I have designed a product that is essentially a USB HID device for a computer game. It consists of several on off switches and 5v servos run by an atmega2560, all sealed and enclosed in a plastic case. From everything I have read I believe it might be exempt from needing certification, but I would greatly appreciate a second opinion; I'm simply a hobbyist trying to decide the feasability of taking this product to market.


  • \$\begingroup\$ Sorry. It's for the EU market. I have read through the directives and from what I understand I think my product would be exempt: not operating at higher than 9khz, 5v, very low current, no AC power solely operated by USB. emcfastpass.com/… \$\endgroup\$ – Stags Mar 26 at 15:16
  • \$\begingroup\$ not operating at higher than 9khz An ATMega2560 typically runs at a clock frequency that is much higher than 9 kHz. I am not saying that therefore your device needs to be certified. \$\endgroup\$ – Bimpelrekkie Mar 26 at 15:24
  • \$\begingroup\$ @Stags, as far as I know there is no version of the USB standard that allows operation below 9 kHz. \$\endgroup\$ – The Photon Mar 26 at 15:27
  • \$\begingroup\$ You're right. A schoolboy error on my part, mixing up kHz and mHz. Thanks for your comment. \$\endgroup\$ – Stags Mar 26 at 15:28
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    \$\begingroup\$ 5v servos might be quite noisy too \$\endgroup\$ – Huisman Mar 26 at 15:31

For the European market you need to CE mark all electronics. In this case by providing a Declaration of Conformity (DoC) to the EMC Directive. And in case of 230VAC supply etc, also the LVD directive. The DoC in turn is a legally binding document where your company states that, yes, we follow these directive(s). You also need a physical CE mark on the product "if feasible".

The directives in turn point to standards that can be used to fulfil the directive, but that's another story.

You probably don't have to perform a 3rd party verification by a test house however. But in case your product happens to have poor EMC performance out in the field, you'll be in for some major trouble if you can't prove that you've taken all necessary precautions.

If an approved test house has said that your product is fine, then you have your back free in court. As in: we have tried our best to ensure that this product is compliant. But you can of course still be forced to withdraw the product from the market etc.


You should define which market.

For the European market, you have to affix CE marking to be allowed to sell it on the European market. And to affix CE marking you need to comply to (applicable) directives.


These directives lay down the essential requirements that products have to fulfil.

It is a common misconception you need to comply to standards/norms. It is not true:

The use of standards is voluntary - you are not obliged to use them. You can also opt for other technical solutions to fulfil the essential requirements set out in the relevant EU directive.


If harmonised European standards exist for your product and you follow them in the production process, your product will be presumed to be in conformity with the requirements laid down in the relevant EU directives.

you're going to have a very hard job to prove conformity without using standards/norms.

Source of quoted text

So, doing EMC testing using harmonised standards comes closest to the proof your product is satisfying the EMC directive.

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    \$\begingroup\$ More info on the "CE" logo in this EEVBlog video: youtube.com/watch?v=f0uvS80YIGU&t=4s \$\endgroup\$ – Bimpelrekkie Mar 26 at 15:20
  • \$\begingroup\$ The video is wrong saying CE is self-certifying for all products and no external testing is required (video time about 5:30). For some products, special conformity assessment bodies ('Notified Bodies') must verify that your product meets the specific technical requirements. (source link in my answer) \$\endgroup\$ – Huisman Mar 26 at 15:40

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