Just a quick question, I am running a Pi 4 (4gb) with a Airspy Mini, running VRS and feeding all the usual sites, would I see any difference if I set up another Pi and moved everything over to that leaving the Airspy on it’s own running on the Pi 4? Thanks
no. (20 charsssssssssssssssssssssssssss)
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hey folks, I’m running airspy r2 with dump1090-fa and trying to get airspy-related graphs (under graphs1090) working. however, it looks like the problem is that airspy doesn’t create/populate JSON file in /run folder.
the configuration is there:
STATS= -S /run/airspy_adsb/stats.json
and it looks like the permissions are also ok (airspy process running with root).
any ideas why that could be?
raspberry image, debian 10, rpi 4b.
thanks!
Your electricity usage would go up but that’s about it.
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Does the directory exist? Does the file exist?
Have you used the script to set it up?
https://github.com/wiedehopf/airspy-conf
Rerun the install, then redo your airspy settings.
You might also need to restart graphs1090 so the graphs are shown.
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Thanks everyone, I just had one spare but won’t bother if it won’t make any difference 
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looks like indeed it was an installation problem, the issue has been fixed after reinstall - thanks!
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I’m running Airspy mini + triple filter low nf design made by rtl-sdr.com on RPI4b for more than a year now and so far was enjoying the performance compared to FA-SDR dongle and filter I had before.
Recently I’ve upgraded to airspy_adsb v2.2-RC30 and noticed some improvements in reception and numbers, but also some elevated CPU utilization on the same RPI4b system - some data is available with the link following: http://pi.evbcloud.com:8080/graphs1090/
I’ve checked the recommendations here on the forum and figured out that the optimal parameters for airspy in my setup are the following:
GAIN=auto (looks like it’s between 13 and 14 now and previously I was using a static number of 17)
OPTIONS= -v -t 90 -f 1 -w 5 -P 8 -e 10.3 -C 85 -E 60 -b
SAMPLE_RATE= 12
The receiver is located not far from Schiphol airport (EHAM), that’s why I have some strong signals around.
Not sure if there any room for further optimization is available, but any ideas/recommendations are very welcome!
If you are using a pi4, then try using a sample rate of 20MHz instead of 12. You will see a bump in messages received and maybe a small increase in the number of aircraft. If you are using -C to set a cpu target then -e and -E are superfluous, but it doesn’t do any harm to have them.
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How does the Auto gain compare to the old fixed value in RC30?
it was v1.85 with a statically defined gain level before. after moving to RC30 I’ve changed the settings to Auto and it looks like it gets more data overall (compared to 1.85), but can’t say what was the trigger.
thanks for the clarification, I’ve removed some parameters and now running the software with the following keys:
OPTIONS= -v -t 90 -f 1 -w 5 -P 8 -C 90 -b
also yesterday around 22.40 (CET, UTC+2) I changed the sample rate from 12 to 20 but honestly, I don’t see a big difference in the number of AC or ADSB-rate itself. however, the CPU utilization is sky-high on the same setup (you can check the graphs: http://pi.evbcloud.com:8080/graphs1090/)
Yeah the difference is not huge, but it is noticeable - you can see in your graphs the busy period is immediately above the last week’s average and the maximum for that time. I did an analysis of it a while back:
Your cpu is fine either way - the graph is showing total load across 4 cores so it hovering about 180-200% means it’s only using half the capacity of the pi 4. Unless you are having specific problems with temperature or something else then there’s no harm leaving it. The power consumption won’t be much different either.
I should probably try re-running some of those previous tests now that traffic has increased significantly.
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If the temperature is higher, the power consumption is higher
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Indeed, but note the qualifier ‘much’. The pi 4 draws about 4.5W with one core at max and about 5W with 2 cores maxed, and about 6W when flat out with all cores. Doesn’t really seem worth quibbling over 0.5W.
In case someone is wondering if it has to be a Raspberry PI 4 - no.
Because of a rearrangement of my Jetvision device i temporarily use the Airspy connected to one of my spare Raspberries (which is a 3B).
Works without issues, however you need to keep an eye on the temperatures
I am using low-key setting to avoid overheating. Device is outside with no additional option of cooling.
OPTIONS= -v -t 90 -f 1 -w 5 -P 4 -C 30
Tried higher -C and -e/E values which increases CPU and temperature to above FA warning level (approx. 70°C)
Just in case somebody is interested:
That’s the power graph of my current Raspberry 3, connected to a smart power jack capable showing the electric current.
First 20 Minutes the blue FA dongle was used, then i switched to the Airspy with several value changes over time which increased/decreased power consumption (and of course temperature)
Before that i had a Raspberry 4 connected, This device used 40% more compared to a Raspberry 3 and 50% more than the Jetvision Airsquitter with the hardware decoder.
After just setting my Airspy mini up on a Pi4 I decided to try a sample rate of 20.
Message rate dropped by about 200 to 300. There was maybe a small dip in total number of aircraft (but that may have just been time of day differences). However I also lost MLAT.
I know the config file says that using 20 for a mini isn’t supported, but thought others here are using it.
Anyway, changed it back to 12 now.
P.S. Options are currently “OPTIONS= -v -t 90 -f 1 -w 5 -P 8 -C 90 -E 60”
I use 20 MHz with a mini and have never had an issue with it. It’s had no extra heat sink and even when we had ambient outside temperatures of 40C last week (which means the loft it’s in was probably 10 degrees hotter) it didn’t have any problems.
I’d suggest checking the system log while it’s running in 20MHz to see if you are getting any dropped samples - that will mess with MLAT sync and hurt performance. Also check that the power supply you are using is adequate and that the pi isn’t throttling.
