Telemetry - do you use it? What do you think of it?

[John Emms 1]

I have telemetry whether or not I want it! I was given the first Jeti module to arrive in UK "to see what I thought of it", and have only ever used the Jeti system since, so that would be since 2008. The Jeti system has receiver battery and reception quality as standard, and I cannot see me ever flying anything more expensive than my indoor models, without it.

I have used current monitoring to check the operating current in all power systems, and I am one of the very few people who knows what my boat power systems draw under load. I have the vario, do intend to use the ASI (for stall warning), and the temperature probe could have saved IC engines on at least two occasions - one on a VERY hot day, and one on a pusher.

[Geoff S]

Most Frsky receivers have inbuilt telemetry to give RSSI readings. They're only really useful for range checking; I've never had a warning whilst flying but it's reassuring to know that your model is getting a good signal.

I have an altimeter/variometer in my Phoenix 2000 mostly for fun and it certainly adds to the enjoyment. I got into a strong thermal on Saturday and it was interesting to hear my altitude rapidly going from 160 metre to 220 when I chickened out because the glider was getting to look quite small!

I've also got a current measuring unit which I use for early flights to get a feel for current draw on electric models. My DB Tiger Moth, for example, draws 20 amps in straight and level flight from its 4S LiPo.

So yes, telemetry can add to the enjoyment of model flying and is a worthwhile addition even though it's not absolutely essential.

Geoff

[Tim Flyer]

I have telemetry with my Futaba 14sg and use it with R7008 telemetry receivers. I always check it in pre flight and post flight to look for voltage drop when giving all the controls a good wobble. I also have the separate voltage reader wired in on my models that have BECs so I can check they work plus the actual battery levels. I find that part of  my telemetry useful. When actually flying looking at the transmitter I find distracting so very rarely check it then . With My Futaba there is no in built microphone for voice telemetry and you need an ear phone! Wearing an ear phone when flying I think would be inconvenient as well as a potential safety compromise. I recently bought the Futaba GPS to try out in my Wot 4 and admit to rarely using it now. I was hoping to use it to search for it if lost in the farmers crop on a deadstick, but the whole thing seems a bit of faff to be honest and a rc audible alarm might be better for my needs.

Edited By Timothy Harris 1 on 08/09/2017 13:17:47

Edited By Timothy Harris 1 on 08/09/2017 13:21:04

[Andy Green]

For me telemetry is something I'm using more and more, from engine temp to actual consumed current from my flight batteries.

The problem with most radios is that you only get the data reported back.

I'm a recent convert to Jeti and can use the data in alarms, functions and mixes, which now makes it useful.

Andy

[Chris Bott - Moderator]

I've got so used to telemetry I feel something's missing if I fly without it. Frsky's Rx level and Rx battery monitoring are in every Rx. I have lipo current/volts monitoring in most models so always know how many mAh it's used and get warnings if pack volts get low.
I fly with plenty of confidence about my batteries.

[Erfolg]

What is very noticeable is that two names keep popping up. That is Spektrum and Frky (Which I assume is Tararnis).

It seems that generally the other principal manufacturers are missing out, be it by pricing point or as a convenient feature.

The very first usage of telemetry i saw was on a F3J type glider using Jeti, since then I think I have only seen two others with Jeti. One i know (I think) does not make use of any telemetry, the other, not a clue. I guess it is a price thing.

Although I have seen a few Taranis, I am not sure that in my circle of acquaintances, make use of anything beyond the occasional independent variometer. Which makes me think, at least in the short term, there is room for a low cost Radio independent system. Perhaps this is where the forgers should put their efforts, probably making more hazzle free profit?

[Frank Skilbeck]

Yep I use telemetry for monitoring Rx battery voltage, lipo voltage, amps and mah used and vario in my gliders, with alarms set to alert me to low Rx voltage, low signal quality, low lipo volts, high amps and when a preset mah used is reached. Not essential but nice to have and it has picked up a faulty Rx switch which probably saved a model.

The other day a fellow flier hide his glider in the tall ferns where we fly, took the GPS co-ordinates off his transmitter and then entered them into his phone, I was able to walk to with in a couple of meters of where the model was. As on the same day a walker had handed me a crashed model (not mine) that he had found and I had previously found a model on the same hill that had been lost the previous year, it's not a complete waste of money.

BTW Erfolg, you can buy a Jeti box and then use a Jeti Rx to send telemetry data back to it, also the standalone varios can also send back a voltage measurement also. But the company that did the Safe to Fly voice telemetry systems stopped selling these around 3 years ago, no market probably as it's pretty hard to buy a radio system these days that doesn't have it inbuilt.

[Erfolg]

Frank

I no longer (really) fly any gliders, although I have and do think, that the data storage aspect, would have been helpful.

I have the same issue as another contributor to this thread, I am happy enough with my radio, a Futaba 8FG. I have considered buying the low cost Taranis, only to baulk at the idea of learning how to use it. I recently installed a WIFI Extender, it only took me 4 weeks to get around to installing it, just to much bother. I now feel old. Everything I use I expect to be intuitive, simple to use, if not, I have much more important things to me to do.

I am the only one on the thread, who is looking forward to the benefits. Like many others out there, I am not prepared to pay any real money, nor learn, just use. I bet there is money to be made of the likes of me. there are lots of late adopters out here.

[Andy48]

Posted by Erfolg on 08/09/2017 16:59:27:

Everything I use I expect to be intuitive, simple to use, if not, I have much more important things to me to do.

I am the only one on the thread, who is looking forward to the benefits. Like many others out there, I am not prepared to pay any real money, nor learn, just use. I bet there is money to be made of the likes of me. there are lots of late adopters out here.

Sigh! Whatever happened to lifelong learning?

Its no good having telemetry if you don't do something with it. If you are going to do something with it, then that involves a learning process.

[Ian Jones]

The Jeti telemetry sounds good, I've been using HiTec for years though. Very happy with it.

[Devcon1]

A prediction but maybe a far off dream.

I'm no techspert but I cant see any reason why we shouldn't be seeing force feedback stick telemetry at some stage.

Translating servo loads into force feedback stick units via telemetry seems very plausible to me even with current technology.

Imagine feeling the pull on the stick as you progress through a loop or the force on the rudder as you do a Lomcovak.

One day. ( Also stick shakers)

[Devcon1]

Too quick on the key.

 

Edited By Devcon1 on 08/09/2017 20:11:39

[Erfolg]

Andy

As one who took ONC, HNC, BSc (Hons), undertook further studies in Materiel Technology, had more certificates for safety than I could shake a stick at, I came to realise, that knowledge is fine to do your work. There is also a case in doing what you like doing. Some things should facilitate the main task, not require work to get to the real task, just to get to do what you want. When or if you reach the age where news announcements about what will happen in 20 years time are seen as irrelevant to your time frame, you centre more on what actually interests you.

I am one of the few people who has a Microsoft phone, it down loads pictures, almost automatically, deletes and files pictures automatically, it is not only intuitive, it does not require even basic thought. This contrasts with my wives Android system, or even my daughters Apple. You have to do things, not just make decisions, to achieve the same in a much longer time frame.

From a telemetry system, I will expect the same. I do not want to learn, just make decisions. I want it all, on a platter.

Being honest, this is also what i now expect from my radio. Life is far to short.

[Andy Green]

Jeti already have heptic feed back, albeit just stick shakers, but wont be long until they are full force feedback.

Andy

[john stones 1 - Moderator]

Posted by Erfolg on 08/09/2017 20:20:52:

Andy

As one who took ONC, HNC, BSc (Hons), undertook further studies in Materiel Technology, had more certificates for safety than I could shake a stick at, I came to realise, that knowledge is fine to do your work. There is also a case in doing what you like doing. Some things should facilitate the main task, not require work to get to the real task, just to get to do what you want. When or if you reach the age where news announcements about what will happen in 20 years time are seen as irrelevant to your time frame, you centre more on what actually interests you.

I am one of the few people who has a Microsoft phone, it down loads pictures, almost automatically, deletes and files pictures automatically, it is not only intuitive, it does not require even basic thought. This contrasts with my wives Android system, or even my daughters Apple. You have to do things, not just make decisions, to achieve the same in a much longer time frame.

From a telemetry system, I will expect the same. I do not want to learn, just make decisions. I want it all, on a platter.

Being honest, this is also what i now expect from my radio. Life is far to short.

Do what makes you happy Erf.

[Martin Harris - Moderator]

Posted by Devcon1 on 08/09/2017 20:08:11:

A prediction but maybe a far off dream.

I'm no techspert but I cant see any reason why we shouldn't be seeing force feedback stick telemetry at some stage.

Translating servo loads into force feedback stick units via telemetry seems very plausible to me even with current technology.

Imagine feeling the pull on the stick as you progress through a loop or the force on the rudder as you do a Lomcovak.

One day. ( Also stick shakers)

It's taking a long time - I strongly recall visualising such a system back in the late 70s when I started full size gliding and became aware of the "feel factor" and was still flying models but realised the technology of the time couldn't support it at any reasonable cost/weight. The seeds of wanting telemetry were planted back then - probably a major factor in buying in to Jeti as soon as I saw it mentioned (within a day or two) in the new products feature in RCM&E.

Edited By Martin Harris on 08/09/2017 22:58:26

[Mike Blandford]

I'd feel quite lost without telemetry. I've been using FrSky telemetry for 6 years, with voice output for 5 of those. While beeps were useful to start with, it was always difficult to look at the Tx display to see telemetry values, having voice means you don't need to look away from the model. (I implemented voice output on the 9X type Tx running er9x firmware, and was one of the first (if not the first) to have voice output).

I have various voice reporting controlled but switches, and the volume controlled by a pot, so I choose what I need to hear, and can adjust the volume while flying so it is low when there is not much other sound, but when a loud IC engine is running nearby I can increase the volume to hear properly.

Erfolg: Actually don't just equate FrSky with Taranis. The open source firmware (er9x/ersky9x/openTx) run on a variety of transmitters supporting both 'D' and 'X' FrSky Tx modules and the associated telemetry.

In ersky9x (and er9x) I've tried to make setting up the voice output as straightforward as possible, so there isn't a huge learning curve to be able to use it. You simply have something called a "Voice Alert" and configure what you want to be played together with the conditions under which it is played.

Adding feedback isn't to difficult, but you clearly need a sensor to monitor loads in the 'plane, and hardware in the Tx to provide mechanical feedback. Tying these together is then not too difficult. With the open source firmware, you coud very likely add a script to provide the feature, requiring very little actual software development, just enough for the script able to control the mechanical feedback, since scripts already have access to al the telemetry data.

 

Mike.

 

Edited By Mike Blandford on 09/09/2017 00:31:02

[Bob Cotsford]

Mike, I would have thought that a current sensor in each servo feed would provide load feedback easily enough, but how much bandwidth is available for the telemetry? What effect would all the additional sensors have on data rates?

[Erfolg]

Considering various uses some have outlined within this thread. Also considering some reports of CAA officials or their representatives turning up at model shows, from description on a informal basis. Not withstanding the various reassurances i have received from the BMFA and others, that the result of the EASA proposals, will not have any material impact on how we operate now. I have come to think that some of the ideas, can be implemented now.

The height restriction of 400 feet, it appears at least one contributor is already using telemetry to advice in real time that they are on going beyond this height.

From some comments that some have made with respect to GPS, it appears that it is possible to achieve a similar horizontal measure, probably a radius.

I guess there would be a requirement for data logging, as evidence of compliance. Hmm, which could mean that you would need to hold the data somewhere for some time. A bit of a headache IMO, for many of us, who just fly as a easy going fun activity.

If these regs come to pass, as I have interpreted the present proposals, I can imagine that even those of us who do not presently have any telemetry available, will be required to acquire some, as a stand alone system, or to buy a new RC set that incorporates what is necessary.

Either way, there would be commercial opportunities for manufacturers.

[Martin Harris - Moderator]

Posted by Erfolg on 09/09/2017 10:34:13:

The height restriction of 400 feet, it appears at least one contributor is already using telemetry to advice in real time that they are on going beyond this height.

I have implemented a stage further, where I use a telemetry control to cut the throttle to idle at 400' - not perfect as a "zoom" climb can obviously exceed the preset altitude but prevents an unintended steady climb above the limit. It could, of course, be refined with the addition of attitude/airspeed sensing but I'm happy with that and a voice warnng at present.

[Mike Blandford]

I'm not sure a current sensor in a servo lead would work. The servo would take current as it moves, but many servos, with a light to medium load, would probably not take any current (consider pushing on an unpowered servo arm), and if it does need a holding current, this occurs in pulses rather than a continuous current.

Regarding telemetry bandwidth, you need to consider what resolution you need. For example, a FrSky 'X' Smart Port data packet holds a 32-bit value. This could be 4, 8-bit values from 4 load sensors. I would think a load value sent as -127 to +127 would be more than enough resolution.

Data logging:

erksy9x and openTx both support data logging. For powered flight, I know some uses have their Tx set to start logging as soon as the throttle is advanced, so the logging is automatic.

Regarding storage, looking at some log files of mine, if you log 30 values, once per second, you need about 500K bytes of storage for one hour of logging. Many users have a 4Gb SD card (or larger). A 4Gb card would therefore store around 8000 hours of logging data, which is nearly a year of continuous flying (24 hours a day!).

Because the 400' height limit has existed for specific areas (e.g. controlled airspace), I've had a 400' (122m) height warning in er9x/ersky9x since the end of 2011.

Mike.

[Dickw]

Posted by Erfolg on 09/09/2017 10:34:13:...........

I guess there would be a requirement for data logging, as evidence of compliance. Hmm, which could mean that you would need to hold the data somewhere for some time. A bit of a headache IMO, for many of us, who just fly as a easy going fun activity..............

Just checked my data logs, and 4.5 years of regular flying has resulted in only 230Mb of data stored on my Jeti Tx - which I regularly backup on my PC for me to play with or analyse at leisure.

Logs are produced automatically as soon as I first open the throttle, and contain signal strength and quality plus Rx supply volts for all models, plus power system measurements and flight data for most of the models (volts, amps, rpm, altitude, temperatures, and in some cases GPS and G force data)

Doesn't seem like data storage is going to be a problem, particularly now I have a 16Gb card in the Tx!

Dick

[Erfolg]

Martin, Mike, Dick are confirming, what I thought, from the general contributions, that what I had at first thought was going to be a major tech problem, if some of the EASA suggestions were to be implemented immediately, in no such thing.

The idea with respect to a servo height limiter, seems could also solve the issue with respect to FF models. As many already make use of mechanical, elecro mechanical and electronic devices for all manner of things, although mainly DT function. It would of course change the whole nature of competitions, if something along those lines became mandatory.

The issue for the dinosaurs, oh, that is me, is I need something that can run alongside my existing (basic RC) system. There would be a short term market for bolt on supplementary systems. In the longer term all the manufacturers would out of market and compliance necessity make built in Telemetry systems basic to all sets.

Not what I initially thought what Telemetry main use would be, seems I could be wrong again about the future. For me it is a slight embarrassment, for manufacturers, it is about money, market share and a future.

[Frank Skilbeck]

You can already buy height limiters which shut down an ESC, they are used in E Soaring competitions. Another one here.

[Erfolg]

Yep, I should have known that, given that the then UK team manager trialled such a device a couple of (or that is what it seems) years back, at our fields. Then a number of competition fliers only flew their models with them in. I remember the emphasis changing from gaining as much height and distance in 30s, to one of slower climbs looking for some tactical advantage.

Although this type of device is here, I wonder if it is the most appropriate for the average club flyer, if height limitation came into being. Particularly if you consider the slope soaring fraternity

Those were the days when i saw what I now know to have been exotic machines and systems on a weekly basis. Where expensive and some not so expensive (although of unknown brands to me) RC came and went, like a change of clothing.

Now at a different emphasis (not silent and quite) club, the interests are very different. Powerboxes, large digital servos, engines that are seen in small and not so small motor bikes, along with many jet engines, is a very different world. The things that interest so called glider guiders (by them) leave them apparently cold.

Our hobbies desires, wants and needs seem to be pretty broad.

Edited By Erfolg on 09/09/2017 14:10:28