular finishes such as Hot Air Solder Leveling (HASL) commonly have too much lead to be used in an ROHS-compliant product. You’ll need to use either a lead-free HASL finish or an entirely different finish, such as ENIG.


Waste from Electrical and Electronic Equipment (WEEE)

The purpose of the WEEE is to reduce the environmental impact of electronic waste and, when possible, prevent its creation. The directive requires manufacturers and distributors to take responsibility for the proper disposal and management of electronic waste resulting from their products. This responsibility lasts for a product’s entire lifecycle, even after it’s been sold.

In the Anthilla Controller’s case, the WEEE obligates us to:

  • Register the board in the countries where it will be sold. Since Anthilla is an Italian company, we started with Italy.
  • Track the number of boards placed on the market, and generate an annual report.
  • Add a WEEE label (Figure 3) to the board, and add information about proper disposal to the AnthC’s product manual.


The WEEE label.

Figure 3. The WEEE label. Image used courtesy of Your Europe


Wrapping Up

We’ve now briefly reviewed the legal requirements to sell an electronic device in the European market. As you can see, the amount of work related to non-technical tasks increases once a project leaves its prototyping phase. Selling an electronic product has benefits, but it also creates responsibilities.

With that, the Anthilla Controller series draws to a close. We’ve traced the project from idea to prototype, and then to the beginning of the mass-production phase. The process we followed can be easily extended to other kinds of products, as long as attention is paid to the peculiarities of each system.


Editorial note: The Anthilla Controller’s initial development, testing, and manufacturing was made possible by funding from Anthilla, but the company is not currently involved with the project. Neither All About Circuits nor the author of this article receive any financial benefit from Anthilla for the article’s publication.


Featured image used courtesy of github