HOWTO: Airspy mini and Airspy R2: Piaware / dump1090-fa configuration

The Odroid requires you to know how to compile dump1090-fa and more while for the RPi (if you take 32 bit) its a simple apt install.
That said 64 bit is faster on RPi too which means you should probably compile things anyway.
My Odroid N2+ runs Airspy mini on 12MS/s currently without ever hitting 100% cpu usage. (Thats 100% out of 600% due to 6 cores and each can go 100%.) The issue with the Odroid is its USB ports are slow. I can not run FA Blue and Airspy at 20MS/s only 12MS/s. Not that is matters much.

I have run my FA blue and Airspy at 20 MS without an issue. I am running the Airspy at 12 at the moment, just doing some temperature tests up on the mast, getting ready for a hot Australian summer. What OS are you running the N2+ with, currently here running Armbian_21.08.1_Odroidn2_bullseye_current_5.10.60.img.xz .

I am running the debian build because for some reason armbian never launched when I copied it to an SD card. This one: [OS] Debian Buster for ODROID N2 - ODROID

Just saw that @wiedehopf released 2.2 RC 30. ( 2 hours ago)

Curious what great improvements he made this time.

That was twelve days ago.

mmm must have missed that.

Screenshot 2021-10-17 om 17.07.53

the github page does say 2 hours agoā€¦it did that yesterday tooā€¦so i can understand Dutchybā€™s confusion.

Iā€™m just going by this post:

Maybe @wiedehopf sneaked in one update and forgot to increment the number.
I already have 30 from a while back. Updating it from github leaves it at the same 30.

There is nothing to change :stuck_out_tongue_winking_eye:

I sometimes test something using the repo ā€¦ 2.2-RC30 is unchanged.

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Canā€™t be far from a final 2.2 release now?

Installed your image still canā€™t run FA Blue + Airspy Mini at 20MS/s

You tried using -p bit packing option in the config? Helps with USB bandwidth. Iā€™ve been running Airspy @ 20 MSPS today with FA Orange stick with UAT. Only works with -p option set on Pi 4, preamble of 35 is stable. Only problem is that MLAT wonā€™t synchronize. Otherwise it runs fine. Just wanted to try 20 MSPS for a while with @caius heatmap scripts. (I get more UAT aircraft and messages than MLAT so no biggy losing MLAT for a while).

  1. You might not have anyone doing UAT around you to get that MLAT working. You need at least 4 stations.
  2. Even if there were 4 of them, UAT doesnā€™t need MLAT because it has the position encoded. There is no other ā€œS-Modeā€ sent on that 978MHz frequency, without position encoded like itā€™s on 1090MHz, so thereā€™s nothing that needs to be triangulated by MLAT.

Yes, I know. Iā€™ve been running Airspy at 12 MSPS with MLAT synchronized to 400+/- stations every day for almost 1.5 years. This on my Pi 4 that also has an Orange FA stick working fine with 20 to 100 UAT aircraft per day.

For todayā€™s test, I just want to try running Airspy at 20 MSPS without disabling dump978-fa. It works great other than no MLAT synchronization. If I disable dump978-fa, then MLAT starts working at 20 MSPS again.

Iā€™m just testing for collection of data to compare 12 MSPS vs 20 MSPS heatmaps. Since I get more UAT aircraft and especially positions than MLAT, Iā€™d rather lose the MLAT metrics than the UAT metrics.

Plus, wonā€™t MLAT just show up in ā€œOtherā€ aircraft metrics when synchronization isnā€™t working?

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Sorry, not sure then. Re MLAT, what are you running readsb or Flightaware 1090? I have recently tried and now swapped over to readsb. I noted, although I had logged my location as per the installation instructions on readsb, my fligtaware data indicated that my MLAT was not syncing and the cause was location not logged in FA. So I went into my FA location details, edited those details (they were all there) and saved. The MLAT instantly come back in sync. Not sure what caused the problem but that was the simple fix. :slight_smile:

I ran into this issue running an Airspy R2 and FA Orange dongle on the same deviceā€“any sample rate higher than 12 MS/s prevented MLAT synchronizing (on more than just FA) regardless of the -p option. My solution was a second RPi4 running the UAT dongle connected via ethernet and running a dynamic socat tunnel for the UAT port.

Ah, I never tried to do that. I have an older Pi3 separated for UAT.

that is my setup as well. I was not able to sync at MSPS 20 with both airspy and dump978 running on the same pi 4. In the end I decided that a separate pi 3 for 978 was the way to go. Tar1090 can see both at the same time on the pi 4. I have not found a solution for running 20/24 MSPS running on 1 pi.
BTW this 2-pi setup (with everything visible on the pi 4) works perfectly well and I am happy with it.

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So ā€¦ iā€™ve done some very very minor changes to the digital filters for 20 MSPS and a minor change to the digital filters for 24 MSPS.

Itā€™s hard to say definitively if itā€™s an improvement or not, so if you feel like testing something you can record a sample as described in the airspy-conf readme on github and then decode it using both versions (rc30 and rc30-test).

Test binary is available like this:

sudo bash -c "$(wget -O - https://raw.githubusercontent.com/wiedehopf/airspy-conf/master/test-binary.sh)"

The regular RC30 remains available via the regular update-binary.sh script.

Donā€™t expect anything ground breaking.
And even if it works well for you that doesnā€™t mean these changes are gonna stay if it works significantly worse for someone else.
The filters are very tricky business :slight_smile:

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