SparkFun Forums

[wjb21]

Is the RF-MiRF module FCC approved? My understanding is that even if the device is low power and in an unlicensed band it still needs to go through part 15 and 17 FCC approval. I would love to be corrected...

Regards,

Will

[sparky]

Hi Will,

http://www.access.gpo.gov/nara/cfr/wais ... 15_04.html

Part 15.19, labeling requirements:

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

So an RF guru (or an FCC inspector) is going to have step in here. As long as the device has this labeling on it, you do not need any kind of FCC licensing. Of course the MiRF can take incoming interference, the nRF2401A takes care of that. The MiRF should not cause interference with other devices. At 1mW max output power, the MiRF can interfere with very little. The FCC is not likely to come beating down the door of anyone for 1mW interference. We wouldn't be having this conversation if you were thinking of producing 100,000 units, so you should read this chapter as well:

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.

-Nathan

[wjb21]

Hi Nathan,

Part 15.19, labeling requirements:

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

So are you saying that if you have good reason to beleive the device is compliant (e.g. because you are using the nRF2401) you can self-certify and just stick that text on it? I know this can be the case for CE marking in the EU, but I though the FCC was more strict. Many thanks.

Will

[sparky]

That's correct. The nRF2401A is a low power device operating in the unlicensed band.

-Nathan

[wiml]

My understanding is that section 15.247 is the one that applies to these things (intentional radiator, digitally modulated but not frequency-hopping, 902-928 MHz band).

[bill951]

Is the RF-MiRF module FCC approved? My understanding is that even if the device is low power and in an unlicensed band it still needs to go through part 15 and 17 FCC approval. I would love to be corrected...

Regards,

Will

Take a look at this document:

http://focus.ti.com/lit/an/swra048/swra048.pdf

At 1 milliwatt, there is no way (other than perhaps with a very high gain
directional antenna) to exceed the field strength levels that would
cause a problem getting certified without frequency hopping (with frequency hopping much stronger signals are allowed). So, if
you went to an FCC-approved lab to have it certified it would be certain
to pass. It is my understanding of the law (and I could be wrong - I'm no
lawyer) that if you are selling commercial products then you need to
do the certification (which is a several thousand dollar expense). It
seems to me that should not be necessary if, from fundamental calculations, you can show that the signal levels are going to be
acceptable. But, the world is rarely the way I think it should be.

[wjb21]

That is my interpretation also - even though it is guaranteed to pass, you still have to have FCC certification if you are making more than 5 for home use. As an intentional radiator, you also have to chek up to the 10th Harmonic! which makes for an expensive lab. I don't think this is necessary in the EU as you can self-certify if you have good evidence that it meets the spec.

[bill951]

That is my interpretation also - even though it is guaranteed to pass, you still have to have FCC certification if you are making more than 5 for home use. As an intentional radiator, you also have to chek up to the 10th Harmonic! which makes for an expensive lab. I don't think this is necessary in the EU as you can self-certify if you have good evidence that it meets the spec.

Paragraph 2.5 summarizes it: "If a vendor or manufacturer wants to bring an unlicensed wireless transmitter to the US market, they must have the transmitter tested in a laboratory that is authorized by the FCC. After successful completion of testing, the manufacturer applies to the FCC for certification. If the test results are compliant with the regulations of FCC part 15, the FCC will certify the transmitter and issue an FCC identification number for the product. The vendor then must attach a label to each transmitter that contains this FCC identification number.

I have a Logitech cordless mouse which I think uses the nRF2401. It has FCC ID: DZL201705 stamped on it.