FlightAware Discussions

Feed cuts out on a regular basis

As you can see here, my system stops feeding every now and then during the day:

I’m not sure what causes it. I changed the old 1A phone charger with a beefier 3A supply, that seemed to help but for just 1 day (last Monday, the 26th).

I’m not sure what logs to check, but I’ve looked at piaware.log which contains this:

Jul 29 08:52:33 piaware piaware[668]: mlat-client(1286): Receiver status: connected
Jul 29 08:52:33 piaware piaware[668]: mlat-client(1286): Server status:   not synchronized with any nearby receivers
Jul 29 08:52:33 piaware piaware[668]: mlat-client(1286): Receiver:   52.6 msg/s received       13.2 msg/s processed (25%)
Jul 29 08:52:33 piaware piaware[668]: mlat-client(1286): Server:      0.0 kB/s from server    0.0kB/s TCP to server     0.1kB/s UDP to server
Jul 29 08:52:33 piaware piaware[668]: mlat-client(1286): Results:  9.5 positions/minute
Jul 29 08:52:33 piaware piaware[668]: mlat-client(1286): Aircraft: 21 of 21 Mode S, 1 of 1 ADS-B used
Jul 29 08:56:11 piaware piaware[668]: 1104564 msgs recv'd from dump1090-fa (171 in last 5m); 1104549 msgs sent to FlightAware
Jul 29 09:01:11 piaware piaware[668]: 1104679 msgs recv'd from dump1090-fa (115 in last 5m); 1104664 msgs sent to FlightAware
Jul 29 09:06:11 piaware piaware[668]: 1104852 msgs recv'd from dump1090-fa (173 in last 5m); 1104837 msgs sent to FlightAware
Jul 29 09:07:34 piaware piaware[668]: mlat-client(1286): Receiver status: connected
Jul 29 09:07:34 piaware piaware[668]: mlat-client(1286): Server status:   not synchronized with any nearby receivers
Jul 29 09:07:34 piaware piaware[668]: mlat-client(1286): Receiver:    2.9 msg/s received        2.2 msg/s processed (75%)
Jul 29 09:07:34 piaware piaware[668]: mlat-client(1286): Server:      0.0 kB/s from server    0.0kB/s TCP to server     0.0kB/s UDP to server
Jul 29 09:07:34 piaware piaware[668]: mlat-client(1286): Aircraft: 1 of 1 Mode S, 0 of 0 ADS-B used
Jul 29 09:09:29 piaware piaware[668]: mlat-client(1286): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Jul 29 09:09:29 piaware piaware[668]: mlat-client(1286): Input connected to localhost:30005
Jul 29 09:09:29 piaware piaware[668]: mlat-client(1286): Input format changed to BEAST, 12MHz clock
Jul 29 09:11:11 piaware piaware[668]: 1104861 msgs recv'd from dump1090-fa (9 in last 5m); 1104846 msgs sent to FlightAware
Jul 29 09:16:11 piaware piaware[668]: 1104903 msgs recv'd from dump1090-fa (42 in last 5m); 1104888 msgs sent to FlightAware
Jul 29 09:17:56 piaware piaware[668]: mlat-client(1286): Disconnecting from localhost:30005: No data (not even keepalives) received for 150 seconds
Jul 29 09:17:56 piaware piaware[668]: mlat-client(1286): Input connected to localhost:30005
Jul 29 09:17:56 piaware piaware[668]: mlat-client(1286): Input format changed to BEAST, 12MHz clock

Is that still a power supply issue or something else? Are there any other logs to check?
No planes visible on my own Skyaware page either.

Graphs can help: GitHub - wiedehopf/graphs1090: Graphs for dump1090 (based on dump1090-tools by mutability)

But it definitely looks like a reception issue from log.

Aircraft: 1 of 1 Mode S, 0 of 0 ADS-B used

So you can try replacing the SDR, check the coax for water ingress or lose connections.

Considering that replacing the power supply improved things for a bit i’d guess the SDR is on its way out.
But can’t say for sure, hard to test which part of the reception chain is failing.

I have those. Any particular graph that could tell me/us something?

Connections inside seems fine, can’t tell the single one outside (on roof). But connections have never failed me in all the years I’ve been running the system.

Only for a day.

The weirdest thing is, it only happens during the day, always somewhere between 12 and 8 in the afternoon. Never in the morning or at night. And as you can see, it sometimes comes back for something in between dropping the feed.

Are there any (other) logs I could check?

EDIT: vcgencmd get_throttled result is throttled=0x0.
So the power supply under-voltage problem.

EDIT #2: And the feed is gone again…and now back again…

EDIT #3: When looking at the Skyaware page, reception seems go up and down, up and down.
One moment I have great reception and then almost all planes disappear. And then they appear again after a while…

If I can receive aircraft from very far away at times, I don’t think a physical problem (antenna, connection) is the issue right? Because then I couldn’t receive those aircraft.

the first graph and the signal graph … post those for the last 2 weeks and the last 24h.

Yeah that would be a fair conclusion.
Intermittent issue.

Here they are:



ADS-B Signal Level 2 weken
ADS-B Signal Level 24 uur

It just occurred to me, I’ve this old cheap DVB-T stick laying around somewhere. Maybe I have the right connectors to use that, I’ve problem is solved = FA stick is dead.
If problem is not solved = something else.

Heat? (Either overheating hardware, or possibly even thermal expansion in connectors if you have a marginal connection somewhere)

Or it could be an interfering signal from equipment that’s not always on. There was someone who had problems with messages cutting in and out seemingly at random, and it was interference from some kind of wireless-TV-transmitter they had.

Don’t think it’s the heat. We have a cold summer here (last few years if was HOT!) and sometime ago I installed the fan that was included with the RPi case. (that lowered the max core temp with ~15 degrees)

It’s definitely not hot in the attic.

Luckily, I had the right adapter cable and installed the old DVB-T stick. (This one)
I have reception now, I’ll check if it continues.

By the way; after not having used that dongle in years; that blue plastic casing is disgusting. :confounded:

Well, replacing the SDR didn’t help…

Can you rather show the graphs1090?

Did you ever get any reception with that SDR?
Could also be that the USB chip on the pi is dying …

Ceck the dump1090-fa log, it’s often not very useful in these cases but doesn’t hurt to check:
Debug commands · wiedehopf/adsb-wiki Wiki · GitHub

From the last 24 hours (since replacing the FA stick with the old DVB-T stick?
If so; here (I replaced the FA stick with the old DVB-T stick last night (Saturday around 22:00):


ADS-B Signal Level 24 uur DVB-T

As you can see, I did until this morning.

No such file or directory.

Something else though; now the system is telling me undervoltage and throttling has occured.

/opt/vc/bin/vcgencmd get_throttled

gives me:

throttled=0x50000

I did not get these undervoltage/throttling errors before. I didn’t get them in the past, not yesterday but only now. Guess both 5V phone chargers (1A and 3A) have problems, so will order the official RPi power supply.

Hopefully that will solve the problem…

IIRC, they sometimes do supply less then 5V, especially if they have to supply more A. Not problem while charging a device, but the Pi’s want their 5V.

And often they are not made for 24/7 duty, so they do not last that long.

Not what i linked, let me be more clear:

sudo journalctl --no-pager -u dump1090-fa

But yeah if you get undervoltage messages … get a proper power supply.

Maybe I’ve been lucky then; the HTC 1A phone charger had ran the setup for almost 5 years straight without problems. :open_mouth:

Ah, right. Did that and nothing unusual there.

The RPi power supply has been ordered and should arrive this Tuesday. We’ll see…

Actually, I am impressed, saw in another thread that it powered a Pi3, the FA stick and the rtl-sdr adsb-preamp…

It did. And as it turned out; that old phone charger isn’t faulty; I just replaced the other (3A) phone charger with the official RPi power supply and it was working for some minutes but down again.

So to me it comes down to either:

  • Raspberry Pi (hardware failure, doub it, that would cause all sorts of problems I don’t have, except maybe some sort of USB hardware failure)
  • FA orange stick (hardware failure)
  • bias tee injector (hardware failure; power LED is on though)
  • LNA
  • Software issue
  • Some weird external influence on the reception.
    (I’m currently doing this test: Do I Need A Filter?)

I think I have an old 1st-gen RPi model B somewhere; I replaced it with the RPi 3B+ since the old RPi couldn’t handle the increased load, but I may be able to swap the RPi 3 with the old RPi and see if the RPi3 is failing.

Could it be wlan network connectivity? Not sure how that would affect the stats collection, but it could explain why no data is send to FA and you can not access Skyaware, and why it happens during the day (neighbors streaming Netflix etc).

Better try this one. It covers full frequency range of Dongle, and is pretty fast.

Spektrum - How-to Speedily Scan RF Noise in band 24MHz ~ 1800MHz

The results of scans are below:

The scan 1 shows RF noise picked by antenna and processed without any filter , The scans 2 & 3 were done with filters, and show how filters remove this noise.

Scan 1 of 3 - FA Antenna + Generic DVB-T (no internal or external filter)

Thumb-Generic DVB-T

CLICK ON IMAGE TO SEE LARGER SIZE

Scan 2 of 3 - FA Antenna + ProStick Plus (Only Internal filter of ProStick Plus. No External filter)

image
CLICK ON IMAGE TO SEE LARGER SIZE

Scan 3 of 3 - FA Antenna + ProStick Plus (with internal filter) + External Filter (FA Light Blue)

imageimage
CLICK ON IMAGE TO SEE LARGER SIZE

There’s no network problems. I can access the Pi just fine, including Skyaware. It’s just not receiving/displaying any aircraft, or very few. And it comes and goes.

Thanks, will look at it tomorrow.

graphs1090 doesn’t depend on the pi having network connectivity and it’s showing the gaps.

Yeah you could absolutely try the old pi.
Could very well be MLAT won’t work or you lose some data.

But it should show consistent reception even if it’w worse than possible reception due to insufficient CPU.
The sd-card should work i believe but i’m not 100%.

Will check some more things tomorrow, maybe indeed the old RPi, the old DVB-T stick and that full frequence range test thing.

As long I don’t lose my streak! :wink: 1811 days and counting. :open_mouth:

By the way; mega thanks to you folks for helping me out so far!