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
Replies to This Discussion
-
Permalink Reply by Grips on -
Good idea to split the topic Andrew. I am going to look into the certification process for Canada. I referenced all of the issues with this in the similar document.
I asked in the other thread but is it just the Si4432 that actually emits the radio data or is it the HM-TRP? I'm trying to figure out if I need more info on the HM-TRP or not. There seems to be plenty on the Si4432.
-
DeveloperPermalink Reply by Andrew Tridgell on -
Grips,
The radio module itself is a Si4432, but all of the control of frequency, modulation etc is the job of the Si1000. They come as a package, so I normally don't think of them separately.
Then Hope packages the lot as HM-TRP-433 and HM-TRP-915 boards, which 3dRobotics then puts on a carrier board so you can connect to it via FTDI or USB.
Cheers, Tridge
-
Permalink Reply by Helldesk on -
So there is a fair change that these modules are already known and certified in some other product somewhere, I take it? If nothing else, that would be encouraging for the eventual certification process in the sense that it should be able to pass as far as its hardware design goes. Now, the tricky part is whether or not and when does a new software revision make it a whole new product...
-
DistributorPermalink Reply by Martint BuildYourOwnDrone.co.uk on -
Hi Tridge,
I think this thread is a great Idea :)
I have already started down the road here in the UK and EU on working towards finding out what is needed, I will be happy to share any and all information found while I look into this, I know from chats I have had here with Ofcom before it can be a long road :( However I would love to hear from others here in the UK that would like to help get to the bottom of this, and I hope we will have a positive result!
Like Grips / Helldesk, I'm working down the line of the parts used in the system have some form of approval which can then be used here.... :)
Could I ask for a very clear outline of the parts that do the "Radio" part.. I see Grips has asked for the information here and over in the other Radio thread. This will allow me to move this forward as quick as I can! :)
I see there is no information on the product page in the store about these issues we are working towards right now, should there not be an update on the product page to say that these "might not be legal" until we tie this down?
Regards
Martin
-
DeveloperPermalink Reply by Andrew Tridgell on -
Hi Martin,
Thanks for looking into this!
As I mentioned to Grips, its a Si1000 with a Si4432 radio module (the Si1000 also supports using a Si4430 or Si4431, but those are lower power level than the Si4432 in these radios). When you buy these modules from Si or Hope you choose what frequency range you want the radio module to support.
There is also a FTDI chip for interfacing it to the USB, but that isn't really all that significant, although I guess it could affect unwanted radiation in a small way.
The Si1000 itself does all of the management of the frequencies, power levels etc, then the Si4432 puts it onto the antenna. If you want to, you can actually run the Si1000 at any frequency from 245 up to 954 MHz, and you will get some power out, just not very much as the Si4432 is setup for a particular band.
So for example, I've successfully made a 3DR 433 radio talk to a 3DR 900 radio by forcing the frequencies to match, but the range is terrible :-)
When 3DRobotics make the radios they load a bootloader that is specifc to the frequency band of the Si4432 on the radio. That bootloader has a magic byte that says what band the radio is. The main firmware looks at that byte to see what frequency range it should allow the user to setup in the EEPROM parameters.
Does that explain things enough? I'm not sure what level of detail you'd like.
Cheers, Tridge
PS: I'm a software engineer, not an electrical engineer, so apologies for any poor information
-
DistributorPermalink Reply by Martint BuildYourOwnDrone.co.uk on -
Tridge,
I'm not either a software engineer or electrical engineer, I just have a real passion for this stuff and do what I can with the limited experience I have, I have picked up all that I know from these pages here at DIYD over the past few years, and while I don't post as much as I once did I still keep a hand in by reading all I can!
I think that this information is more than enough to be getting on with for now, I'm a little disappointed that there is not more involvement from the other store owners looking to get to the bottom of this issue with me, however I'm sure that "we" (the community) will get to place where we will know either way in the coming days!
I have started to dig into the ETSI rules right now, as I understand this might be a good route to take from some other reading I have had been doing while looking at the 868 Xbees a while back and some other possible telemetry options for us here in the UK... :)
Regards
Martin.
-
Permalink Reply by Veikko Vierola on -
Could the certification process be easier if the radios were equipped with certified high/low pass filters to ensure that the radio will not go out of its designed frequency even if the boot loader or the eeprom setup was set to tx on different frequency?
-
Permalink Reply by Richard on
-
It makes no difference, the devices can be tested with "stock firmware settings".
If a user then changes those settings outside of those, the user is the one who (may) be breaking the law.
- As an example, almost all WiFi routers have easily-accessible settings that are illegal to use in some of the regions where they are sold.
-
ModeratorPermalink Reply by Mark Harrison on -
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!
-
Permalink Reply by Jake Stew on -
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.
-
DeveloperPermalink Reply by Andrew Tridgell on -
Jake,
3DRobotics isn't just "somebody else". They work closely with the ArduPilot dev team to develop hardware that matches the needs of APM users.
In this case they have developed a great little radio, but they didn't do the software for it, we did. The certification process is just as much about the software as the hardware, so its quite appropriate that the community works on certification if that is wanted.
If we'd just waited for 'somebody else' to develop a radio like this then in all likelyhood it wouldn't have happened.
Cheers, Tridge
-
Permalink Reply by Jake Stew on
-
Maybe I wasn't clear. HopeRF makes the radio module. It is HopeRF's job to certify that radio module.
That is the main advantage to using a radio module built by somebody else rather than doing your own design.
If you want to make a radio enabled device you either have to pay around $10k to get it tested and certified or you use a radio module that is already certified.
If you're producing 100k+ units then it is cheaper to certify your own design. If you're producing 1,000 units then it is probably cheaper to pay the extra money for a module and let the module manufacturer spread the certification costs among all the many different users and applications for that module design.
HopeRF can't expect EVERY single user of their module to kick down the cash to get THEIR design certified in the end application. That would defeat the purpose of using a module!
Social Networking
Top Content
Contests
Season Two of the Trust Time Trial (T3) Contest has now begun. The fourth round is an accuracy round for multicopters, which requires contestants to fly a cube. The deadline is April 14th.A list of all T3 contests is here.
Groups
-
ArduCopter User Group
1283 members
-
Moderators
24 members
-
ArduCopter (traditional …
180 members
-
Queensland
4 members
-
Turkish Ardu Group
5 members
Advertisement
© 2013 Created by Chris Anderson.
Powered by
