Regulatory compliance for the 3DR Radios

There has been a lot of discussion about regulatory compliance on the announcement thread for these radios.

I thought I should explain a bit about why these radios don't already have compliance certificates, and what you can do to get involved in an effort to get them certified. I should first note that I don't work for 3DRobotics - I'm just a volunteer ArduPilot developer who happens to be very interested in these radios. I also wrote most of the radio firmware. So this is not an official 3DRobotics statement.

The basic idea with regards to regulatory compliance is that these are DIY radio parts. It is our understanding that, at least in the US and Australia, it is quite OK to use radios that comply with the relevant standards without getting them officially certified. Other countries have different rules.

So why didn't 3DRobotics get them certified anyway? Part of the problem is that the firmware is being rapidly developed, with new features regularly added. Under some certification systems that may mean re-certifying each firmware. That would cost a lot, and push up the cost of the radios.

The second problem is that there are so many different certification systems. There is FCC in the US, C-Tick in Australia, CE in Europe etc etc. Sometimes it may be possible to get quicker/cheaper certification of one type if you already have another type, but it is still complex.

So what do you do if you want to use/distribute these radios in a way that requires certification? I think the only reasonable answer is for the community to solve the problem. If someone puts their hand up to volunteer to do the legwork to get these radios certified in some area then they could share the results here and hopefully make life easier for someone else to work on certification elsewhere.

Meanwhile, if you post something about certification, please try to make sure you do your research carefully to make sure the information is accurate. If we can build a community effort around this then I think we can solve it together.

Cheers, Tridge

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  • Just a further thought - if you could get all the documentation from 3DR icluding the submission and results from the FCC then that should be sufficient to self certify without having to do the testing here as 3DR will already have done it.

    As long as you have acted in good faith there is unlikely to be any action taken. Anyone holding the appropriate Amatuer Radio Licence could operate them without a CE marking.

  • OK, lets start with the regs for Self Certification which can be found here.

    Now it may look complicated but when you study it it is quite simple. The 3DR radios work on 5 volts or 12volts and are battery powered. That immediately takes them out of -

    Low Voltage Directive (2006/95/EC)

    Article 1 states the Directive covers "any equipment designed for use with a voltage rating of between 50 and 1000 V for A.C. and between 75 and 1500 V for D.C, other than the equipment and phenomena listed in Annex II."

    The 2 to comply with are (1) Electromagnetic compatibility and possibly (2) Radio and telecommunications terminal equipment. I would have to check further but I think they our outside of the scope for No. 2.

     So I believe all it needs is the Electromagnetic compatibility, and I have explained how this can be achieved. We used a room for our tests but because these radios are so small then a small metal box would suffice with a small opening for the

     spectrum analyser probe. You then compile a file as outlined in the article which is kept at the business address. Give the file a reference number and enclose a slip with the product stating it has been tested and include the reference number and the name and address of the supplier.

    OK there is a bit of work but nothing difficult.

    I would guess you can hire a Spectrum Analyser for about £200 pw.

    It is something I ould do but unfortunately not at the present time, but I would help with advice.

  • .

    When the CE regulations came into force which I think was 1999, I ran my business making one off specialised computer systems. These regulations gave us a dilemma in that it was impossible to pay the £10k that laboratories were asking for a CE certificate.

    I obtained a copy of the CE regulations and found a section on “Self Certification” which allows you to make equipment and certify it yourself.

    All the parts we bought were already CE marked, but when you put them together you create a new product but you start from a good point. We then built a small room lined with metal mesh so no interference could enter. So all you need now is a Spectrum Analyzer to measure 0 – 50GHz. Now these are very expensive but you can hire them by the week and you only need to test your first production model.

    Providing you have no stray signals you write how you have tested the equipment. Receivers should not cause much problem. With transmitters you should only get the Tx frequency and its harmonics.

    Now attach a CE sticker. No one ever questioned our systems.

    I am sure that some of the dealers in the UK could import the radios and carry out the above.

  • I got hold of some 433 modules now and look forward to testing them.

    Having a (recently acquired) ham-license allowing me to transmit in the 430MHz band at power levels enough to cook chicken (500watts), I see no problem in using them other than the general requirement to transmit your call sign at the beginning, end and at regular intervals in any transaction. 

    You have the LBT and other necessary features all lined up but not the call sign from what I can find. I wonder if the callsign can be included in some way in the packets so that I can honestly say to my critical ham buddies that I fulfill all my obligations when using these things.

    Would that be something to add in the future??

    73 de TF3BGL

  • Has anyone found out any information regarding the 3dr in Canada.  I am looking at ordering, but my Canadian dealer won't sell them.  Is it just because they don't have a government stamp on them?  I am having a hard time finding much information on the regulatory side of this.  From what I can tell, the 900 version is still running on the ISM band.  And as far as certification goes what is the difference between this and some of the cheap vTx guys are using, some putting out 1.5 watts?Sorry for the questions, this one has got me confused.

  •    The FCC rules are almost completely unintelligible, and will certainly give you a headache unless you have some special form of retardation that allows you to think they were written by normal human beings.

       I found an interesting link summarizing the rules though.  This is from Ti, who makes the main competitor to the SiLabs chip radio we use.  It's a little easier to read, although most measurements are still given in retard units.

       It also covers the European rules. 


    ISM-Band and Short Range Device Regulatory Compliance Overview
  • Someone might want to look into this section of the FCC rules.  Perhaps a "Declaration of Conformity" is all that is needed.  Sure sounds a lot easier to stamp "This device complies with Part 18 of the FCC Rules." on each radio rather than try to have them certified.

    Edit: Looks like maybe this only applies to receivers. Still worth looking at though, I didn't have the time to ready thoroughly.  


    Sec. 18.212 Compliance information.

    (a) Equipment authorized under the Declaration of Conformity
    procedure shall include the following compliance information in lieu of
    the information required by Sec. 2.1077.
    (1) Identification of the product, e.g., name and model number.
    (2) A statement similar to the following:

    This device complies with Part 18 of the FCC Rules.

    (3) The name and address of the responsible party as defined in
    Sec. 2.909 of the rules. This party must be located within the United
    (b) The compliance information may be placed in the instruction
    manual, on a separate sheet, or on the packaging. There is no specific
    format for this information.

  •    To get this radio certified all we really need to do is get the module certified.  That's HopeRF's job, but they're a Chinese electronics factory and might not have that much interest unfortunately.

       So the only real thing to do is contact HopeRF and try to work something out with them.  They may be interested in certifying it or at least splitting the costs somehow.  They may also have the equipment to perform the tests, in which case it should be fairly cheap just to file the paperwork.

       The FCC likes independent labs to perform the tests, but if you do them yourself they just want a lot more paperwork on how the tests were performed, and it will probably take longer.

       The other possibility is that someone else has already certified the module.  HopeRF would probably know about that, or at least know who their large customers are.  Any of their customers in the US have most likely certified their product.  In that case we would just need a letter of authority to use their FCC number on our radios.  They may want some consideration in exchange, or details and guarantees about how the radios are constructed, but that would be the easiest way to go.

       If nobody has done anything then the best bet is working with HopeRF and/or their customers to get the damn thing certified and splitting the costs.  I'm amazed that HopeRF has not already done this, but the unit is fairly new and they're probably already working on it.  It would be silly to have everyone using the module each paying for certification.  The FCC already gets enough money from mega-corporations by selling OUR spectrum to them at a price only mega-corps can afford.

  • I don't understand why we would be certifying somebody else's radio module.  That's their job, and the only real reason to use a module in the first place.

  • Moderator

    It's been very educational (and somewhat depressing!!) watching Jim Drew of XPS go through the certification process on their new radio.  Basically you have to have a lab run the certification tests for the radio unit and have the results submitted to the FCC to get a certification number.

    Judging by XPS's experience it can be a slow and expensive process!

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