Tutorials for Stabilization and Telemetry on FrSky Taranis X9D with OpenTX

[DonStegall]

I love telemetry. As a software engineer, I have to have data to analyze things. You cannot guess when building software systems. Everything has to be discreet and deterministic or you don't get 100% accuracy.

We can't get 100% accuracy with model aviation. But just as people have found radar equipment to be very useful, telemetry gives new insights.

I have worked with almost all of the Spektrum telemetry modules including one not under the Spektrum name, but it is for Spektrum only. That is the Evolution RPM Telemetry Adapter (EVOA113) https://www.horizonhobby.com/evolution- ... er-evoa113 and I use it on all of my gasoline engines.

I have a FrSky Taranis X9D transmitter that I got for FPV drone racing. I'm getting ready to start using it for planes as the telemetry sensors are less expensive than the Spektrum sensors. The FrSky system does not have it's own stabilization system built in.

I'm going to be investigating other systems like this one Flex Innovations Aura 8 https://www.flexinnovations.com/product-p/fpzaura08.htm that works with most PWM servo systems. If I only have to know one system, that would be a little easier. I already know Spektrum AS3X, so the learning curve should not be too big.

According to the information I have, even sponsored Futaba pilots can use third party stabilization in their pylon planes, but this thread is not the place to discuss that.

Here is an introduction to the FrSky telemetry sensors.

https://www.youtube.com/watch?v=cK_R4MG7qXY

[fizzwater2]

"The FrSky system does not have it's own stabilization system built in."

I think they do. I've heard of some folks experimenting with them.

FrSky S6R and S8R - receivers with stabilization.

[DonStegall]

Thanks Fizz,

I have not gotten any of the PWM compatible FrSky receivers yet. I was going to get the RX8R PRO but I will check out the ones you listed.

I will be running engines this weekend and my gas test stand with servo controlled throttle and choke, plus telemetry, and my GoPro will be getting a workout. Will probably test some AMA class racing engines and motors too.

[DonStegall]

"The FrSky system does not have it's own stabilization system built in."

I think they do. I've heard of some folks experimenting with them.

FrSky S6R and S8R - receivers with stabilization.

Thanks .. Looked it up on Amazon and that listing does not show telemetry unless I overlooked it https://amzn.to/2FlXCys

But the HobbyKing site shows it as having the newer bus telemetry and I ordered the S8R from Amazon for delivery on Monday.

Will be going to pick up my Taranis x9D this weekend from a friend working on one of my quads.

I was going to put another Spektrum in a Quickie or a Club Wingman plane but now I will be giving this one a try. Possibly in a little P-51 Mustang EP Voodoo with retracts if the 8 channel fits. Stabilization make those little planes fly much better. And the Voodoo is much lower cost than the other planes. The Wingman II may be a better platform to really test it out on before moving to the glow stuff.

You probably saved me quite a bit of money .. So thanks again .. at the minimum I will get to try the Trananis on a plane. I just haven't flown with it recently.

[DonStegall]

After researching the FrSky telemetry and stabilization equipment, I got the following:

FrSky S8R 8/16 Channel Receiver with 3-axis Stabilization

FrSky STK Tool for S.Port Products Upgrading and S6R/S8R receivers Configuration

FrSky FLVSS LiPo Voltage Sensor with SMARTPort

FrSky Smart Port RPM and Temperature Sensor

I have watched a number of videos and read a fair amount.

I will probably try to use the FrSky system on electrics and not glow or gas.

I am excited to try the FrSky telemetry equipment as I love the Spektrum equipment for telemetry.

One thing that Spektrum has over the FrSky is the Castle Telemetry Link X-Bus, Spektrum Compatible that let's me see into the ESC and get RPM, current draw, temperature, flight battery voltage, and more. I don't know that the motor wire RPM sensor is going to work with the 50+ volts of the 50cc equivalent propulsion system for my 50cc Pilatus PC-6 Porter - ARF. I'm probably going up to a 100cc equivalent motor since this thing is going to weigh 30+ pounds.



The Gas RPM FrSky sensor does more than the Evolution/Spektrum one which only does RPM, but I may find a use for the FrSky Gas Suite Smart Port which can "Monitor in real-time RPM and the gas flow velocity - Enable and disable the ignition control system manually". I'm already adding an Opto Kill switch on my gas planes, so the $110 for the Gas Suite may be worth it.

Evolution RPM Telemetry Adapter

Unless I can get this Spektrum Aircraft RPM Sensor and Bracket to work with the FrSky, I will use Spektrum on glow planes for sure. Especially for AMA 422 Q40.

Spektrum Aircraft RPM Sensor and Bracket

I had to go get another gallon of WEST SYSTEM 105/206 this afternoon as I'm doing so much mold making, I used a gallon this week.

Probably going to start buying the 4 gallon resin / 1 gallon hardener C Size from now on, at least until the molds I want to make are done.

[sahartman21]

Don,

We have been experimenting with the FrSky S6R receiver.

1) The receiver works fine with electric and typical 40 powered models.
2) We had issues when using the receiver with Q40 models.

The extra vibration appeared to be the problem with a Q40 model. I removed the received and shook the receiver. The vibration had wollered out the case until the board was vibrating around in the case.

I suspect that these issues can be overcome. We have some thoughts but they have not been tried at this point in time.

[DonStegall]

Don,

We have been experimenting with the FrSky S6R receiver.

1) The receiver works fine with electric and typical 40 powered models.
2) We had issues when using the receiver with Q40 models.

The extra vibration appeared to be the problem with a Q40 model. I removed the received and shook the receiver. The vibration had wallered out the case until the board was vibrating around in the case.

I suspect that these issues can be overcome. We have some thoughts but they have not been tried at this point in time.

Thank you very much Scott

This is why I post messages here and on other social media.

I prefer to learn from others whenever I can instead of wasting time, effort, and money.

Have you guys tried the Hall Effect gimbals ??? FrSky M9-R Hall Sensor Gimbal for X9D/X9D Plus Transmitter

At $24 (I guess each) they might make the controls nicer.

A friend has an antenna upgrade and the antenna is removable. I like that possibility. I found this on Amazon https://amzn.to/2YfTGrD

I ran my DLE-35RA on my telemetry equipped Tripos Test Stand this evening. Got the results I expected and got video of most of it. I'm going to create a wiring diagram before finishing and publishing the video. The engine is now ready to go in a TWM P-51 Mustang G.S. and I will be working on that in parallel with other projects. I'm looking forward to having some big planes to fly on the course at OJA. Hopefully they will let me fly this one at the local clubs also. I'm not going with the O.S. GT 33 because it is LOUD. And while it may be a few mph faster, this one should be welcome at the Warbird Fly-In events.

[DonStegall]

You do not want to use velcro to hold a stabilization receiver down - the receiver can move out of phase with the airplane. Using double sided foam receiver tape to both secure the stabilization receiver and also null some of the vibration out is a better method.
...

All my stabilization use has been on electric planes. And not big ones yet.

I've had no trouble with stabilization on the electric planes with the receiver just velcroed in place. (Spektrum receivers .. mostly the AR635 and AR636)

After talking to an active Q40 racer (which I will be again soon) today for a bit, he mentioned using ties around the receiver. I think if you use ties, you should isolate them even if it is a harder material.

He mentioned a gel pad. I use gel pads on acoustic drums to control overtones. It would seem like a good solution but based on what you mentioned, there could be phase issues on planes that vibrate. I mentioned taking the receiver PCB out and shrink wrapping it. He made a good point that doing that on both sides could lead to the receiver overheating.

I just got the FrSky S8R receiver today. The USB connection thing will be here tomorrow or Wednesday, but it will be next weekend before I can do much with the Taranis and the S8R.

I started this thread so I could help others and so I could pick up real usable info and not speculation.

From the emails, calls, and other communications, it seems that people are just shy of talking about these topics because of "The Vote".

Personally, I enjoyed the R/C Pylon column by Mr. Seaholm in this issue and found his candor about his vote and opinion refreshing.

Hopefully nobody jumps on this and they have me as a "Foe" if they don't like what I write and share.

If people are afraid to plug a computer into their planes, they are going to get left in the dust.

All I'm trying to do here is facilitate knowledge sharing. I have a lot of followers on Facebook for a reason.

BTW, if one can talk, they should be able to type a coherent message or email. All I do is type what I would say. It's called conversational writing and AT&T spent a lot of money back in the 70's and 80's teaching their people how to do it. That's why you have UNIX, Linux, Android, macOS, iOS and too many things to mention that came out of AT&T.

[DonStegall]

...
If people are afraid to plug a computer into their planes, they are going to get left in the dust.
...

Let me clarify this statement.

I do not mean left in the dust on the course. I mean left in the dust of R/C technology.

When proportional radios came out, many were afraid of them. Not my father, Jim Stegall. He had one as soon as he could afford it.

Even with proportional radios he continued to "bump the sticks" ... I'm sure it hampered his heat times ... But he made up for it with pure flying skill and timing.

I will never beat a Randy Bridge or Travis Flynn or Richard Verano or many, many others, unless they double cut out.

But I can work to refine my plane setups just as a Jim Katz or Dean Stone is a master at setting up a plane trim, throws, balance, engine technique, etc.

All the while I will be honing my flying skills. With or without stabilization or telemetry.

I may not even use stabilization turned on in my glow planes for a while. I want the pilot skills and to be able to actually know when stabilization is working for me, or not.

[DonStegall]

Joe DeLateur.

I have heard you are working with the FrSky equipment and have a solution for getting RPM via the crank pin on glow engines.

Are you using the Spektrum Aircraft RPM Sensor and Bracket ???

And are you using the FrSky Smart Port RPM and Temperature Sensor to get the signal to the FrSky receiver/telemetry system?

It should be relatively simple to adapt the FrSky two wire RPM input to either a crank pin sensor or gas engine tach output.

I guess I have to break out the electrical engineering skills now unless there is a simple solution.

[delateurj]

Hi Don,

Yes I have created a converter that takes the Sprektrum rpm signal (which is just a square wave) does a little averaging and outputs the rpm in the format needed for the smart port telemetry input used on the S6R ( and several other Frsky rxs).

HW is based on the Moteino https://lowpowerlab.com/shop/product/99 which is an Arduino variant. It is mainly used as a radio transmission platform but you can buy it without the transponder.

SW leverages a library https://www.rcgroups.com/forums/showthr ... nfigurable for using the Smart Port protocol with one parameter modified so I could get a higher transmission rate.

The device is small thin and light and I usually slide between the fuse side and the tank.

Attached is the modified library and my moteino code. If you would rather not try to come up to speed on the arduino environment and program the moteino, I'd be happy to send you (or anyone else interested) a programmed moteino for the cost of one plus shipping (They are $12.95, so lets say $15). Use at your own risk, the moteino is powered from the rx, so a failure in the moteino could take down the rx battery.

I've also created a LUA script so I can view the telemetry on the Taranis. This from a 424 run but I have been primarily using it on 426. Have about 30 flights with no problems so far. Will be putting in my 422 next. Will consult with the others to avoid vibration issues.

All in all I am happy with the way it works. I use the RPM on the tx screen on the line. Some have said they think that is too laggy. The lag should be 130-200ms between the communication rate (10hz) and the averaging (10 pulses) I am doing. I'd be surprised if neither the Master Tach or Fromeco didn't have lag from filtering/averaging and response time of the analog meter in the case of the Master Tach.

(Edit to specifically answer your questions: Yes, I am using the backplate rpm sensor. No, I am not using the FrSky Smart Port RPM and Temperature Sensor. However, that might work in place of the moteino. In other words that device may take the output from the Spektrum sensor as its input (in place of the two poles of brushless motor it expects). Let me know if you try that. I'll probably stick with mine since I think its smaller and less expensive and I know what its doing. The Frsky device is just looking for square wave coming from 2 poles of brushless motor. However the specs say 2s-12s so a min. peak voltage of around 6 volts. The Spektrum is a 3.3 volt square wave, so below the stated spec, but I would not be stunned if it still worked)

Regards,
Joe DeLateur.

[DonStegall]

Joe,

Thank you very much.

I just got the S8R on Monday and I went to my friend Irwin Funderburk's house to get my Taranis X9D Plus. I had forgotten that mine is the Plus edition.

I demoed some guitars amps for Irwin, but it got late and we did not actually bind the receiver to test it out. Looks like the S8R has multiple modes and I figure I can use the USB STK for setting it up.

I've got a serious work deadline this week and I didn't think to order the male to male leads until last night. Then I forgot to hit the "Place Order" button on Amazon, so I won't have the telemetry connectivity until later in the week.

With me having so much mold making in progress, I'm just going to wait until this weekend to take a deep dive into the FrSky system. I'm excited enough about what I see, I'm going to wait to set up my electric 50cc equivalent motor system until I see what all I can do with the FrSky. I love the idea of open source.

So thank you very much for sharing.

From the photo it looks like you may be changing the plug on the Spektrum RPM Bracket Sensor. Since the other plug seems to be proprietary, that would make sense.

I definitely want to get one from you. Please send a PayPal invoice or money request to Don@DonStegall.com

My son Matthew is now a JavaScript guru and web developer using Go and React. Back when he was in high school we got him a bunch of Arduino equipment when Radio Shack was still open and had the stuff. I got him the full experimenter kit with the stepper motors and other stuff.I helped him some with the programming initially but he went way beyond what I helped him with. I think he used the Uno and the Nano. One thing he built used 4 servos to move a frame around in different shapes. He's only 24 years old now, but he and his bride of 6 months just signed a contract for a nice big house to be custom built near where he works at Red Ventures in South Carolina. I call Matthew my Wonder Son because he is so good at conceptualizing things and making them work. I have his Hakko Soldering Station and he has an Arduino project he want to do. So I have to get the station back to him. Think I'm going to get this Hakko FX888D-23BY Digital Soldering Station FX-888D FX-888 (blue & yellow) for myself as I finally used it Saturday night and for a change, soldering was fun again. If you have a soldering station recommendation, please let me know.

if your unit is easy to build, I might be interested in selling them on Amazon. I know that many R/C airplane pilots moving from Spektrum to FrSky would be interested in them. I am going to start using telemetry in all of my planes, including sport planes if the FrSky works as good as it looks like it dones. And I love the reasonable prices.

I was thinking about getting the M9 Hall Effect gimbals, but I found this on Amazon FrSky Taranis X9D Plus Transmitter - Black Customized Special Edition - w/ M9 Gimbals - Carbon .. I always have two of each kind of transmitters, or at least compatible transmitters. I don't like the idea of a wasted travel weekend because of something like a transmitter switch getting broken. With the M9 gimbals built into the customized one, I can see if I want to switch out the gimbals in my stock X9D Plus. I'm probably going to put the high gain antennas on them too. Irwin says you just have to be careful when installing them, and using the right pigtail connection. Any comments on this strategy are appreciated.



Irwin has always done my FrSky and drone racing equipment building and setup. I was so hampered by my health issues in 2017-2018 and my wife's issues in 2018 I just didn't have time to do much more than try to fly some drones. He kept me in the air with the FPV racing quads.

Obviously I'm back in gear now and playing with new stuff is going to be a lot of fun.

I talked to Scott Hartman for a while yesterday and he recommended a new forum for this thread and other related to radios. I think that would be a real good idea, as the other FrSky forums are overload for a lot of people with all kinds of drone info.

Thank again,

Don

[delateurj]

Hi Don,

For now I just moved it to Building Tips. Will look at creating new forum and replying to your post later. Gotta run right now.

Thanks,
Joe.

[DonStegall]

Joe,

Thank you for sharing, I talked to Matthew about the Moteino. He looked at the specs and said it should be nice for building all types of telemetry os S.Port devices. He knew the processor and it's capabilities.

Thanks for sharing the code. I only saw one modified .h file in the __MACOSX folder (on my PC) and I could not open that file on the PC. DIdn't have time on Tuesday to try it on the Mac.

I like your device better than trying to hack the FrSky RPM sensor since it is around $25-30 by itself.

Even though I would not use the FLVSS battery sensor in a glow plane, I plugged it into various packs from 2-6 cell and I really like it. The previous version, the FLVS-01 was able to be daisy chained to work on up to two 6S1P so you can monitor 12S1P.

If I can use two FLVSS to get the voltage for my 12S1P I will be using on the 50cc Pilatus PC-6 Porter, I may go with FrSky instead of Spektrum on that plane. It depends on if I can use FrSky 150A Current Sensor.



On the PC-6 I want to be able to use the Castle Telemetry link to monitor the motor and ESC for current draw and RPM mainly. So Spektrum is the choice for that since I can also get the internal ESC temperature. But getting the cell performance would be very nice as well. The plane is big enough and at around 30 pounds, a little added weight is not a big deal. I may use a redundant telemetry system with both the Spektrum and the FrSky. If I can find out how to have a redundant control system, that would make it even better.

With the Moteino, I may be able to create an RPM sensor that works with the gas engines and the hall effect timing sensor so that I don't have to buy the $100 Gas Suite.

Do you mind sharing a circuit schematic or wiring diagram for your device? I will make sure I credit you in any uses of it if you want.

[delateurj]

Hi Don,

"From the photo it looks like you may be changing the plug on the Spektrum RPM Bracket Sensor. Since the other plug seems to be proprietary, that would make sense." Spektrum actually sells a version with a standard servo plug or you can change the plug. The picture was of a friends. I actually use the proprietary plug.

"I demoed some guitars amps for Irwin, but it got late and we did not actually bind the receiver to test it out. Looks like the S8R has multiple modes and I figure I can use the USB STK for setting it up."
There is a LUA script that allows you to configure the SXR from the tx. I find that the easiest way to go. The USB STK can be difficult in getting to behave correctly. Sequencing of when you connect and when you launch app is particular or else it won't connect. Very frustrating...particularly for a systems engineer...so I just use the LUA script. For upgrading the firm ware there is a method of doing it from the TX using the pins in the module bay...if you have trouble finding those instructions let me know. Definitely upgrade the RX and definitely explicitly disable the stabilization if you are not using. Defaults are dangerous.

I have special edition from aloft hobbies with M9 gimbals. Very happy with it and in general I think Aloft is great to work with. Curious about high gain antenna. Please share more details when you do that.

Sorry about leaving out the wiring info...will post that shortly.

With regards with can you use it and do you need to credit me.... The heavy lifting was all done by the library posted by Pawelsky on RCGroups.
He does include the following at the top of his code which includes the phrase ("Not for commercial use"), so I would check with him/credit him if you are going to expand on this.
/*
FrSky telemetry class for Teensy 3.x/LC and 328P based boards (e.g. Pro Mini, Nano, Uno)
(c) Pawelsky 20180402
Not for commercial use
*/

Regards,
Joe.