PAW failure

[RobertPBham]

Hi there,

As probably known from a previous thread, I have experienced PAW failure in flight - normally after 30 minutes or so. I was kindly supplied with a replacement WIFI dongle and ADSB dongle and antennae. This appeared to work for 40 minutes or so of circuit flights the other day.

However, this weekend I flew to Cambridge and back - on the flight to Cambridge the PAW failed approximately 20-30 minutes in to the flight - SkyDemon disconnected and the PAW WIFI network was not visible on my phone - I switched to location services and everything was fine. The PAW was located on the 'dash'.

On the flight home, I moved the PAW to the rear passenger seats thinking it may be a heat issue. Again, 20-30 minutes in to the flight, the PAW failed with no PAW network available - switching to location services resolved the issue within Sky Demon.

What are the best troubleshooting mechanisms I have available - it appears that running PAW in my apartment for an hour or so doesn't cause any issues and the unit doesn't fail. What do I need to turn on logging wise to work out what may be happening?

Thanks
Rob

[AlanG]

Hi Robert

The first question that springs to my mind is:- What, if any, difference is there in the way you are powering the unit in the aircraft and at home.  More problems are caused by voltage drop due to insufficient or inefficient power supply to the PAW than any other single cause.

Alan

[JCurtis]

Connect to your PAW and look at the tracks screen, does it show multiple tracks starting around when the problem started.  It starts a new track on a reboot so a handy way to see if its rebooting, a single track file for the whole time you had it powered on would indicate it stays up but the voltage may be too low for the WiFi dongle to work properly.

[RobertPBham]

Thanks both for the replies.

To start off, there is no difference in my home setup to the aircraft setup - I have a self contained PAW pack which I carry with me.

I have connected to the PAW and on 02/12/17, I do see two track files - a new one starts at 11:58 - this is three minutes after I switched to location services on my iPhone. The journey back (03/12/17) only has one track file. It does look as if the unit is rebooting - especially based on the data from the 02/12/17.

I have a Zendure power pack which was fully charged before the flight and is still showing full charge now.

Thanks
Rob

[RobertPBham]

After thinking about what Alan put with regards to whats different between home and the aircraft the only thing I could put my finger on was vibration...

so, I took the PAW apart and found that the bridge (I believe that's what it is - the circuit board that has PilotAware printed on it) was more than half way off the connectors to the main board. I could easily see each one of the pins!

So, I've reassembled it all with the connectors secured and I will see how everything goes - I'm hoping to fly soon so will report at that point. Hopefully the above would suggest the reason for a reboot.

What logging needs to be turned on to gather all system data for troubleshooting - I see lots of options under the Configure menu, but don't know what any of them mean:
Log Interface Messages
 replay  tfc  trp  adsb  nmea  nav  trx  bmp

Thanks
Rob

[RobertPBham]

And not to keep spamming the thread, but I think I know how it's happened as well.

The case I bought isn't big enough for the PAW and the WIFI antenna within it - hence I attach the WIFI antenna when I use the PAW and have it resting on the edge of the case - the PAW at a slight angle to achieve this - hence I think it is putting pressure on the bridge and basically pulling it away from the main board - as you can see in the attached picture - I think the vibration is causing this.

So, I guess my next question is, can I but an antenna similar to the ADSB one - where I can run a connector from the bridge connector and have it stand up in the case so there is no pressure on the board?

Thanks
Rob

[RobertPBham]

Would this be the correct sort of thing?

https://www.ebay.co.uk/itm/3M-SMA-WiFi-Router-Antenna-Extension-Cable-Wire-Lead-Connector-Magnetic-Base/263216796636?hash=item3d48f193dc:g:Mf0AAOSwk~NZwOw3

I assume I could just attach my current antenna then.

[Ian Melville]

If you hard case is correctly screw together and the connector hole in the end plate is a small as possible, there will be no leverage on the bridge board by your soft case arrangement. I would be more concerned about your power feed, which has a forced tight bend.

I would also try a different power supply. Zendure is a new name to me. If you want confirmation of a reboot, check the home page before you shut the PAW down. Does the run time match with the time you turned it on?

[Deker]

Hi Robert,

That particular mag base is for wifi and used RP (reverse polarity) connectors- centre pin opposite to what it should be.
I've been using a Zendure (A3 10,000mah) of over 12 months with out any problems, but if you can borrow another to at at least eliminate one possibility.

ATB
Deker

[AlanG]

Hi Robert

As Ian has alluded to, this is not a power bank that has been tried and tested with PAW up to now and this sentence in a review I have just read worries me slightly.  :-

"Also new here is Zen+ power-management technology. Rather than a straight 5W/5W split between the two USB outputs, the Zendure can cleverly recognise the devices attached and supply an optimum amount of power for charging them."

This "intelligent Charging" could be the culprit as the demand from PAW is constantly changing depending on the differing amount of information it requires to process, whereas for charging phones etc it will be a fairly steady current I would expect.  I suspect that a sudden demand for power that the power bank is not expecting may cause a brown-out and therefore a possible reboot of the RPi.
I may have imagined this, but i believe there has been some discussion  around this type of intelligent power bank idea in the past, but I can't find it just now.

The recommended power banks are the Anker variety but having said that I personally initially used two EC Technology 22400mah packs with no problems.  I now use the Anker Powerdrive 5 as I have now permanently mounted my PAW.

A bit of soft non conductive material stuck inside the case could help to keep the bridge in situ. 

Regards
alan

[RobertPBham]

Thanks for the replies all!

I’ve been using the Zendure for well over 18 months without issue but that certainly doesn’t mean it hasn’t developed an issue.

I’ll do some more testing now I’ve reseated the bridge and go from there. I’ll update as soon as I get to fly next!

Thanks
Rob

[RobertPBham]

Just to update the information in this thread - had my first flight today (Christmas is always busy). After an hour and twenty minute flight in very turbulent conditions there was absolutely no drop outs of the PAW.

I think I had three separate issues that all needed resolving to fix my issues - melted WIFI dongle and ADSB dongle and PAW bridge physically disconnecting from the Pi!

I’ll continue to monitor but think it’s sorted! :-)

I will find a way of ‘wedging’ the bridge and Pi together in the case to cover that one off!

Thanks
Rob

[exfirepro]

Robert,

While rebuilding a ‘Classic’ recently for someone after similar problems to yours, the possibility of the Bridge loosening in flight due to vibration arose. I ‘fixed’ it by inserting one of the spongy foam packers from the PAW delivery boxes carefully along the line of the GPIO pins on the top edge of the Bridge. When the case is closed and screwed shut this applies just enough pressure to prevent any undue movement. I used the same trick with the one in my own aircraft about 2 years ago and have never had any problems.

Regards

Peter

[rogellis]

Another very different possibility.

If there is any PAW wifi interruption at all, my tablet will immediately lock on to its favourite wifi, which could be an iPhone hotspot in a passenger’s pocket.   When this happens you don’t get an error message, because the Nav software still has a (different) wifi connection.  It may, much later say “not received data for some time”.  The PAW compas rose will not give a wifi error message either, the ‘compass’ display remains but is blank and shows no conflicting aircraft.

See my thread on error messaging....
http://forum.pilotaware.com/index.php/topic,1117.0.html

R