HPA

Be sure to detail your electric gear.  I have wanted to try electric free flight for years but just don't have the knowledge.

Well you know, there's not a  real lot to know, you need a motor -most probably a geared one- fitting for the prop diameter and , a controller pcb, and a battery (most likely LiPo 1s)...  ;D
Of course you can make a whole science topic about it, but from my experience best is to just start.

Some thoughts and experiences on these components:
- Motor: there are tons of different motors, gears, props out there, but most likely I would suggest to buy a set, motor + gear + prop to start with. Just to be exact, in general we use brushed motors as those are easier to control (electronically). For example I use a ø8,5mm x 20mm motor with a 52x10 gear and a 6 x 3 prop on a 600mm wingspan Cessna with a total weight of app. 55g.
- Controler (Electronics): also on this, a huge varitety of possibilities available, but also some specifically designed for Free Flight, e.g. the Zombie Controler (Atomic Workshop), which I can only recommend due to its low weight and simplicity. It's widely used in electric FF so far I know.

- Batteries: as usually weight is the most demanding factor on planes, it's always been a challenge to decide on the amount of "fuel" to be carried, especially on electric FF. Today, we have thankfully a big variety of LiPo-Batteries at hand, which in it's nature are the lightest possible electric power sources available today, and thankfully also in very small sizes. With a proximate flight time of just a couple seconds to a few minutes, I for example decided on using a 150 mAh battery on the set-up mentioned above, and still think about reducing it to 75-100 mAh. So, here as well, my suggestion to buy a decent sized one and see how it goes, reduction should still be possible.

I have split the last messages from the original Piper Tri-Pacer build thread, as the subject is more universal and useful as a stand-alone topic for others too.

To begin with, we are talking mainly about indoor electric scale models as they are being flown under the FAI F4E provisional class rules, mostly flown in Europe. I have no experience about what is done/flown in the US or other countries, so any input on that is most welcome.

In F4E, the models are judged on flight realism, as long as the flight duration is over 15 seconds in order to be considered as a qualifying flight.

In order to achieve that, the most important piece of equipment is the motor "timer", or "profiler", which allows some pre-programming of the motor's RPM and run duration.

The first and most successful profiler so far, as correclty mentioned by Sven, is the Atomic Workshop Zombie timer, which revolutionised the CO2/electric class after its appearance. Until then it was a class dominated mostly by CO2 models, with very rare appearances by electric models. Now, over 20 years later, it is the other way around, with CO2 models virtually non existent in events like the BMFA Indoor Nationals.
https://atomicworkshop.co.uk/product-category/flight-profilers/

Another option that was (is?) available was the K+P timer.
http://kpaero.com/ProductReport.aspx?Category1=electric


More recent addition to the choices is the "Chronos" timer by Jiri Dolezel (excellent choice of a greek word  ;D , meaning "time"). (Sorry, no known link, unless Jiri can provide some more info).

All three definetely operate on 1S batteries, if I am not mistaken. I do know that the Zombie can run on higher voltage, I imagine the others too, with some circuitry. More specialised input welcome.

There is also the timer made by Tonda Alfery's son, which is sadly not commerically available.

Last, there are some attempts in progress, to program the motor run via specific RC systems or even a mobile phone up, as was demonstrated at the last IIFI. Nothing specific yet, although Erik Crins should be posting something relevant soon, I hope.

Some major characteristics of each of the available options (if there are others out there that I did not mention, by all means add them to the discussion...)

Zombie Profiler

• very light at 1,25 gr.
• brushed motor operation only
• two separate power phases, time and RPM setting for each phase via onboard potentiometers
• ramp option to run power down
• no separate servo operation
• start button to start operation

K+P timer

• slightly heavier than the Zombie
• brushed and brushless operation, via external ESC
• 3 potentiometers for power, duration and decay, requiring a combination of all 3 to arrive at a required flight profile
• no separate servo operation
• operation start immediately upon connecting the battery

Chronos timer

• slightly heavier than the Zombie and the K+P
• brushed and brushless operation, via external ESC
• 3 potentiometers for power, duration and decay, requiring a combination of all 3 to arrive at a required flight profile
• additional servo operation possible, for landing gear operation for examble, two extra potentiometers
• operation start immediately upon connecting the battery

The immediate operation start of the last two is a problem that can be easily overcome through an additional switch, giving enough time to place the model for take-off.

There is also another profiler I failed to mention, mainly because I have never seen it in action or owned one.

It is the one marketed by SAMS, now available from the Vintage Model Company.
https://www.vintagemodelcompany.com/dual-function-profiler-bomb-drop-version

It is not clear if it drives a brushed motor without the use of an external ESC. It seems to drive a brushless motor with an external ESC.

It also has a servo operation for a "bomb drop", meaning probably a one-way servo actuation.

not much more can be gleaned from the website of VMC, I am afraid.

   Great survey George, you must spend so much time reading and adding content, it is much appreciated.
Just a slight correction, the K&P Timer comes programmed with a 10 second delayed start after it is switched on. Also there are separate K&P timers for brushed and brushless motors.

Thanks Dave,

yes, it is a bit time consuming at the moment but I think it is worth it.

Regarding the timers, you are correct, or, I was not clear.

All have a 10 second delay, more or less. It is just that the activation is different. The Zombie does not start upon battery connection, it needs a specific action for the clock to start running while the others start upon battery connection.

As for the K&P, the one I had was for brushed and brushless. And that is what I see on the website too.

  Well there you go, I thought that while they sold a Brushed Timer the others were only Brushless. I also have a fellow flyer that has just bought a brushed timer for his twin KPO2 powered B25.

Quote from: g_kandylakis on Feb 14, 2026, 02:42 AMThere is also another profiler I failed to mention, mainly because I have never seen it in action or owned one.

It is the one marketed by SAMS, now available from the Vintage Model Company.
https://www.vintagemodelcompany.com/dual-function-profiler-bomb-drop-version
not much more can be gleaned from the website of VMC, I am afraid.

It and a range of controllers for similar purposes is made by Forge Electronics https://www.forge-electronics.co.uk/index.php/aircraft.html 

It is also available from Den's Model Supplies for the UK https://www.densmodelsupplies.co.uk/index.php?c=e-zee_timers who sell ten variations(!)

And a couple of the versions from Steven's Aero for the USA https://www.stevensaero.com/product-category/model-airplane-supplies/model-airplane-receivers-servos/ez-timers-control-line-freeflight/

Enjoy browsing!
Nigel

This is part of a longer( :o ) reply I wrote about K&P timers on HPA2.0. The situation is fairly confusing:

KP sell two timer/controller types which are connected quite differently. One type is used directly between the battery and motor in the same way as Atomic Workshop Zombie flight profilers are used. This type effectively incorporates an ESC.  I've attached scans of diagrams from their instruction below but one is illegible so I may have copied that from a screen image.

The other type is used in conjunction with an ESC and effectively replaces a radio control receiver signal to control the ESC. The schematic that can be downloaded from the KP product list 'Time and Speed Controller' hyperlink refers to this latter type kpaero.com/Documents/KP%20freeflight%20TIMER.doc.

Unfortunately, the instructions that are supplied with KP timer/controllers appear to refer equally to either type as 'KP Aero Timer'. I have a 35 sec timer (item #112 on their product price list) recently bought wherein the instructions show a wiring schematic for a brushless motor which does not/cannot relate to the controller in the box, so I haven't scanned those instructions. The controller unit supplied has two three-pin 'Futaba' connectors with markings for Aux and Motor, no battery connectors, +5V S1, Signal S2 and S3 solder pads, so I haven't a clue how to use that one properly, although I suspect one simply connects the ESC to the Motor connector. I will ask when I come to use it. That's an aside.

As far as I can follow their terminology and the photos available, the 'time and speed controller' supplied with the KP01/KP02 motor/gearbox/prop/battery/controller combinations, #7 and #9 on their product list labelled 'KP 01/02 LiPo + Accessories', appears from the website photos to be different from the 'Brushed motor time and speed controller 10A' (item #120) I have in front of me. I don't have the former so I can't be certain. The product description for KP01/02 states, "The 'with accessories' option includes a single li-poly cell and our low voltage protection brushed time and speed controller", so I would conclude those controllers are for use with 1S LiPo's only.

However, item #120 'Brushed motor time and speed controller 10A' is rated for 1S or 2S LiPo's but doesn't as far as I can make out include a low-voltage motor cut-off. To do so would require quite sophisticated circuitry to detect the number of cells when they are initially connected, store that information, set a cut-off voltage parameter, etc. Most battery chargers do this; I can't see any mention of such in the KP instructions. A bit remiss because at best, the user might or could ruin their batteries by over-discharging them. The design perhaps relies on the timer feature switching off the motor after the run and decay periods. I've scanned the relevant instructions below.

The KP 'Time And Speed Electronic Regulator 35 Sec/120 sec/ 10min' controllers, items #112/113/114 respectively in the price list are used in conjunction with an ESC in place of a radio control setup. That's quite a clever idea because it offers almost complete freedom to time and control any electric model's electric motor/s. This timer/controller doesn't limit the power you want to use nor constrain flexibility of motor/ESC/prop choice, it simply provides a control signal to the motor via a conventional ESC.

HTH, although I doubt it!
Nigel

A new one, still being developed but very near completion is the 'Tempo' flight profiler. It is a two part system, a flight profiler in the plane and an app on one's phone that is used to adjust the settings - no presets or access required. The settings are all sent by Bluetooth when the start button is pressed,so no fiddling about at the start of a flight.

I did try it at last years' IIFI but it wasn't really ready, and was far too rushed. It was accepted by the judges.

One of the big problems with indoor electric models is the effects ot the state of battery charge. This uses an algorithm to adjust the power as the battery discharges to maintain  consistent flights.

It looks complex in the photos - lots of wires. These are mostly optional to allow external on & off, led, safety link, etc without having to directly access the device.

With any luck it should be ready, and available for anyone who wants one, in a couple of weeks or so.

Hi Allan,

nice to read about this!

A few questions and comments.

What is the expected weight of the unit when finished?
Size of the board seems about 3,5x2cm, right?
Brushed motor operation only or brushless as well?

If I understand it correctly, you press start on the phone and all settings are transferred to the profiler, so there is no more communication with the app during the flight?

This would be described as a 4-stage timer, right?
Take-off, climb, cruise, descent. (leaving idle out...)

And any idea about the cost?

If there is no signal exchange after the start button is pushed, then I see no reason at all why it would not be accepted as an alternative profiler by judges in IIFI or BMFA competition. It is certainly more precise to input power and time values digitally than by rotating tiny pots.

George

Hi George,

Thanks! In answer to your questions...

The unit as shown is about 4 gms.

The PCB is 34 x 19mm. Height is about 6mm. Some of the wires are optional, depending on the installation.

This version is for brushed motors using 1S lipo, up to 5 amps, and is aimed at indoor use. There's another version, aimed at outdoor flying, for driving an external ESC for 2S upwards for either brushed or brushless. Driving an external ESC means no upper limit on voltage or power.

Yes, that's correct. When you press the start button all the settings are sent and cannot be changed until the flight ends. There is an Emergency Stop on the phone, so this will send a stop command if pressed. I'll get a better picture of the screen for you.

Yes, but has landing as well, which might be helpful making a flair just before touchdown. Settings for each flight phase are in percentage power in 1% steps, duration of transition from last phase to next 'Ramp' in seconds, and duration of the remainder of that phase in seconds. This means very precise control of each phase. The 'Ramp' effectively eliminates the kick that effects trim when changing power level.
Another advantage is trimming can be done in baby steps.

Several model memories are available, like standard RC practice. Also one unit is bound to one phone, a bit like standard RC.

Cost would be around 85 UKP / Euro. To be confirmed. A website with full instructions, Youtube links, etc is under construction.

Thanks Alan...

One other aspect I forgot to mention in the beginning of this profiler discussion, is availability for purchasing.

I am not sure if the Zombie and K&P are indeed available, there was some shortage at some pointwith the Zombie, if anyone can confirm, please do.

The one I know is available, is the Chronos by Jiri Dolezel which was on sale at IIFI 2025 and apparently soon this one by Alan.

Erik Crins is working on something as well, initially for himself, I do not know if it will be made available to others too. Still waiting to see his presentation, hopefully soon.

George

We expect it to be available in the next couple of weeks or so.

I must hastily observe that this is a collaborative effort and by no means all my own work. The software and App have been written by Dave, who's details I'll share when I've checked with him that its OK to do so. He has also produced the brushless version for an external ESC.
My role has been on the seemingly endless testing and reporting back, and for the schematic & PCB design.

Hi,
I'm Dave, collaborating with Allan on the Tempo flight profiler, and I hope that it'll be of interest.

Allan has described the version that he is working on, intended for 1s batteries driving a brushed motor.  This turned out to be a bit more complex than the version that I had created, which works with brushless motors on 1s, or 2/3s with a BEC equipped ESC.  It is NOT suitable for brushed motors on 1s - hence Allan's development - but might work ok on 2s, as you'd have to use a BEC equipped ESC - but I can't see anyone using a 2s/brushed motor system.



The Tempo 'Cardinal' (so called because it first flew aboard a Veron Cardinal)  weighs about 2.4g - here's a video of that first flight...


and here is one of Allan, trying out the 1s version indoors...(accursed walls..)

Those timers are amazing.

For a somewhat simpler, somewhat lower tech approach, this thread about capacitors may be of interest:
Supercaps for free flight models (https://www.rcgroups.com/forums/showthread.php?4032135-Supercapacitor-Power-for-FF)

Note that you can charge to lower voltages for shorter flights with less power, or use a lower farad capacitor for shorter flights but the same power.

Sam in the discussion above has a Guillow Skyraider which flies well with a geared motor and supercap: https://www.rcgroups.com/forums/showthread.php?4508439-Supercap-Guillow-s-Skyraider/page2 (https://www.rcgroups.com/forums/showthread.php?4508439-Supercap-Guillow-s-Skyraider/page2)
He also has a 24? inch Taylorcraft he flies indoors. The sonex413 channel on Youtube has a bunch of supercap flying.

If memory serves, there is a discussion on the web of the Peterborough timer and even a version which allows you to walk away before the motor starts. You have to make it yourself from several components, though you don't necessarily need a circuit board.


I'm impressed with how much power can be obtained from physically small capacitors. Years ago, I had a housemate who made an amazingly good stereo. The capacitors on his homemade amps were the size of beer cans.

One vendor who has a bunch if interesting little motors is Micron Wings in Australia. However, I think there are good suppliers in Europe as well. I think the coreless motors are lighter thn KP for their power, although if you need nose weight anyway, maybe it doesn't matter.

I wonder if anyone is doing supercap Ebenezers?

Very nice, Dave and Allan!

That looks like a ESP32, right? That does also do the Wifi connection?
I have thought of something similar, maybe with an ATtiny85. That would of course, not have the comfort of using Wifi for configuration, but maybe be a bit lighter?

Very interesting project!

Cheers
Alex

I've played around with supercap power, and the Peterboro timer, and they're both excellent low tech methods - and it was the sonex youtube channel that got me into supercap power, love the videos there.

The Tempo is based around an ESP32 C3 Supermini.  When I first had the idea, I looked for the smallest bluetooth enabled microcontoller - turned out to be the Supermini.  IT also has onboard wifi - but this uses a lot more power than the BLE (Bluetooth Low Energy).

I'd already written umpteen Android apps using the wonderful online editor at MIT App Inventor, hence going this route, apologies Apple users - but it still took a long time to get it all working reliably, and I think we've cracked it now - thanks to Allan for doing the testing!

I did think about an ATtiny version to save weight ((I'm more familiar with the Arduino mcu's) - but then you need to somehow get your flight profile from the phone to the mcu in the model...I did think about IR, but few phones have the required IR output.

At the mo, I'm playing with the smaller ESP32C3 mini-1 module, which is lighter than the Supermini - but so far proving to be a headache.

Thanks for the interest, I hope to have the website up soon, cheers.

fascinating - it's great to see experimentation like this happening. here's to all the small time developers and suppliers. :)

Good luck with it.

John

Hi Dave and Allan

Some thoughts triggered by this thread so far:

• I do like the idea of using an app on a mobile phone to input and control the timer.  The use of pots and pushbuttons in current alternatives seems pretty clunky.
• I can understand wanting to develop one of an Android/iPhone first.  However, when you get a moment to develop the iPhone alternative app, please do so.
• Are you considering just making a DT timer version (i.e. no electric motor control issues)?  This looks like a real advance on the BMK system if you do.
• On the subject of DT, I have been wondering about whether a better actuating system that those currently available (band burner or servo) would be the 2 second powering up of a small electromagnet - my idea is that the DT line would have a small magnet the +pole of which attaches to the end of the core of an electromagnet that is usually off.  When the timer runs down it will charge up the electromagnet so that the relevant end of the electromagnet becomes the + pole - the two = poles repel each other so the DT line is released.  This seems simpler and possibly lighter than the current alternatives.

I really wish that I knew how to create an iphone app - but, personally, have always avoided Apple products and have no knowledge of how to go about it - from the little reading that I have done, it looks to be fairly complicated.  If there are any amateur developers out there willing to have a go, I'd welcome the contact.

I did look into an alternative route that uses a WiFi connection, with the flight params  entered via a webpage form - which would work on any platform - but using a wifi connection took a lot more power, drawn from the flight battery.  The clue's in the name, BLE....

Regarding auxiliary function such as D/T....  the present Tempo Cardinal (the brushless version) does have an extra pin brought out - the idea is to connect a beeper to this and the app has a field to enter a time value - this many minutes after a flight ends, the pin will go high and activate the beeper - but it just as easily be connected to (say) a hot wire D/T - or I might alter the programming to output a servo signal to activate a D/T?  Lots of possibilities here, and I thought it best to see what others thought for now.

Gaah...should have thought of this earlier...here's a draft copy of the user guide, which describes the widget in great detail.  IT also has the instructions for the kit version - this involves a fairly simple job of soldering some fine wires and should be doable by anyone with a little soldering experience.

Jeremy, Re your point number4. BMK already does a lightweight solenoid for DT and it has had good reviews.
Ron

Quote from: cvasec on Feb 23, 2026, 12:59 PMJeremy, Re your point number4. BMK already does a lightweight solenoid for DT and it has had good reviews.
Ron

Thanks - I had missed that

Hey, good morning.
I made also a timer in the last week.
Its programmed via a HandDataTerminal with an oled display which is pluggeg in for the Setup. The HDT can work with any flighttimer code/ pcb version in the future.

In the moment there are 5 flight phases with ramps, 2 esc out, 2 servo out and one led out for flashing/ position lights, this version measures 15x22mm and i made also an smaller one with only one esc out which measures 12x18mm.
At the moment the pcb´s are getting produced in china and i guess near the end of may they will be here and populated. I´ll keep you informed if there is anything new.

Matthias

Its now finished.
This is the mini version with "only" one esc out and 6 flight phases with 6 ramps. Also a lightweight extention for programming is possible.

Flight Timer Programming Sequence
1. Power On
When power is connected to the timer, the system starts immediately. At this point, the ESC output is held at zero throttle. The timer first checks whether a programming hand unit is connected. If a hand unit is detected, the timer enters programming mode and the motor sequence does not start. If no programming hand unit is detected, the timer continues with the normal flight sequence.
1.1 Hand unit connection
The pcb of the Hand programming unit connector must face the outer edge of the flighttimer.

2. ESC Initialization Time
Before the motor sequence starts, the timer waits for the programmed ESC Init Time. No motor phase is active during the ESC initialization time. This value should remain at 1/ 2 seconds.

3. Optional Start Button
If the Start Button option is disabled, the timer automatically continues after the ESC Init Time. If the Start Button option is enabled, the timer waits after the ESC Init Time until the start button is pressed.

4. Start Delay
After the ESC Init Time, or after the start button has been pressed if the start button option is enabled, the programmed Start Delay begins.

5. Ramp from 0% to Phase 1
After the Start Delay has finished, the motor sequence begins. The first step is the ramp from 0% throttle to Phase 1 Power.
The duration of this ramp is set by the parameter Ramp 0->P1.
If the ramp time is set to zero, the output changes immediately to Phase 1 Power.

6. Phase 1
After the ramp to Phase 1 is complete, the timer holds the ESC output at the programmed Phase 1 Power. This output is held for the programmed Phase 1 Time.

7. Ramp from Phase 1 to Phase 2
When Phase 1 Time has finished, the timer ramps from Phase 1 Power to Phase 2 Power.
The duration of this transition is set by Ramp P1->P2.

8. Phase 2
After the ramp is complete, the timer holds the ESC output at Phase 2 Power.
This is maintained for the programmed Phase 2 Time.

9. Ramp 3 to Phase 6
As described above.

10. Motor Off
After Phase 6 Time has finished, the motor sequence is complete and the ESC output is set to zero throttle and remains at zero.
The timer does not restart the sequence automatically. To start a new sequence, the timer must be powered off and powered on again.

That sounds excellent!
Would it work on supercaps as well or lipos only?

I would be interested in buying one of the tiny ones :)

Cheers
Alex

Quote from: AllanP on Feb 19, 2026, 04:21 PMCost would be around 85 UKP / Euro. To be confirmed. A website with full instructions, Youtube links, etc is under construction.

Dave and Allan

Just wondering if the website for this is up and running yet, and if it is still coming, when do you think it might be available?

Quote from: SvenH. on Feb 12, 2026, 11:06 PM- snipToday, we have thankfully a big variety of LiPo-Batteries at hand, which in it's nature are the lightest possible electric power sources available today, and thankfully also in very small sizes. With a proximate flight time of just a couple seconds to a few minutes

For short enough durations, supercaps will be lighter especially if they enable you to omit the timer. For instance, let's say you have a 40 gram model and you want a minute of duration. Looking at Sam's* supercap information, and at Digikey, maybe you'd use a 20 F supercap that weighed 4.8 grams. If I'm not mistaken, that cap is rated for around 20 amps! I'm assuming that the current is 2amps. With a lipo, maybe you'd use a 100 mAh battery from Nick Leichty that weighs 2.7 grams**. However, if you didn't want it to fly away, you'd need a timer which would probably weigh at least a gram. So, 3.7 grams instead of 4.8. on the other hand, for a 30 second flight with a capacitor, you'd only need 10 F, weighing as little as 2.8 grams. The lipo with timer would still weigh 3.7 grams.

*See the free flight section in RC Groups. At the moment, two of these discussions are "sticky" and appear at the top. Free flight, unfortunately, is a subforum of one that is called exotic, or something like that.

**Oops, maybe the lipo weighs 2 grams. However, the 10 F cap is lighter than that lipo with a 1 gram timer.

Let's look at what you might need for one of those Comet 54" models. I'm guessing we need on the order of 10 amps. A 100 F cap, which we'll assume is good for a 1 minute flight, would weigh maybe 22 grams, and a 50 F might be 13. If we go by the ratings, which I'm a bit skeptical of, a lipo capable of that much current might be only 5 g without the connector. Let's add 2 g for more robust timer. If we look at hybrid caps, a 300 F rated for 10 amps might weigh 9 or 10 grams. (It seems to me that the hybrid caps now have lower resistances than I remember.) We'd still need a timer. So, for a 30 second flight, it's 13 grams for a regular 50 F supercap, 11 or 12 g for a hybrid supercap plus timer, and maybe 7 g for the battery plus timer. For a 1 minute flight, the regular 100 F supercap would be 22 g. These are all SWAGs*. YMMV, especially in another year or two. To get a more accurate comparison, it would take more time than I want to spend. However, at most we're only talking about a 15 gram penalty on a 200 gram model, with more convenience and less complexity.

For a short motor run, perhaps 8 seconds as you might use in an E20 model, I think the supercap probably comes out lighter. But maybe not in open E20, where your power system has to be capable of 3 motor runs. At least according to the PMFC rules.

Hi lincoln,

you have a point in your calculations comparing Lipos and capacitors. Indeed a lighter solution could be achieved with a supercap.

But the use of a cap without a timer is not the best solution for the F4E indoor class.

The aim here is to dublicate a realistic flight with a minimum of 15 seconds in order to be a qualifying flight. A flight of 30-50 seconds is usually enough for a good score by the judges. Less is not going to sore well, more is dangerous (walls-ceiling) and unnecessary.

For realism you need to be able to adjust the motor speed, not just go full power and this is where the timer becomes necessary. In order to have climb, cruise and descend. It can be achieved maybe without a timer, much like a CO2 powered model where the power also gradually decreases, but there are too many variables for that to work.

I do not know if a timer would work with a cap, I imagine it would but haven't tried it.

The complexity is not with the battery but with setting up the power/flight profile as required.

George

If the voltage is always above 3V then it should work.

Apologies for not getting back sooner - got carried away working on yet another version of this!

The website is now up and running, link below.  At the moment, we have only the 2s version on offer, whilst Allan is wrapping up the 1s version:

Check out:   https://www.dva-controls.com/

I did have a play around with the WiFi side of things - an html form is held on the ESP and, when you connect to its own wifi, this form downloads to the device (Iphone or android), and here you can enter flight values before returning them to the widget.  However, it did not have the flexibility of an app and, crucially, the power consumption when running wifi on the ESP was prohibitive.

But then, I thought about the BLE link and how to do away with it - which led me to build a device that appears to be very similar to the one described here by Matze - I use the popular 'Cheap Yellow Display' as a configurator - and the flight params are transferred to the much smaller widget (uses an ATtiny85) via an infra red link. 

Amazing how things change...it took me the best part of 2 years part time pootling to create the first version, but just a few hours to create this one - with the help of AI for the coding.  I'm just now waiting for draft pcb's to come, before trying it out.

cheers, Dave

Here's a short video of the forthcoming Tempo Solo - a flight profiler for 1s LiPo and lightweight models....the flight profile is entered on a separate gadget and then transmitted to the model via an infra red link, and you can hear the motor ramping up/down between phases.  The Fokker has been flying, needs a little more tweaking yet!