In the United States, the FCC is responsible for maintaining harmony among hundreds or thousands of businesses all trying to use the same resource: the electromagnetic spectrum. The upside of this is that we can (usually) rely on things like WiFi, cellular phones, police radios, baby monitors, etc etc to work as and when we need them to. The downside is that it creates a hurdle to those of us who want to do business within the United States selling electronics and electronic devices.

There are many myths, misconceptions, and misunderstandings regarding compliance with these laws. We've done a lot of work recently to try and unravel the rules and how they apply to SparkFun, and to other businesses as well. Here's a list of Frequently Asked Questions that may help people understand better what the FCC rules mean (and don't mean) to their business or hobby.

What does the FCC have to do with electronics?

The Federal Communications Commission (FCC) was established by the Communications Act of 1934. Their role as regards to electronics is to safeguard the radio spectrum within the United States and its associated holdings. This is achieved by dividing up the radio spectrum into ranges and assigning each range to a different application, and it is achieved by requiring persons or entities wishing to operate within those ranges to seek various forms of licensure or authorization to do so.

More simply, the FCC seeks to manage a valuable and common resource (the radio spectrum) by functioning as a central clearinghouse for who’s doing what, where. Any electronic device has the potential to interact with that resource, and the FCC has rules regarding which devices must meet which limitations to be legally sold and used within the United States.

What does this mean for a hobbyist?

What does this mean for a small manufacturer of open source hardware?

Potentially, a lot, depending on what you’re doing. There are exemptions, but not many. Ultimately, if you are an importer or seller of electronic goods in the US, there are laws regarding FCC compliance that you need to be aware of and adhere to. In almost all cases, devices being manufactured by small OSHW companies are subject to the guidelines set forth in Part 15 of Title 47 CFR

Even devices which do not use radio transmitters?

Yes, because in the right (or wrong) circumstances, any device which contains a relatively high speed clock (above the low kHz range) stands to possibly produce unwanted interference to other local devices. Devices which do not use radio transmitters are referred to as “unintentional radiators” , and the testing bar is lower for them than it is for intentional radiators. Thus, all devices which cannot be exempted must obtain FCC authorization prior to being marketed in the US.

What can I do to avoid expensive testing and still remain in compliance with the laws?

There are two ways to avoid testing: restrict yourself to selling only subassemblies, or restrict yourself to devices on the exempted products list. The exempted product categories are pretty hard to remain within, and are given in section 15.103 of CFR47

A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft.

A digital device used exclusively as an electronic control or power system utilized by a public utility or in an industrial plant. The term public utility includes equipment only to the extent that it is in a dedicated building or large room owned or leased by the utility and does not extend to equipment installed in a subscriber’s facility.

A digital device used exclusively as industrial, commercial, or medical test equipment.

A digital device utilized exclusively in an appliance, e.g., microwave oven, dishwasher, clothes dryer, air conditioner (central or window), etc.

Specialized medical digital devices (generally used at the direction of or under the supervision of a licensed health care practitioner) whether used in a patient’s home or a health care facility. Non-specialized medical devices, i.e., devices marketed through retail channels for use by the general public, are not exempted. This exemption also does not apply to digital devices used for record keeping or any purpose not directly connected with medical treatment.

Digital devices that have a power consumption not exceeding 6 nW.

Joystick controllers or similar devices, such as a mouse, used with digital devices but which contain only non-digital circuitry or a simple circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital conversion) are viewed as passive add-on devices, not themselves directly subject to the technical standards or the equipment authorization requirements.

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. Responsible parties should note that equipment containing more than one device is not exempt from the technical standards in this part unless all of the devices in the equipment meet the criteria for exemption. If only one of the included devices qualifies for exemption, the remainder of the equipment must comply with any applicable regulations. If a device performs more than one function and all of those functions do not meet the criteria for exemption, the device does not qualify for inclusion under the exemptions.

Tell me more about subassemblies.

The more easily accessed method for avoiding testing is to stay within the definition of a “subassembly”. Subassemblies are defined in section 15.101e of Title 47

Subassemblies to digital devices are not subject to the technical standards in this part unless they are marketed as part of a system in which case the resulting system must comply with the applicable regulations. Subassemblies include: Devices that are enclosed solely within the enclosure housing the digital device, except for: power supplies used in personal computers; devices included under the definition of a peripheral device in §15.3(r); and personal computer CPU boards, as defined in §15.3(bb); CPU boards, as defined in §15.3(bb), other than those used in personal computers, that are marketed without an enclosure or power supply; and Switching power supplies that are separately marketed and are solely for use internal to a device other than a personal computer.

CPU boards are defined in section 15.3(bb):

CPU board. A circuit board that contains a microprocessor, or frequency determining circuitry for the microprocessor, the primary function of which is to execute user-provided programming, but not including: A circuit board that contains only a microprocessor intended to operate under the primary control or instruction of a microprocessor external to such a circuit board; or A circuit board that is a dedicated controller for a storage or input/output device.

So, basically, if you can stay within these guidelines, then testing is on the shoulders of the person or entity integrating your device into their final product. Of course, in the case of a hobbyist, that means they don't need to do anything but abide by good engineering practice and cease operation if interference occurs.

What about kits?

Kits are defined in section 15.3(p):

Kit. Any number of electronic parts, usually provided with a schematic diagram or printed circuit board, which, when assembled in accordance with instructions, results in a device subject to the regulations in this part, even if additional parts of any type are required to complete assembly.

We will seek clarification on this point and update this document in the future, when such clarification is available, but at this time, SparkFun will not be doing FCC testing on kits.

Are “development tools” exempt from the rules?

No. There are no exemptions in the rules which specifically apply to development tools. Furthermore, devices which can be purchased by the general public must adhere to the more rigid “Class B” emissions limits, rather than the more relaxed “Class A” industrial limits.

How much does it cost to obtain authorization under the FCC rules?

That depends on your device. Devices which require Verification or a Declaration of Conformity- which is to say, unintentional radiators- can be tested for about $1000. There is usually an additional fee of around $500 for a report which may or may not be needed. For intentional radiators, the Certification cost is more like $10,000-$12,000, unless an approved module is used. It may be that you will fail, of course, which will require retesting.

Some transmitters come with an FCC ID on them. Does using these devices exempt me from further testing to achieve FCC authorization?

Not entirely. While it does lower the bar from the costly Certification process, you are still responsible for ensuring that your product does not emit other radio frequencies. In short, you must test it as though it were an unintentional radiator.

What are the labeling guidelines for devices which have FCC authorization?

Sections 2.925 and 15.19 deal with the labeling requirements. Alternatively, OET KnowledgeBase article 784748 deals with the requirements for labeling devices to meet FCC guidelines. One thing not mentioned is the implication of including a certified module in your product- in that case, either the FCC ID of the module must be visible or there must be a label on the outside of the product stating “Contains FCC ID: xxx-yyyyyy”.

Failure to properly label a device is probably one of the highest risk points in the entire system. If an Enforcement Bureau agent sees a device which, in their estimation, should be labeled, that device is far more likely to be called into question.

Where can I go for more information?