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Test and measurement supersedes intentional emission. If it were the other way no development boards would get sold, especially necessary things like low volume engineering samples. Should a one-off need certification before it can be transferred to the company that contracted the work to build it? No.

If you have never sought certification know that it is quite expensive.

What seems to matter the most is if anyone actually notices interference, and if they do how widely the device ended up being sold. If a test and measure product starts making it into everybody's house eyebrows will be raised.

If you misuse a test and measurement device and generate interference it is typically on you.

https://www.raspberrypi.org/documentation/hardware/raspberry...

> Test and measurement supersedes intentional emission.

On what authority are you claiming this? The language LeifCarrotson quoted refers only to digital devices, and the language I quoted above says plainly that a digital device must be an unintentional radiator.

To be clear, I believe selling their dev board is fine, but it's fine in the same way that driving 60 mph in a 55 zone is fine. Anyone selling an intentional radiator dev board that could reasonably be considered to be a complete device in itself is taking a small risk of FCC action, especially if (as here) they're pushing the limits of "dev board". Note that the Raspberry Pi developers do seem to get certs.

On what authority are you claiming otherwise?

My opinion comes from experience and getting things certified but also common sense and observing enforcement patterns (the latter of which is most important until they overstep and get challenged).

Go back to my example: Does a one-off product need to be certified to be transferred to the people that paid for it? Keep in mind, best case, this will add a roughly >$10k fixed cost to the sticker price.

It's a general principle in common law that the law makes sense. The popular, sophomoric, and extremely conservative interpretation of the FCC rules makes no sense by way of being extremely costly for no discernible benefit, either to the seller, the buyer, or the economy at large.

I am claiming this on the authority of the text of the regulations. The USA is a nation of laws, and those regulations have the power of law. If it came to that, a judge isn't going to disregard them just because you think they're too expensive. If you think otherwise, can you provide case law to support your view?

By law, that one-off intentional radiator absolutely does need to be certified. The FCC's enforcement priorities will be different depending whether that product is a little 2.4 GHz radio or a television transmitter, but their enforcement discretion doesn't change the law. Anyone who wants to be compliant needs to pay for the testing (or use a certified module, which is often easy and cheap; I've done that several times myself).

Lots of people disregard lots of laws because they're too expensive to comply with. Most of them get away with it, and a few of them get nasty surprises. I believe that I've given both the correct legal advice and a correct description of typical (not fully legal) practice. It's not helpful to conflate the two.

The text of the law matters not as much as what the law was intended to do. In any case, by saying the one off needs certified you've gone off into la-la land; any reasonable person classifies it as a test/measurement device and gets on with their life.

You are failing to distinguish between the law as it's written and the law as it's currently enforced, and inventing a quasi-legal framework with no relationship to actual American law to justify your conflation. It's true that judges will sometimes consider legislative intent when the text is unclear; but in this case, the text is perfectly clear, so that's not relevant.

Large companies, small companies that want to get bought by large companies, and other conservative entities generally aim to comply with the law as written, even though there's lots beyond that you can probably get away with. Everyone should judge for themselves how far they want to push from clearly legal actions to grey to clearly illegal but unenforced; but they should know which one they're doing, and your advice isn't helping.

If we submitted a KDB inquiry asking the FCC whether the board in question required certification, what do you think they'd say? (It's free, and you typically get a quite competent response within a few days. If anyone wants to try, please use a generic description, and not a link to the particular product. I doubt the FCC would waste their time enforcing, but the chance isn't zero and the developers don't need that attention.) Or why do you think the Pi developers got certs?

antoniuschan99 2107 days ago

If it’s sold as a kit(eg. Devboard) or battery powered it doesn’t need to be certified. You also can get pre-certified boards, the wroom-02 being the pre-certified esp8266.

I've seen certified development boards also, but what most don't realize is you can't combine certified parts to make a certified product. So depending on your product there is literally no benefit to getting it certified.

There are things that are battery powered that need to be certified and things that are not kits that don't need to be, though, so I'm not sure I can agree with that wording.

https://apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm...

I think battery-powered unintentional radiators can sometimes avoid testing, but battery-powered intentional radiators definitely don't. The statement about kits is also wrong, per pdabbadabba's comment below.

An intentional radiator module can get a module certification. In that case the final system still needs verification (the same kind of testing that an unintentional radiator gets), but doesn't need certification. When you see a label on the outer device that says "Contains FCC ID XXX-XXXX", that's the module's ID.

antoniuschan99 2107 days ago

Verification is Declaration of Conformity (DOC)? You can either get a Declaration of Conformity from the lab or just sign it yourself. But in the chance you get audited and it doesn't function how you said it would then you'd get in trouble

Verification and DoC are different (and apply to different types of unintentional radiators), but you're correct that neither involves filing anything with the FCC (or any private body accredited by the FCC; for real most certifications go through a TCB, not directly to the FCC). You just make the file (including any test results required) and keep it in a drawer. The FCC can come and ask for it, and if you don't have it then you're in trouble.

ETA: And here's the section about battery-operated digital devices (i.e., unintentional radiators, with no radio transmitter):

> § 15.103 Exempted devices.

> [...]

> (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.

And here's the section that makes it fine to build your own stuff in limited quantity, as long as you don't do anything obviously stupid:

> § 15.23 Home-built devices.

> (a) Equipment authorization is not required for devices that are not marketed, are not constructed from a kit, and are built in quantities of five or less for personal use.

> (b) It is recognized that the individual builder of home-built equipment may not possess the means to perform the measurements for determining compliance with the regulations. In this case, the builder is expected to employ good engineering practices to meet the specified technical standards to the greatest extent practicable. The provisions of §15.5 apply to this equipment.

tripletao 2105 days ago

And I'm responding again to note that I think I interpreted "kit" wrong. I was thinking "kit" as in § 15.23, which gives an exemption for stuff you build yourself but not stuff you build from kits.

But 47 CFR § 2.803 gives an exemption for "evaluation kits". I don't think that clearly covers boards used primarily as single-board computers (and not genuinely for evaluation), and I'd guess that's why the Pi developers got certs for their boards. I believe it's the best argument that this board wouldn't need certification (or verification), though.