Notices
Weatronic Support Forum Go here to get help with your Weatronic products.

Weatronic Telemetry Protocol API

Old 09-07-2014, 08:43 AM
  #1  
hcc23
Junior Member
Thread Starter
 
hcc23's Avatar
 
Join Date: Sep 2014
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default Weatronic Telemetry Protocol API

As this is my first post:
A big HELLO to the R/C Univerese in general and the Weatronics users in here in particular!

(If you don't care about my background skip the next sections and simply read my question at the bottom...)

I am looking forward to some hopefully productive exchange of ideas and information with all of you, especially since I am a total newbie to anything R/C flying and went in to this new hobby of mine with a little to much breadth and to little depth...
I started of wanting to scratch build a multicopter, paused that, switched to planes (as those--clearly--should be easier ), elected to start an autonomous conversion of a Guilllows C172 (mind you I have never build an aircraft before), got frustrated over all the power/weight concerns, paused that, and started to look into R/F equipment...
Knowing that R/F is as close to voddoo magic as an educated EE can allow, I opted to make this the one thing I wanted to keep COTS and simply by "the best" that is out there... and as you might have guessed, I decided that--for me at least, and only based on spec sheet reading--Weatronic will be the best. (Ok, I also am a little biased as I am German, too.). Anyways, not having enough toy money to go all in I elected to combine a DV4 with a--don't judge me--Turnigy 9XR (why spend money on gimbals now if I can buy a BAT 60 later?).
That has been working out fairly well so far and actually is the first R/C project I actually finished (see http://www.thingiverse.com/thing:454290).
With that said, working my way back out again, it is now time to finish that Guillows C172 conversion...

Neither having the weight nor the financial budget, I can neither afford a MUX box nor a LinkVario in the Guilllows. Wanting to "learn" about the Weatronics system, I have a Smart 8 that is in there and, yet again looking forward/back to my goal of having an autonomous multirotor, I have a small UBlox7 in the Guillows C172 that I want to use as a sensor.

I am somewhat experienced with (embedded) electronics and really want to use Weatronic systems for autonomous multirotro systems (Weatronics is FCC legal, has presumably a superb range, telemetry, redundancy, etc. pp. -- i.e. all great things for the "harsh" R/F environment one expects to see on a multirotor. (I do realize that most of you folks here are mainly coming from the other side of the R/C model spectrum--jets--but I believe there is sufficient money in the "DIY multicopter scene" for Weatronics systems, especially given their apparent benefits).

As multirotors require some onboard stability augmentation, pretty much all flight computers compute their own navigation solution from exactly those sensors a prudent safety pilot would like to get information from: GPS, airdata (static and dynamic pressure), magnetic orientations, accelerations and rotations. I.e. all that is necessary to compute attitude and position. But how could I get this data down to me?

My question: Is there any information "out there" about the data protocol used by Weatronic for their telemetry? I.e. what do I have to feed to the "SCU Port" (what does that actually stand for, btw?) to get the Weatronic system to recognize it as valid telemetry data?
(As I said, I have some experience in embedded electronics, so I guess I am simply (?) asking for the protocol description of the I2C/SPI/serial protocol used for Weatronic telemetry.)

Thanks for any shared insight, feedback, or even just a "man, you are stupid"-response

Last edited by hcc23; 09-07-2014 at 08:55 AM.
Old 09-09-2014, 01:59 AM
  #2  
HarryC
My Feedback: (1)
 
Join Date: Feb 2002
Location: private, UNITED KINGDOM
Posts: 3,672
Likes: 0
Received 26 Likes on 16 Posts
Default

Sorry I can't help you with the tech stuff, but it's a good project, the MUX box system is a really bad part of the Weatronic concept. What it needs is a daisy chain serial bus like Multiplex has.
Old 09-09-2014, 06:26 AM
  #3  
hcc23
Junior Member
Thread Starter
 
hcc23's Avatar
 
Join Date: Sep 2014
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default

Hi HarryC

Thanks for taking an interest. I don't have a MUX box so I cannot say whether it is a "good" concept. (Nor could I attach a logic probe in order to try to reverse engineer the protocol... ) I guess the bus vs. hub choice boils down to your preference of lots of small smart boxes vs. a larger smart box and lots of stupid sensors... But my stab is actually not at "bus vs. hub", but more towards the "closed vs. open": If you look at the telemetry systems used in the multirotor community, the ones that are used are the ones where the (open) mutlirotor flight controller folks can get access to the API. I would also argue that there is a point to be made that a public telemetry protocol API will increase the availability of sensors and the proliferation of the Weatronic system.

Yes, this in turn might open up yet another can of worms, the reliability of the data. I guess keeping the system closes gives Weatronic an (presumed?) control over the quality of the transmitted data as they might be able to vet the folks whom they grant access--which is something I can somewhat understand as there is a high potential of blaming the R/C system when indeed the data source is to blame (fictitious former customer 'review'/rant: "My Wea system said I was too fast... I pulled back, stalled, and lost my A/C... stupid Wea telemetry.") And loosing a multi-thousand dollar jet is clearly something different than the cost of a "build, crash, repeat" approach followed by oh so many multirotor folks...

Anyways, I guess I am just advocating for giving consumers and informed choice: Hey, you could simply buy our COTS pieces (MUX box, LinkVario, etc.) and get a vetted, working solution... OR you could DIY your own stuff and get what you pay for. And who knows: maybe the solution is simply to use a half-half approach? I.e. make certain messages closed source (for the vetted systems), and publish others as open for everybody. Then you could later use that information in your recorded data to see where your data was coming from (I.e. Weatronic could respond to that fictitious customer by stating that they had no influence on the speed data as that was recorded by an unaffiliated 3rd party.) Or release the API with an NDA and some language for non-commerical use...

But again, I'd argue that Weatronic could sell a lot of systems if one could "simply" send MAVLink data from your ArduPilot to the ground by simply sending it to the SCA port (be it serial, I2C, SPI, CAN or whatever that SCA port takes...). This combination could provide a really great (and cheap!) solution for a lot of multirotor folks: By a conversion set (which also works with a $50 Turnigy 9XR), and get a reliable --and LEGAL !! -- long range control and data link. And if the DV4's bluetooth can support it, pipe that data directly into a ground station for the "big picture" (or use your DV4 in listening mode once you upgrade to a BAT)...

Well, at least for now I get temperature and battery voltage for "free"... a more or less perfectly steady 5 V all the way until the LiPo cutoff circuitry is starting to make noises that the input voltage to the switching power supply is dropping And who knows, maybe once the BAT hits the market Weatronic will be able to free up some resources to make all these great thinks work

Until then: If anybody knows anything about the protocol: please post it here if you can. Thanks!
Old 09-09-2014, 07:05 AM
  #4  
HarryC
My Feedback: (1)
 
Join Date: Feb 2002
Location: private, UNITED KINGDOM
Posts: 3,672
Likes: 0
Received 26 Likes on 16 Posts
Default

I say it is bad concept because if you want a volt or current sensor, you have to fit a big bulky and very expensive MUX box. The size makes it impossible for many gliders or smaller models, and the cost makes it silly to buy several for multiple larger models. With Multiplex you can fit tiny sensors into small models and just daisy chain them, and can aford to fit sensors into many models. Also Multiplex has always made their sensor bus open source precisely to get the benefits you mention. Multiplex supplies the data to anyone who asks and wants to make sensors for their system even though they make a big range of sensors themselves. If a considerably bigger German firm like Multiplex thinks open source sensor bus is best even though they already make sensors themselves, I can't see a good reason for a smaller firm like Weatronic who doesn't make sensors, to choose not to.
Old 04-03-2015, 06:27 PM
  #5  
hcc23
Junior Member
Thread Starter
 
hcc23's Avatar
 
Join Date: Sep 2014
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Default

OK, I finally (nearly) finished the project I wanted the Weatronic API for: a Guillows C172 conversion with GPS telemetry. (My build thread is http://www.rcuniverse.com/forum/begi...telemetry.html )

I have a u-blox NEO 7M GPS that gives me updates at 10 Hz which I am parsing with an Arduino. I have a spare serial port and I2C available and am ready to send GPS position, ground speed, and vertical speed to the SCU port of my Smart 8 receiver... All that I am missing is the API, i.e. the data format and protocol that the SCU port is expecting.

Is there any hope that Weatronic will make that available? Has somebody reverse engineered the SCU port? (I assume it is a serial port) Has somebody checked what data the Weatronic GPS spits out?
(Is it maybe just a plain NMEA data stream?)

Anyways, let me repeat my plea: Weatronic, please opensource your telemetry API. There is a ginormous market of folks like myself and the multirotor community ready to spend some money on a realiable two way receiver setup. Just think about all those FPV racers that would certainly put very good use to your Tiny 5... 12 cannel PPM and telemetry in such a tiny package... perfect.
Old 05-20-2015, 06:49 AM
  #6  
sidgates
My Feedback: (2)
 
Join Date: May 2002
Location: Denver, CO
Posts: 1,425
Likes: 0
Received 1 Like on 1 Post
Default

hcc23,
I first bought the Weatronic DV3 and 2ea Micro 12 receivers for the best RF connection and the promised telemetry. The RF link has been flawless and the telemetry too expensive and too long coming. For that reason I bought a Taranis to try out telemetry. I have been flying the Taranis for approx. one year and have not had a single malfunction. I have airspeed and altitude telemetry and it works very well. I now have a DV4 Tx module and the adapter to plug into the Taranis. I am going to try the use the first 8channels for the DV4 and use the next 8ch for the Taranis RF and the Taranis telemetry. The Taranis telemetry is Open Source so you could use it for your project.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Manage Preferences - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.