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

[john melia 1]

thats what I thought simon ,

[David...]

I've got the following FrSky telemetry modules (S-Port) and fly all electric craft, this is what I think about their utility:

LiPo voltage monitor - very useful, would not be without it. I have an alarm set at 3.6volts per cell

40A current and voltage monitor - I now consider this almost essential. I have it set to 80% of my 2200mA-Hr batteries.

GPS - useful to know what speed and altitude I'm at, but only just useful, more interesting.

Vario - more accurate altitude and less lag than the GPS, would be more use to me if I was into thermal flying.

RSSI - monitoring and reporting received signal strength I find essential too.

 

Overall I feel more confident in my radio link with the telemetry and in the past Ive had a few stupid lost of control events because I have let my battery capacities go too low, so that should be a thing of the past. I cannot go back to no telemetry now. My Taranis is turning out to be the best radio I've owned and when I compare to others on the market, well for me they don't compare. I can't wait for the version 2.0 firmware which may be out today (01.06.14) come to think of it, I must check now

 

Edited By David... on 01/06/2014 21:55:18

[cymaz]

I monitor my battery packs without Telemetery, just plug a battery checker in before the flight. If it looks low, cancel flight and charge battery. Simples. If you are worrying about the state of the Rx battery whilst in flight- what happened to pre flight checks??

Telemetery has come about as a result of electronic advancement. It has its place. It should not become a substitute for safe practice.

My two pence worth.

[Biggles' Elder Brother - Moderator]

I think telemetry for me falls into two camps:

1. The really useful stuff that can't know too often! The fact that my Tx is sitting there monitoring my Rx battery voltage and the Received Signal Strength and is set up not to bother me with them all the time but to give me a clear, two stage (ie "this looks dodgy" and "this is definitely dodgy"!) verbal alarm if anything does go untoward gives me a nice warm feeling. Yes, I do my pre-flights religiously, but things can go wrong. Its a bit like having a parachute - 99.99%+ of flights you will never use it - but the once you do you might really glad of it as it could well not only save your model it might prevent an unforeseeable accident.

More really useful stuff is monitoring data on mAh's used from the main power battery. Again for me the useful thing is not to have it measuring this then telling me every 5 secs. But to have the system monitoring it in the background and then giving me a verbal alarm at say 65% used and 75% used. As side benefit here being able to know the power being developed in flight - set up so it tells me when I toggle the trainer switch - is also very useful.

2. Stuff that isn't so much "useful" as "interesting" and fun to play with. Now it doesn't really matter how fast my models go - but its fun to know.

All in all - I'd not used telemetry prior to January this year. And I must admit I was at a bit of a loss as to how you would use it - I mean looking down at a screen when flying isn't exactly a smart idea! Now I have used it and seen that I can set it up in the "passive watching" mode I think its invaluable. I wouldn't want to give it up. No its not essential, we flew models before telemetry came along, but it is very useful, can be a significant safety aid and in some forms just entertaining!

BEB

Edited By Biggles' Elder Brother - Moderator on 01/06/2014 23:25:16

[john stones 1 - Moderator]

I don't have any telemetry, I will have some when I buy a Taranis.

But I don't need it to tell me when its too windy to fly. Telemetry between my ears takes care of that.

John

[Rich too]

Posted by cymaz on 01/06/2014 22:36:18:

I monitor my battery packs without Telemetery, just plug a battery checker in before the flight. If it looks low, cancel flight and charge battery. Simples. If you are worrying about the state of the Rx battery whilst in flight- what happened to pre flight checks??

Telemetery has come about as a result of electronic advancement. It has its place. It should not become a substitute for safe practice.

My two pence worth.

I use a monitor in each plane - they cost next to nothing.

Rich

[David...]

I agree, for example a Spectrum Rx about £40 add a TM1000 telemetry unit for £33, then add a voltage sensor lead, total £75

Taranis receiver £24 and a £9.99 LiPo sensor that's half the cost. for a far superior receiver.

[Pete B]

I thought we were just discussing the merits or otherwise of telemetry, David - not having a 'mine's better than yours' contest...

Nothing much has changed in respect of the fundamentals, though. No-one really needs telemetry - the same as no-one really needs more than 4 channels to fly a model. I don't find my non-telemetry models any more difficult to fly than those fitted with it. What it does, and does well, is add a further dimension to the enjoyment of the hobby - as with so many other gadgets - and for those who indulge it doesn't take long to realise the benefits.

Since I last posted back in 2011, I've subsequently upgraded to a DX9 and the value of telemetry has quite simply been elevated to a new level by one facility alone - the introduction of voice reporting of data.

I was a bit disappointed with the DX8 inasmuch as whilst I was getting the data, it really wasn't of much value displayed on the screen. There were tone/vibration warnings, yes, but the permutations to cover the warnings I needed were limited - and I could never remember which sequence meant what when it happened!

Given that the arms aren't as long as they used to be, a quick glance down at the Tx, particularly when thermal soaring at height, was a bit fraught, so all too often, I wasn't able to assess the data until the model had landed.

Now, voice reporting on a wide range of values is there at the touch of a button or at set intervals, as you wish. Rx volts, flight pack volts, amps, mAh remaining, altitude, speed, time elapsed or remaining, the list of options is limited only by sensors and imagination.

I think it's one of those advances that we know we could manage without but, once you've dipped your toe in the water, you'll realise just how valuable and useful it is.....

Pete

[David...]

Agreed. I was (poorly) trying to illustrate that the major manufacturers weren't making (for those that would like it) an easy option to have telemetry and I don't consider their solutions to be value for money. The advent of the Taranis will I hope, bring about a change in the market so this technology is made available for all to use if they need it.

I suspect if it's there in equipment, then most people will use telemetry data, especially if it's got a voice option.

Like you I found the DX8 to be limited, but costly on a model-by-model basis, now these features are beginning to become standard.

I'm wondering what the major designers are thinking just now, they surely must be responding with designs.

[Frank Skilbeck]

I think Pete has hit the nail on the head, you don't need it, just like you don't need the miles left in tank on your car, but it's a nice to have.

And I thermalled up from 130m to just under 300m the other day with the help of my vario, it was thermalling right above us and to be honest it wasn't possible to see whether it was going up or down, but the vario tones enable me to keep in the thermal. The downside was that 300m now becomes a target

[Pete B]

The pricing of the Taranis gizmos has certainly got me passing envious glances, David - it was possible to pick up TM1000's for about £15 on the BMFA site and Ebay when they were of limited interest but those days seem to have gone. They're an expensive, unavoidable essential now - and I can see Spekky charging a premium for telemetry-included Rx's when they introduce them....

Too late, BEB - you're hooked now!...

Pete

[Martin Harris - Moderator]

Posted by cymaz on 01/06/2014 22:36:18:

I monitor my battery packs without Telemetery, just plug a battery checker in before the flight. If it looks low, cancel flight and charge battery. Simples. If you are worrying about the state of the Rx battery whilst in flight- what happened to pre flight checks??

Telemetery has come about as a result of electronic advancement. It has its place. It should not become a substitute for safe practice.

My two pence worth.

I thoroughly agree that safe practice is the basis of competent operation but used properly, telemetry augments safe practice - as an example, I'd refer you to my post at the top of page 7 of this thread, where a battery cell failed in flight...

[Frank Skilbeck]

Posted by Martin Harris on 02/06/2014 23:27:11:

Posted by cymaz on 01/06/2014 22:36:18:

I monitor my battery packs without Telemetery, just plug a battery checker in before the flight. If it looks low, cancel flight and charge battery. Simples. If you are worrying about the state of the Rx battery whilst in flight- what happened to pre flight checks??

Telemetery has come about as a result of electronic advancement. It has its place. It should not become a substitute for safe practice.

My two pence worth.

I thoroughly agree that safe practice is the basis of competent operation but used properly, telemetry augments safe practice - as an example, I'd refer you to my post at the top of page 7 of this thread, where a battery cell failed in flight...

And it's not become a substitute for safe practice, it just means I check my Rx battery pack from the Tx before flight and I get in flight warnings too.

[Erfolg]

Personally I believe that telemetry is very much part of the future RC package. Particularly as a electric flyer.

An example given by others is voltage of the onboard Lipo. Whilst I accept that it is prudent and part of every electric modellers checking regime, not to commence a flying session with a Lipo that is not other than full. It is only telling part of the story.

Looked at slightly differently, how many of us will start a long journey in our road car, only knowing the initial fuel on board, then never checking until the end of the journey how much they have used. Particularly, if stopped in heavy traffic, or the route being particularly hilly, or we decide to drive faster or slower than usual. This would be made worse if the car and journey were new to me. I would be anxious the whole time.

On this basis, knowing the real time voltage of our on board Lipo is invaluable.

Again, until you have and experienced a feature, it is often difficult to access what is useful. Just as reversing electronics on cars, once had, you appreciate that they are a very useful safety device, As I found when a numpty deliberately stood in a blind spot, trying to avoid detection, to find out if I was aware of his presence, The detector let me know there was an issue, that I could not see, and asking him what he was doing filled me with despair as to how perverse some people can be. Previously I had thought why have them, a good look around and all will be well.

I am looking to the day when telemetry is a norm and affordable to all.

Edited By Erfolg on 03/06/2014 08:56:50

[David...]

I'm using the FrSky FLVSS LiPo Voltage Sensor on a daily basis and I'm finding it's beginning to shown signs of wear and tear; it's not really designed for connecting 3 or 4 flight packs per day IMO. SO I've fitted a sacrificial 3S LiPo balance extension cable, that's much better than continuously plugging he pack balance cable in and out of the FLVSS unit, and I can place the module in the fuselage away form the battery compartment.

Hopefully others will find doing this of value too.

[Martin Harris - Moderator]

Very glad I had telemetry today...

One of my models has exhibited reluctance to come out of deliberate flat spins but has always recovered within a couple of turns with the standard technique of opposite rudder/down elevator but today, a normal 6 turn spin flattened and I couldn't manage to recover before the ground intervened.

Initially, I lost signal but the crash site was below a small escarpment and on approaching the location, I regained signal. The problem was that the whole area had been rough planted with maize, standing as high as the proverbial elephant's eye (8 feet at least) and left unmanaged as cover for pheasants (no tractor tracks or rows).

I stood at the nearest edge to the estimated impact point and held the transmitter close to me with my back to the crop. Turning slowly either way I established the lowest aerial signal strength and walked into the maize directly behind me. Repeating the exercise (in range check mode as I got closer) lead me very quickly and directly to the model which was only visible when I got to within 4 or 5 feet of it. Without telemetry, finding it could have taken most of the afternoon - if at all!

As a bonus, the corn had cushioned the impact and there was very little damage so I should be able to fly it again with half an hour or so's work. This technique is well worth bearing in mind in many lost model situations.

[Ian Jones]

A GPS module might be worth considering, I have one on my telemetry and it seems pretty accurate.

[Devcon1]

Can't begin to imagine flying without it now. RSSI or received signal strength, on board battery state at the flick of a switch and altitude callouts.

Reminds me of the life changing experience when we bought our first dishwasher, the thought of doing it all by hand brings me out in a cold sweat...😥

[Phil 9]

I bought a quite expensive Tx just before the telemetry enabled Tx's came out. if it had been an option at the time I would have gone for it. My tx is still going strong and I have no intention of replacing it yet due to cost. As a consequence I have to manage my models without telemetry. My tx also is lacking in voice notifications that is another feature I would like.

my flight times are managed buy the timer for both IC and electric but I do find that after establishing the model energy use over the first 3 or 4 flights the timer method is surprisingly accurate

I was in a similar situation to Martin recently and managed to locate a model by moving the sticks and listening out for the servo noise

I would use telemetry if it was available but is s capabilities are not enough to make be go and buy a new tx just to get them. Or am I really missing out?

[Robert Putley 1]

David,

I need 2S Lipo balance ex lead. Where do you by yours from?

Robert

[Robert Putley 1]

David,

I need a 2S Lipo balance extension lead. Where do you buy yours from?

Robert

[ChrisB]

I've rigged one of my models with some Spektrum telemetry. Altitude, Battery voltage and airspeed.

Its all very nice, but does it change my flying experience? No.

Is it necessary? No

Would I want it on every model? No

All that's really needed is a box with an aerial, 2 sticks and a some switches.

[rcaddict]

robert

**LINK**

[Martin Harris - Moderator]

Posted by Phil 9 on 08/09/2017 08:13:25:

I was in a similar situation to Martin recently and managed to locate a model by moving the sticks and listening out for the servo noise

I would use telemetry if it was available but is s capabilities are not enough to make be go and buy a new tx just to get them. Or am I really missing out?

As others have said, you don't need telemetry but it was that feature that attracted me to the Jeti system when it first came out in around 2009 as a transmitter module based offering and I was considering moving to 2.4 GHz. A vario was bought at the same time as the most obviously useful add on for gliders. Having permanent monitoring of signal strength/quality and receiver battery voltage (standard on all receivers) with the options of real time monitoring of flight battery voltage and/or current under flying conditions, flight and/or receiver battery capacity used, GPS and airspeed (GPS mostly for interest but would be useful in any site radio interference investigations or lost model situation - even if power was disrupted in a crash), and very importantly altitude measurement for safe and legal operation of my larger models are things I really wouldn't want to be without now.

As for finding a model by servo noise, it is useful but I was trying this in the rustling corn in conjunction with the received signal direction finding technique and I found the model before hearing anything at the last "DF" stop.

[Gordon Whitehead 1]

I have spekky telemetry on a couple of models; a big bipe weighing over 7kg, and a Nano Boomerang jet.

The reason for fitting it to the bipe is that our flying field is within the Manchester Airport control zone, and besides needing ATC permission to fly it because of its weight, the model is limited to flying below 400ft. So I set the altimeter warning to 375ft .... which isn't all that high and would be hard to judge by eye.

Even without voice readouts I find the telemetry very useful on the jet. Initially I added asi and altimeter for a bit of fun to see how fast the jet flew as it didn't seem all that fast. The answer came out as about 125mph on the straight and level. In a vertical full throttle dive it maxes at 150mph, both figures being checked after landing. So it is quite slow, but I don't mind as it's a very aerobatic model, and extreme speed is useless for aerobatics.

It's when landing the jet that the telemetry comes into its own. Even though the Wren 44 only has a small amount of residual thrust at idle (55000 rpm!) it's enough to prolong the glide in to land. As our grass strip is only 60m long I need to get the landing speed right so as to comfortably stop within its length - I haven't fitted wheel brakes. Setting the low airspeed warning to activate the tx vibrator at 38mph and below lets me know when the plane is slow enough on the glideslope to get down without floating the length of the strip. To help slow the jet, besides lowering flap I also use crow aileron, along with splaying the twin rudders outwards to create more drag, enabling a steeper approach to landing without increasing speed.

Gordon