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FCC Testing For Open Hardware

What do small scale open hardware projects do about RF interference compliance testing? I’ve been looking into selling assembled versions of a few of my projects like the Backwoods Logger, to people without the time or skill to build their own. If I’m lucky, I might sell a few hundred such units, through a dedicated store web site, or just a page attached to the BMOW blog here. I would want to do this right, which means complying with any applicable certification requirements for consumer electronic devices. In the United Sates, that means FCC Part 15.

After searching for information about FCC requirements, it appears that anything operating at frequencies above 9 kHz requires FCC verification testing, which costs several thousand dollars. This is true for both intentional radiators (WiFi modules, Bluetooth, remote controls, etc)  and unintentional radiators whose emissions are accidental. By that rule, everything from an Arduino clone to a data logger to a robot control board requires FCC testing. You don’t actually need an FCC ID, but you do need to perform the testing and keep your certificate of compliance on file, should the FCC ever ask for it. And your product must include a phrase like “This product complies with FCC requirements for a Class B device.”

I looked for information about how the “major” hobby electronics vendors handled FCC testing, and found that this is a topic no one wants to talk about. It’s like a dark family secret. Discussion threads get responses like “we can’t legally comment on this” and are then locked. Reading between the lines, it seems that while FCC testing is required for virtually every electronic board and module, almost no one actually does it. But because the penalties for non-compliance are worse if you knowingly sell an untested electronic product, nobody is willing to admit that they didn’t perform the tests, or even discuss the subject at all. I’m not going to name any specific vendors, but if you have any circuit boards on your desk that contain a microcontroller or USB chip or other interesting gizmos, check to see if it was FCC tested.

Have you ever sold an electronic product that you designed yourself? Have you ever taken a product through FCC compliance testing? What was your experience? Leave your feedback in the comments.

Read 13 comments and join the conversation 

13 Comments so far

  1. Erik Petrich November 7th, 2011 12:07 am

    Disclaimer: I am not a lawyer and this is not legal advice.

    How you looked at section 15.103 of the FCC rules? It specifies a number of device types that are “subject only to the general conditions of operation in section 15.5 and 15.29 and are exempt from the specific technical standards and other requirements contained in this part.” I think the Backwoods Logger could qualify for this exemption (assuming the 32.768 kHz crystal is used directly and not with a high frequency PLL):

    (h) Digital devices in which both the highest frequency generated and the highest frequency used are less than 1.705 MHz and which do not operate from the AC power lines or contain provisions for operation while connected to the AC power lines. Digital devices that include, or make provision for the use of, battery eliminators, AC adaptors or battery chargers which permit operation while charging or that connect to the AC power lines indirectly, obtaining their power through another device which is connected to the AC power lines, do not fall under this exemption.

  2. Steve November 7th, 2011 7:06 am

    Good thought, but backwoods Logger runs from the 8 MHz internal RC oscillator of the AVR. The 32.768 kHz crystal is just for the real-time clock.

  3. @ndy November 18th, 2011 10:33 am

    Is the certification only required on “consumer” equipment?

    Aren’t there different rules for “development” stuff, stuff that’s not sold for end users and for “industrial” equipment?

    This is something I’ve been pondering myself and have met a similar brick wall to you.

  4. Steve Chamberlin November 18th, 2011 7:38 pm

    If you’re just developing stuff for your own use then it doesn’t matter. But as soon as you start selling things to the general public, you have to follow the rules for a Class B device.

    Check out subpart B, unintentional radiators:

  5. JustAHobbyist June 14th, 2012 7:02 pm

    Man, you have got to be the only person I’ve seen that actually brought this up. I saw the Adafruit thread on it where they punted to an unrelated thread at Arduino (which is FCC stamped) and then locked the thread. Meanwhile I’ve been looking around at all the usual suspects’ sites… virtually nothing has an FCC mark.

    And I sincerely doubt that most of these little kits, arduino clones, etc that run on PIC’s and AVR’s have been tested, considering it can cost $10-20,000 to do so, per product (or so I’ve read).

    I get the sense it’s a giant Sword of Damocles hanging over the increasingly popular “maker”/DIY/hobby electronics community… and I’d REALLY rather someone talked about it, if only to petition the FCC for more realistic legal accommodation for small shops with small product runs.

    It almost makes me mad that nobody will discuss it openly so we at least know what’s going on. Good for you, bringing it up.

  6. Steve Chamberlin June 14th, 2012 7:36 pm

    Yeah, it’s weird. I’ve looked at this some more, and nobody but big corporations does the legally-required FCC testing. Nobody. A friend used to work at a large tech company, and was involved with the purchase if many smaller electronics companies. She said none of the acquired companies had done any FCC testing, even though they had a few million dollars in annual sales of electronics products. So the first thing she had to do after acquiring these companies was to put their products through the FCC tests.

    I think it’s like driving 70 in a 65 zone. You’re breaking the law, but nobody’s going to enforce the law in that case.

  7. Quora October 5th, 2012 12:27 pm

    How could FCC rules be changed to make it easier for small businesses to participate in the “Internet of Things”?…

    With the introduction of low energy Bluetooth technology, we are about to see a huge number of new business opportunities associated with smart devices. Because Bluetooth devices are “intentional radiators”, they require FCC certification as class B …

  8. LoC November 16th, 2012 8:25 am

    I am developing a product that requires FCC approval and I agree that not much information is available to help small business and DIY’s get started with compliance testing. The most difficult issue that I have run into is the ability to pre-test my device. I cannot afford to spend thousands of dollars to buy equipment to see how far off I am from passing or failing. There is the ability of renting equipment but you are still looking at easily a grand to rent and not to mention calibration and learning curve associated with the equipment. It does seem as though if you are developing something that is most likely not going to cause any interference than you can get away without FCC testing, but if you develop something that is going to be competitive in the current market your competition may try to slow you down by reporting you if you don’t have the testing done.

    The FCC is of course if you only want to market your product in the United States. IC is for Canada, which as far as I have found out is some extra paper work beyond FCC testing. CE for Europe is another beast. There seems to be a lot more information for CE and the ability to self-certify, which I am learning more about each day. The people associated with CE seem to have developers best interests at hand because they do provide more guidance as opposed to FCC. CE also requires testing on EMI/ESD in order to show that your device does not fail if it gets zapped by static.

    From talking with some people that have experience with FCC/CE/IC leaves me with the impression that most of these regulations are rarely if ever enforced, but are in place just in case your product starts dropping airplanes out of the sky.

    I have received a few quotes from different companies and they have all been around $15k for FCC/IC/CE testing. This seems to be the going rate if you don’t know what your doing. After receiving some useful advice we have managed to drop this price down to approximately $5k for FCC/IC testing and we plan to self-certify CE. I imagine that these prices will fall as more and more DIY’s come to market and more information is revealed.

    Just some insight from my experience so far.

  9. dino January 10th, 2013 9:03 pm

    Yea, I am a small hobbyist trying to commercialize a small project. I want to incorporate some sort of wireless and I am debating between the nordic nrf24l01+ and the rfm12b. I hear that the rfm12b module is fcc compliant but I am not sure what that actually means or does in terms of reducing my costs for fcc approval. I wish there was an easier way for hobbyists to get to market without going under the law and possibly getting caught.

  10. tharmy June 24th, 2013 3:29 am

    I work with getting products approved, and have had many different thoughts pass my way. One being – no one expects a small manufacturer to test in the same way as HP or a large OEM would be expected to.. the ‘spirit of the EMC regulations being mentioned. So – get a wide band communications receiver and spin through all the frequencies … if you can hear your device much further than 3m away ( using a small antenna ) then you ‘may need to investigate further’. If not – you have at least done ‘something’. ‘Due Diligence’ is always mentioned – but then so has ‘ it’s down to the courts to decide’ is a gotcha.

    For unintentional radiators – ( no uncertified radio gear ), then for £500 ( fact in UK ) you can go to an approved test house which has an anechoic chamber and get a mornings worth of testing. Enough to measure about 3 products properly.

    You do not need their test report – just the plots from the receiver – you have then done more than enough.

    However – I agree there is no real clarity for small batches or trial runs. In essence, they should all comply.

    I’m fortunate to have a ‘back garden’ test setup. Happy to help advise in UK.

  11. lotusmoon June 28th, 2013 3:46 am

    I am in the UK AND making a LED cluster strobe with variable frequencies ranging from 2.5Hz – 1000Hz . It will have a ready made and tested 240v ac to 4.5v dc power supply. would there be need to have this test I am looking to sell a few may be 10 – 20

  12. Jared July 21st, 2014 8:53 pm

    This topic is a bit… old, but I’ve occasionally run across some relevant info, so I’ll post it. For the FCC at least, one of the bigger “sources of violators” is HAM radio operators picking up interference, and issuing an actual complaint. Since a decent number of these guys also provide emergency (as in disaster-relief communications, such as after hurricanes) communications, their complaints do tend to get some attention. After that supposedly comes consumer applications: commercial & industrial applications are apparently expected to be less fussy, so they have slightly lower noise rules. Consumers, on the other hand, are expected to REALLY complain if your product screws up their game console, and if they’re the ones using the device, they’ll tend to notice pretty quick.

    As for testing, for anything self-certified, I’d first look at HAMs: if you can find someone with actual experience with RF emissions, then they should be able to help you out, especially if you pay them for their help. If you have too much noise, then building a proper metal enclosure is probably your best (a.k.a. fastest & easiest) solution: the AT/ATX, BTX, etc. standards have case specifications for this precise reason. Also, try to control the spectrums you emit on: nobody cares if you emit a trivial amount of noise on the same frequency as your local induction smelter, but if you interfere with satellite TV or AM/FM radio in any way that can be noticed, then it WILL be noticed. If you’re having trouble & a case doesn’t fix it, go looking for radio equipment and transmission line design info.

    Mostly though, build a case & get a HAM to check your emission:, as long as you aren’t intentionally emitting that should enable you to get low-thousand-dollar certification for non-residential products on the very first try. For COMPONENTS you might not even need certification in the first place (my Arduino Micro has certification, but a Raspberry Pi Compute Module might not even require it, since I don’t think those are stand-alone: worth checking into).

    Incidentally, if you can, then avoid the most stringent tests. One of the testing facilities is here in the OKC area, and last I heard it was in a class that only included ~ 3 other sites in the entire country: “more common facility” is likely to == “cheaper tests”.

  13. Scott September 28th, 2015 9:56 am

    I’ve been thru FCC several time for small and large companies. Short answer, if you have a digital device you must a FCC number from an approved FCC lab. Failure to do so can be $10k/day/device plus a year in jail if the FCC decides you did it intentionally. As far as budget, dead minimum without an intentional radiator (radio) would be $2k for lab fees if everything is perfect when you walk in the door and typically $5k. If you are using a radio without a pre-certified module add at least $5k. If you need a radio, a pre-certified radio module only get you out of the harder intentional testing, but you still have to do the usual testing. You basically pay per hour of booked lab time and most labs will not provide much guidance on how to fix problems. As someone above suggested, find a ham and pretest your device so that you can get in and out of the lab the first time.

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