using Avare with Xplane11

[dami...@gmail.com]

Hello.

Thank you for the wonderful app.  I have been using Avare with FSX and Prepar3d for a couple of years without problem via Xconn.  Works excellent.  I switched to Xplane11 and it has built in support for external tablet gps like Avare.  It connects to Avare but the update rate is painfully slow to the point that it makes it unusable.  The lag is anywhere from several seconds to up to 30 seconds between position updates. 

Never had this issue with fsx/p3d so I assumed it is an Xplane11 issue, especially since it is beta.  But I can connect another external android gps app and it gets regular constant udp updates from Xplane without delay or hesitation. 

Somewhere between Avare and Xplane11 there is a communication delay or breakdown.  

Any thoughts or ideas how to remedy or work around this so I can use Avare with Xplane11? 

Thanks!

[Alex Berryman]

I've started to notice intermittent issues with slow/missing GPS updates from X-Plane 11 as well. 

Using Wireshark I can see that XP11 is outputting UDP packets at a constant rate, but every couple of minutes the logging in the Avare I/O will stop updating and Avare will say "No GPS Signal."

Even if I toggle the "Listen" box in Avare I/O to restart the process it can take 30 seconds or more before updates start flowing again. I haven't had any issues like this using a Stratux ADS-B receiver in a real plane or with FSX either.

I'm starting to look into this issue now, and I'll let you know what I find. Let me know if you're still having this issue, or if you already found a solution.

[Alex Berryman]

I think the buffer for incoming messages from X-Plane is too small/simple to find the GPS position data in a sea of AHRS info being sent by XP11.  

X-Plane 11 is sending out two types of messages: XGPS and XATT. The XGPS message is what Avare is looking for to update your position on the map, and the XATT message is attitude info (pitch, roll, yaw) that is discarded by the current Avare I/O code.

The issue is that the "useless" XATT (Green lines in graphs) messages outnumber the XGPS (Blue line) messages 10:1 packets/second, or 1000:100 bytes/second. The current Avare I/O code only has a buffer 1000 bytes, and checks it every second. My guess is that the inconsistencies that we are experiencing is due to the fact that most of the times that Avare I/O checks the buffer it is seeing a "useless" XATT message instead of the XGPS message that it needs.

With the current code it seems like getting a XGPS message from X-Plane comes down to luck. I'm still working out the best way to filter out the XATT messages so that Avare I/O doesn't miss any XGPS messages. I think the answer might lie somewhere in the 'BufferProcessor()' like they use for Wifi Connections.

[Alex Berryman]

It was a buffer issue, just not how I originally thought though. I submitted a pull request with my fix to on GitHub: https://github.com/apps4av/avarehelper/pull/18

The code was just trying to parse the entire buffer, but the XGPS messages are only ~93 bytes, and the XATT messages were ~115 bytes. When an XGPS message was placed in the buffer after a XATT message there remaining bytes were still being read. 

This means that instead of speed being correctly parsed as "105.8772", it would have garbage precision added on like "105.87725578", or in the worse case which led to us noticing the missing GPS updates "105.87725.78" where the extra decimal place caused the parsing to fail. Once you got enough updates with the that extra decimal point Avare would show the "No GPS Signal" error.

My fix uses the length of the last UDP message to correctly create an input string only using the valid XGPS data.

[David Chasteen]

Alex,

Thanks for troubleshooting this. Hate to revive a zombie thread, but I'm having exactly this same problem with both XP11 and XP10. Still having the intermittent connection/disconnection. I can go minutes without it working, then it'll pop back up. Annoying.

I'm running Avare 7.8.6 and AvAddon 4.0.4

Is anyone else having this issue or is it just me?

I'm running on a Kindle Fire HD8.

[fly...@yahoo.com]

Hi David and everyone.

I've seen that problem with XP10 but not with XP11, yet, but I did not test it for long periods of time.

If you can, post the length of time after which this occurs, how did you set up your XP set up output, Port, IP,  what your PC specs are, what your Frame rate in XP is...

The reason for all this info request is to better analyze and find the possible reason for this lapse. I know that XP, in general, will eliminate tasks that they consider lower priority in order to maintain a smooth / fluid operation. In some cases, if they cannot maintain 20FPS or higher, they will actually slow the real time down to give you that perception, another way to visualize this is to shoot an ILS, and time it, what may be in real time 3 min. in the sim could be 3.5 min. or a flight that should take 1 hr. in real time may take 1.2 hrs. in the sim.

I've looked at the request from Alex, and implemented in one of the the versions for my own use, and it may be worth looking at it again, but I think that it can add some more delays, overall, in the app. I will try to touch bases with Z, or he may be reading this and see what he thinks. TV

[Matthew Orlando]

For anyone still having this issue I had two problems. First, the PR listed below was merged a couple years ago, but the Avare I/O plugin hasn't been released to Google Play since 2017. Without this fix the GPS connection is very unreliable even on a good network.

But I was still having disconnection issues even after building the latest version myself. It turned out that the WiFi router in my cable modem (Cox Communications) was dropping UDP packets like mad. when I switched my tablet to another WAP on the same network everything started working great.

[John Wiley]

> the Avare I/O plugin hasn't been released to Google Play since 2017

Thanks for bringing this up, Matthew. I can't check at the moment, but it seems likely the latest APK is listed on the same server as Avare for the Manual Install process (sideloading) outlined on the website. If not, maybe someone on the Dev Team could set that up so that it updates there automatically as Avare seems to do?

[Matthew Orlando]

I looked for something like that (apk files) on the main site before but didn't find it. After your message, I found it after a bit of digging: http://www.apps4av.org/share/?O=D

Unfortunately, the releases there seem to match the ones on google play. The last AvAddon.apk is from 2017

[David Durst]

I've been using this setup for some time with XP11 and after its working for some time in flight it stops and then catches up and starts working again. I really want to stick with Avare but it seems this is not going to be resolved anytime soon.  (been flying and using this for a few years with the same stopping and starting of the data from XP to the GPS. I can use MSFS2020 with no issues at all for hours at a time. I've tried a few other GPS apps and they all work fine as well, this issue seems to only affect XP and Avare Exdternal I/0 App from what I can tell. 

This 100% is not a PC issue or WiFi issue at least in my case as mentioned above I can use other programs with Avare and they work fine, I can use other GPS software with XP 11 and it seems to work with no issues, its only XP11 and Avare IO External App combination that causes the issue.

[t v]

>>I've been using this setup for some time with XP11 and after its working for some time in flight it stops and then catches up and starts working again. <<

Hi.

If you post your AOS, Avare and IO vers, you may get some better help, but as you observed, and I can confirm it, in XP 11 55RC1 and both  Avare 803 with IO2.0  and 9.02 and 4.04 I get the same intermittent updates, it works better with the older versions, but I cannot test anything newer. Things have gotten worse since the code was modified to internal IO and likely to get worse as Gobble will impose more restrictions in the future. I ignore the update problems and I mostly interested in the final Result / Track for how I use it.

As to the FSXX / 2020 for the first time in over 40 years of aviation and simming I do Not have a new sim  release on my system, It's completely useless to me as a tool.

You may want to try some older versions combinations, get some here: http://www.apps4av.org/share/?O=D but I do not think that it will help much. Going to the internal IO, at the request of very few, created other problems.

Make sure you get good FPS in the XP, at least 50 FPS and select GPS/Use all available sources, and see if it helps. TV

[David Durst]

Thanks for the suggestions, however this issue is not caused by my setup in the software of XP11, the issue is 100% the I/O external connector that is causing this issue.

I've found two other software titles that so far are working perfectly with XP11 (and MSFS2020) so more than likely I'll move on to one of them and just remove Avare from the picture.