Switching off

[carlp]

Is there a 'safe' way to switch off the unit rather than just unplugging the power? I have another Pi connected to my TV and it always 'complains' if I just pull the power and sometime even corrupts the OS?

Carl

[Admin]

Is there a 'safe' way to switch off the unit rather than just unplugging the power? I have another Pi connected to my TV and it always 'complains' if I just pull the power and sometime even corrupts the OS?
Carl

Hi Carl
You can quite happily pull the plug on PAW, I spent a lot of time creating some  software magic so that would not be a problem

Thx
Lee

[Kurt37]

Hi there,

I know there is black magic so that the Rosetta can be shut down by pulling the power cable. However as maybe known from the powermouse thread I am planning to connect the Rosetta with a Flarmbat. I will make a 3d printed box to contain all parts including a Flarm booster and a powerbank and all cables. It would be rather a shame to have to disconnect the cables, because the box is made very space efficient. (my powerbank actually has an on off switch,but when I charge the powerbank the poweroutput is all over the place+I don't want the Rosetta to be damaged+it should run while charging the Powerbank).

Is there a way to neatly in operate an on off switch? I guess the gpio 3 and ground switch are connected and therefore blocked by the (antenna?) Board on top.

Kind regards
Patrick

[exfirepro]

Hi Patrick,

The easiest way is probably to carefully open the casing of the power cable and insert a small switch into the main power wire (the obvious thick one). I know of several users who have done this.

You can buy cables with switches, but they are usually not heavy enough for the potential 2 amp current draw.

Regards

Peter

[Kurt37]

Just to confirm: power cable between power bank and Rosetta?

Something like this?

https://www.amazon.de/dp/B083Z2ZJ5G/ref=cm_sw_r_cp_apa_i_AGtgFbZMVG4MF

[exfirepro]

Yes,  though that one looks possibly a bit ‘heavy’ for the job. It only needs to switch 3 amps at 5 volts.

Take a look at something like this, found on Amazon.de...

Taiss/10pcs Solder SPST ON/Off Mini Boat Rocker Switch 2Pin Toggle SPST Switch Snap with Lines KCD1-X-F

Sorry, for some reason I can’t post the Amazon.de link here.

Regards

Peter

[Crash one]

Excuse me bumping this up. But, tried the Rosetta for first time today into East fortune (hope I didn’t upset too many with my rather split assed approach)
However. Connected it to the aircraft 12 volt system through a cig socket/usb adaptor.
Master switch on, press engine start and it only just started, low battery performance!
I can only assume the Rosetta is drawing a fair current out of the battery as this is the first indication of flat (new) battery.
Power pack seems the answer or remember to start first before switching on. Does the Rosetta really draw that much current?
Also I got “loss of Flarm data” all the way home, and, as advised, assumed it to be a power problem.
Is this likely? The only other electric item is the TRT2 radio.

[exfirepro]

Hi Crash,

Sorry I missed you today - I had hoped to pop over to Keith’s fly-in (all of a few hundred yards from East Fortune to East Fortune East) but was off up Aberdeen way testing PAW Ground Stations and the about to be released new software. I flew over Kingsmuir and would have dropped in but had a tight schedule so couldn’t spare the time (You may have left by then anyway).

Although we say that your supply must be capable of supplying 2.1 Amps without the voltage dropping below 5 Volts, PilotAware rarely actually draws that much current, so unless you have left it powered up for a significant period without the engine running, (e.g. left it on overnight) I doubt if that was why you had starting difficulties. I can run a Rosetta from a 20000mAh powerbank (optimistically rated and nowhere near the capacity of an average aircraft battery) for over 18 hours.

In practice, we always recommend starting your engine before powering up PilotAware, but not because PilotAware will affect engine start, in fact exactly the reverse - engine start can easily pull the aircraft battery down to the point where the power adaptor fails to maintain the minimum 5 Volts and the PilotAware cuts out.

If you are concerned, give me a call - I will message you my number.

Best Regards

Peter

[Crash one]

That’s what I thought, that the engine would “drain” the paw first.
I’m going to try to get out to Kingsmuir again today, Monday. With a fully charged battery + the power pack and check things out. One or two questions if you’ve nowt else to do, or I’ll give you a buzz.
Thanks Peter

Trevor, Harvey

[Admin]

Hi Harvey

Are you using an anker USB adapter ?
Thx
Lee

[Crash one]

I am yes.

[JCurtis]

Some back of the envelope (well, iPhone calculator) maths, if you left a PAW powered by the battery with everything else off...

Whilst a PAW can draw up to 2.1A, generally when running it draws an average of 750ma, or 0.75A.  But that is at 5v, so we need it convert it to 12v, by going via Watts.

Watts = Volts * Amps

At 5v this is 3.75W.

So now back to Amps for 12v, but we will add 10% to the Watts to account for the converter being only 90% efficient.

Amps = (Watts * 1.1) / Volts

At 12v that is 0.34A

Them for an approximate discharge time, divide the battery Ah capacity by the draw in Amps at 12v to see how long it will last.  Though to be able to start assume it needs 25% charge remaining.

So for a 20Ah battery, that equates running it flat in ~59 hours.  For engine start then ~43 hours.

Naturally, finger in the air roughly, your milage may vary, objects in the mirror are closer than they appear, and such disclaimers apply.

[Crash one]

Well, 98.7 % of that went clear overhead but a 40 amp hr battery should start a Continental C90 plus run the Paw without much trouble?
It seems I have a flat battery!!!

[exfirepro]

Hi Trevor - that’s about the size of it.

Also remember the temperature was well down yesterday morning, which can also lower battery voltage. Several needed ‘jump’ assistance to start at East Fortune yesterday.

Regards

Peter

[Crash one]

Tried today. Battery flat, swing prop, flew for 50 mins, batt even flatter wouldn’t move at all, Kwik Fit tomorrow! Nothing to do with Paw just coincidence timing! Leuchars reporting bad radio reception.