Change Tx Power Dynamically

I'm primarily using my Deviation powered 7e to fly a Hubsan X4 via a A7105 module with PA. Mostly I'm flying around the room, so have the Tx output power set to 100uW which is enough for that limited range.
Sometimes, I fly it out into the back garden and then want to range out into the neighbourhood - which would obviously require a higher Tx power output.

So :-

• Can I change the Tx output power value, say from 100uW to 10mW, whilst my model is bound?
• If so, will the output power change immediately (or can it be made to), or will it only change after a power off/on cycle?
• And finally - If it does (or can be made to) change immediately, would it be reasonable to request an enhancement to allow the assignment of the power output setting to a trim switch so that it could be easily changed whilst flying?

Ian

Interesting idea... if my bird flies away, I press some trims to catch it...

To be serious: I am not sure if it is a good idea to have a button to decrease the power...
And I am not sure if the A7105 PA recognized the different power settings (or works with a constant power and ignores the setting).

Interesting and novel but useless feature. Just crank up the power to 10mw or 30mw and be done with it, you won't lose much flight time (I assume this is why you keep the power so low).

I say useless because it would get used for all the wrong reasons and people would crash their expensive aircrafts then come here and whine. I mean people are already complaining because they are able to lower the output too much and somehow the firmware doesn't alert them, and they proceed to destroy their helis and planes.

I might sound very blunt, but just give this forum a read and you'll see what I mean. For every person using something correctly, there are 3 doing exactly the opposite.

Right - I'm back home so I've been able to do some checking with the model / Tx in front of me.

The result is . . .

• With the model bound, motors idling and the Tx on an indicated 100uW, I could walk about 7 meters away before the signal was lost and the motors stopped.
• Walking back to the Tx, changing the power to 1mW, with the motors still idling, I could walk about 17 meters away before the motors stopped.

Admittedly not very scientific, but hopefully enough to indicate that the output power _is_ being changed dynamically without loss of signal to the model.

I wonder how much effort it would be to include the Tx output power value as the target for a mixer?

Would anyone else support such an enhancement request?

Ian

sbstnp wrote: . . . you won't lose much flight time (I assume this is why you keep the power so low).

Hi sbstnp - thanks for chipping in (I think ) - blunt is good.

I got through my first Tx battery charge in a little over an hour of flying with the Tx set at 10mW.
Having carried out a range check, I reset the Tx to 100uW, and have set up a permanent timer to keep a more accurate track of the battery time.

So far, I've had 1h30m of flight time on the new charge, and the Tx has only dropped 0.3V (from 5.35V to 5.05V) assuming similar battery drain (a big assumption, I know), I should get around another three hours or more of flight time before the alarm comes on - that's one hour vs four and a half hours.

Maybe this isn't enough data to draw a solid conclusion yet, but it seems that this feature would not be useless _to me_ , and maybe some others too.

With support in the mixers, it should be feasible to program this feature with safety in mind, such as only being possible to increase, not decrease, power during flight, or setting a minimum limit.
That's why I'm raising it here, to gauge reaction. If it doesn't get support then so be it.

However I'm not sure I agree with your main reason for giving it the thumbs-down.
The major benefit of projects like Deviation is that they offer people choice. There will always be people who make ill infomed choices, and unfortunately some of them will want to pass the buck.
The best that can be done is to try and make sure that users are as informed as possible (and after all, use of Deviation is soley at the users own risk, and anyone not willing to accept that risk can freely choose not to use Deviation).
I personally dont think restricting the choices of everyone based upon the bad experiences of some, is the right way to go. Just my two pence.

Ian

FDR wrote: I think changing it manually is pointless...

However if you have a rssi telemetry data, that could be used to adjust the tx power automatically as needed.

Like having the Tx power output as a mixer target, and telemetry data as a source?

Heh, I hope you didn't take offense, it was not my intention

Another argument against such a feature would be that the 7e is almost at the limit of ram/flash, and what's left could be used for much more useful stuff

But, if you want to implement this, by all means go ahead, truth be told I am curious about how such a feature would work in reality.

Of course no offense was taken, a forum is exactly the right place to exchange views

I have taken a fork of the Deviation code, and am beginning to find my way around. Maybe I'll take a look into whether this would be feasible to do within the constraints of the 7e. But, age is taking its toll, and I'm not quite so quick on the uptake as I used to be

Ian