PilotAware

British Forum => Technical Support => Topic started by: marioair on June 19, 2019, 09:04:56 pm

Title: Losing connection with switching apps in iOS
Post by: marioair on June 19, 2019, 09:04:56 pm
I was wondering if you can help - I'm being bounced between various people to find the answer!

I have SD using PilotAware as GPS source all running on Ipad Mini ios12

If i minimise skydemon (switch apps or go to home screen) after about 5 mins (reproducible consistently and even at home when not flying) it will lose the GPS/Wifi from PaW. It comes up with the "no signal received for some time..." message

I'm pretty sure its a PaW problem, as when i use the IPAD internal GPS and switch SD to background, SD still works fine, so I think its something to do with the wifi connection to PaW

I dont know what you relationship is with the SD team but can you tag team a solution?
Title: Re: Losing connection with switching apps in iOS
Post by: Ian Melville on June 20, 2019, 06:47:56 am
Which version of SD and which iPad Mini?
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on June 20, 2019, 08:39:40 am
I can't make it that easy for you :-)

Ipad mini 4
iOS 12.3.1
SD 3.12.6.183

I've tried it on Iphone 6s, iOs 12.2 and it seems fine.
Title: Re: Losing connection with switching apps in iOS
Post by: Paul_Sengupta on June 20, 2019, 10:33:14 am
While maybe not being consistent behaviour between Apple devices, I'd have thought this was expected behaviour. When an app is put in the background, it'll eventually be stopped from using up battery and comms resources, so its Wifi access will be cut off. Personally I'd have thought that putting the app in the background would cut off the Wifi access from it fairly quickly, so 5 minutes is quite a long time to have a background app still communicating over Wifi!
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on June 20, 2019, 11:07:36 am
Perhaps. You can flag it to always use location in background but suppose it may not do the same with WiFi
However it works fine on on the iPhone
Title: Re: Losing connection with switching apps in iOS
Post by: Admin on June 21, 2019, 07:55:52 am
Hi Mario
I don’t believe this is a PAW problem, we continue sending the data to the ipad so long as it continues to accept the data

What 3rd party connection method are you using in SD

The fact that it works on some devices also rules out PAW I think

Have you posted this on the SD forum?

Thx
Lee
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on June 21, 2019, 08:14:04 am
I’m using the pilot aware option in SD 3rd party connection settings
Title: Re: Losing connection with switching apps in iOS
Post by: Admin on June 21, 2019, 02:21:25 pm
OK, so this is sending UDP Packets to the iPad - irrespectively
so SD either stops listening, or the iPad blocks the data, as the app is asleep

can you please post on the SD forum, and provide a link here ?

Thx
Lee
Title: Re: Losing connection with switching apps in iOS
Post by: Grem on June 21, 2019, 03:09:34 pm
I get the same problem using an iPad mini 3, IOS 12.3.1 and SD 3.12.7.  I suspect the problem is, as suggested, with the IOS switching off the Wifi connection to SD when its in the background.
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on June 21, 2019, 06:41:49 pm
Can anyone check on iPhone of it does the same - I’m sure it worked fine but I can check again.

I’ve posted on SD forum but so far they’re not being helpful.
http://forums.skydemon.aero/Topic28784.aspx#28794


There’s a setting in IOS called “Background App Refresh” which looks like it should “solve” the issues but SD doesn’t shown up as an app you can select for it in the settings pages.
Title: Re: Losing connection with switching apps in iOS
Post by: Grem on June 30, 2019, 11:44:34 am
SD shows up as an app in my iPad mini 3 settings list, but even with Location services set to "always", SD still loses the PA Wifi input when I switch to PA radar. My iPad doesn't have an internal GPS and I wonder whether choosing "Use PilotAware" rather than "Use Location Services" on the SD menu that appears when I press "Go Flying"  means that SD doesn't look for a signal from "Location Services"?  I have a GNS2000 standalone GPS so next time I'll try connecting that via Bluetooth as well as the PA Wifi, and see what happens.

Title: Re: Losing connection with switching apps in iOS
Post by: marioair on June 30, 2019, 11:59:55 am
I have progressed this with SD support and they’ve stated that because the iPad connects to PaW over WiFi they cannot do anything about it (WiFi Connection killed by IOS when in background mode)

So ball back in PaW court to look for a workaround?

http://forums.skydemon.aero/FindPost28794.aspx
Title: Re: Losing connection with switching apps in iOS
Post by: brinzlee on June 30, 2019, 12:57:18 pm
The answer is not to minimize SkyDemon.....then it won't happen.....Most people will always keep this app running primary....
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on June 30, 2019, 01:24:03 pm
Yes.
But fairly annoying problem when it does happen. In particular I fly with other IFR related apps too!
Title: Re: Losing connection with switching apps in iOS
Post by: Paul_Sengupta on July 01, 2019, 01:30:19 am
Get another tablet and run them side by side...
Title: Re: Losing connection with switching apps in iOS
Post by: Paul_Sengupta on July 01, 2019, 01:31:57 am
So ball back in PaW court to look for a workaround?

If Sky Demon can't stop the iPad switching off the Wifi to the app when it's in the background, I'm pretty sure that PAW, running on a completely separate device, won't be able to!
Title: Re: Losing connection with switching apps in iOS
Post by: Mig29fuk on July 01, 2019, 06:54:42 am
I may be particularly thick this morning, probably grumpy too but....
I dont understand what is the relevance of IFR Apps being in the company of Pilot Aware and Skydemon, both of which I thought were VFR aids?
Regards
Gerry
Title: Re: Losing connection with switching apps in iOS
Post by: Ian Melville on July 01, 2019, 07:01:33 am
I can't make it that easy for you :-)

Ipad mini 4
iOS 12.3.1
SD 3.12.6.183

I've tried it on iPhone 6s, iOs 12.2 and it seems fine.
I have tried it on my iPhone Mini 4
IOS 12.3.1
SD 3.12.7.187

and iPhone 8
IOS 12.30.1
SD 3.12.7.187

I get the same as you report on both devices, but the time out period seems to be variable.

This issue is nothing to do with PilotAware, but is between Apple and SkyDemon. The ball is not in the PAW court to play with.

I can think of only one valid scenario you would want to switch away from SD for 5 minutes, if using the PAW Radar? If that is the case I would suggest using your iPhone for the PAW Radar and iPad for SD. Running two navigation tools at the same time? Why?

Quote
In particular I fly with other IFR related apps too!
SD isn't an IFR app, not that that has any relevance to your issue.
Title: Re: Losing connection with switching apps in iOS
Post by: exfirepro on July 01, 2019, 08:44:34 am
Hi Guys,

This isn’t a new scenario and is definitely an Apple issue. SkyDemon has always disconnected on the iPad if you change to a different app in flight. In the early days of using and developing PAW, I found that the only way to reduce the likelihood was to ‘double-click’ the Home Key when changing between apps - e.g. between SD and Safari - which I needed to do pretty much all the time during PilotAware testing. This seemed to keep SD running in the background rather than shutting it down and when it was brought back to the ‘front’ by ‘double-clicking’ the iPad Home Key and re-selecting SD, it was still running fine.

I have to say, I haven’t had any issues recently (running the Betas of both the latest PAW and SD iOS software) on an iPad Mini 2 and an iPad Mini 3 running in parallel over many hours of testing.

Regards

Peter
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on July 01, 2019, 09:07:14 am
Hi Guys,

This isn’t a new scenario and is definitely an Apple issue. SkyDemon has always disconnected on the iPad if you change to a different app in flight. In the early days of using and developing PAW, I found that the only way to reduce the likelihood was to ‘double-click’ the Home Key when changing between apps - e.g. between SD and Safari - which I needed to do pretty much all the time during PilotAware testing. This seemed to keep SD running in the background rather than shutting it down and when it was brought back to the ‘front’ by ‘double-clicking’ the iPad Home Key and re-selecting SD, it was still running fine.

I have to say, I haven’t had any issues recently (running the Betas of both the latest PAW and SD iOS software) on an iPad Mini 2 and an iPad Mini 3 running in parallel over many hours of testing.


Using this method I get 5 minutes of SD in the background before it disconnects.
I run GolzeADL weather and also have JeppMD for approach plates so have need to switch away from SD, in particular at the approach phase.
Regards

Peter
Title: Re: Losing connection with switching apps in iOS
Post by: exfirepro on July 01, 2019, 09:43:02 am

Using this method I get 5 minutes of SD in the background before it disconnects.
I run GolzeADL weather and also have JeppMD for approach plates so have need to switch away from SD, in particular at the approach phase.


OK @marioair,

During testing I would probably only have switched out of SD for a few minutes at most - usually to check something against the PAW Traffic Screen, for example, then back to SD - and do remember getting occasional disconnects, though this doesn’t change my opinion that this is primarily a case of iOS determining that the app is no longer being (actively) used and diverting resources elsewhere.

Unfortunately, Apple are very much a law unto themselves. In view of the previous SD disaster brought on by Apple’s un-announced major change in iOS12, I’m certain that even SD wouldn’t have any luck getting Apple to change their functionality.

I take it you are now running the latest 20190621 PAW software? This certainly makes PAW to SD disconnects much less likely, though it won’t have any significant effect on how Apple handles apps running in the background. It looks like limiting ‘out of SD time’ or Paul’s suggestion to run two (or more) devices in parallel is probably the only practical solution.

Regards

Peter
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on July 01, 2019, 12:38:29 pm
Upgrade to latest patch is on my to do list - excited about the MLAT/3D stuff!

I've asked Tim Dawson to consider switching to ipad's onboard Location Services if Wifi fails but he didn't want to do this. They have however agreed to put in a patch which will "auto-restart" logging when wifi is available again. Obviously that only works when app is brought to foreground
Title: Re: Losing connection with switching apps in iOS
Post by: Ian Melville on July 01, 2019, 01:25:45 pm
Also the WiFi connection does not fail. I think you mean the external GPS feed.

If, and it is a big IF, fall back to Location Services was implemented, I would expect to see flashing messages to say that the feed had failed & traffic data is not available. I might think it was just a quiet day :-\
Title: Re: Losing connection with switching apps in iOS
Post by: Vic on July 15, 2019, 02:20:40 pm
I saw this phenomenon happen to my Co-flyer last week on his Ipad though no app switching was invoved. I, however, acheived flawless connection on my Android for both legs.

On the outbound, he lost SD connection to the Rosetta for about 15 minutes, he was concentrating on flying and it finally regained connection by itself to be stable for the rest of the flight.

On the return leg, try as he might, he couldn't get his iPad to connect on 'Pilotaware' mode. Rebooted it twice, restarted WiFi etc. He finally acheived a stable connection after I suggested he switched to 'Flarm' connection mode, after which it was faultless.

His Device:

Ipad Mini 2 32GB, IOS 12.3.1
Title: Re: Losing connection with switching apps in iOS
Post by: marioair on July 15, 2019, 03:11:32 pm
I saw this phenomenon happen to my Co-flyer last week on his Ipad though no app switching was invoved. I, however, acheived flawless connection on my Android for both legs.

On the outbound, he lost SD connection to the Rosetta for about 15 minutes, he was concentrating on flying and it finally regained connection by itself to be stable for the rest of the flight.

On the return leg, try as he might, he couldn't get his iPad to connect on 'Pilotaware' mode. Rebooted it twice, restarted WiFi etc. He finally acheived a stable connection after I suggested he switched to 'Flarm' connection mode, after which it was faultless.

His Device:

Ipad Mini 2 32GB, IOS 12.3.1

this isnt the originally reported issue - sounds like you just lost the wifi connection entirely?

definitive response given on the SD support forum about switching ios apps to background Summary: it will not support a continued gps feed VIA WIFI if the app is put in background mode. Tim Dawson states this a limitation of IOS so not an issue SD can do anything about.

Title: Re: Losing connection with switching apps in iOS
Post by: Admin on July 15, 2019, 03:23:45 pm
Vic,

Is this running 20190621 ?
If so please try adjusting the setting in Configure

Device Connect Setting => PilotAware(UDP)

This still allows the FLARM connection

Thx
Lee
Title: Re: Losing connection with switching apps in iOS
Post by: Vic on July 16, 2019, 07:28:32 am
Lee

Yes, PAW is the latest version.

As I said, My Android (connected by SD to Pilotaware [UDP] mode) worked fine all day.

His Ipad (connected initially on UDP) worked fine for most of the outbound leg but  wouldn't connect to PAW for the return leg (even after several reboots of the Ipad) ..until he eventually selected Flarm as the 3rd party device in SD.

I can only assume that he switched between some apps over lunch after the outbound leg when he took the Ipad with him

Agree, this is certainly not a PAW issue but certainly something that IOS users need to be aware of.. 
Title: Re: Losing connection with switching apps in iOS
Post by: grahambaker on July 16, 2019, 08:22:42 am
Long shot, but this has caught me out once or twice, is where you are on the apron and your tablet silently connects to someone else’s PAW, because they haven’t secured their WiFi with a password. You then either successfully connect SkyDemon which you promptly lose when you get out of range of their box, or it fails to connect and you are left wondering why it doesn’t.

I think the documentation should emphasise that renaming and securing your PAW’s hotspot makes like easier for everyone, especially now that uptake is becoming widespread.