Hello, with one of my PiAware setups I was noticing only 1-3 aircraft being tracked when it should have been tracking 20+. I ended up changing out the antenna and running the setup without coax cable (the antenna sits right in my window so the coax could be removed), but the results were the same. I ordered a new USB dongle and simply swapped it out while the Raspberry Pi was running and I was tracking the expected 20+ flights again (almost reached 50 flights).
The rtl_test.exe returned two lines “lost at least 196 bytes” and “lost at least 88 bytes” and provided no further output. From what I understand, this is expected and the SDR dongle should be operational. However, when it was plugged into my Pi, it was not performing properly. Is there a way to troubleshoot further or should I toss the old USB dongle?
It looks like the rtl_test.exe runs the test at a sample rate of 2.048 MS/s. However, dump1090-fa runs at a sample rate of 2.4 Ms/s. Try to run the test at 2.4 Ms/s. On the Raspberry Pi it would be rtl_test -s 2.4e6
Edit to add: You have to have rtl-sdr installed on your RPi as abcd567 says in Option 1 of the link.
If your set up uses a USB to USB micro jumper between the SDR and RPi, it may be worth a check.
I struggled through 4 months of buggy 978, and one of the FA engineers finally got me fixed up this week.
I have been using the USB dongle plugged directly into the RPi USB port.
Since the new USB dongle fixed my PiAware site, I took another RPi I had and did a fresh install of Raspberry Pi OS. I installed rtl-sdr and ran the test.
At first I got:
Found 1 device(s):
0: â–’â–’Ńľ, , SN: Dâ–’Ńľâ–’â–’â–’â–’â–’â–’Ńľ
PuTTYUsing device 0: Generic RTL2832U
usb_open error -3
Please fix the device permissions, e.g. by installing the udev rules file rtl-sdr.rules
Failed to open rtlsdr device #0.
Then I switched the USB port and ran the test again and it looks successful like abcd567’s example thread:
Found 1 device(s):
0: Realtek, RTL2832U, SN: 00001000
Using device 0: Generic RTL2832U
Detached kernel driver
Found Rafael Micro R820T tuner
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
[R82XX] PLL not locked!
Sampling at 2048000 S/s.
No E4000 tuner found, aborting.
Reattached kernel driver
I switched the dongle back to the original USB port I had it in and ran the test a third time, it was successful again. I ended up having to re-install Raspberry Pi OS since I did the x64 version and PiAware wouldn’t install. I ran the test with the 32-bit version and got the same results where the USB dongle was not detected at first.
After this I installed PiAware and I am picking up 30+ aircraft with an antenna that is a few feet from the window. It looks like every time I restart the RPi, I will need to plug this USB dongle into another USB port for it to start working - wonder why this is, since this dongle did not use to do that and none of my other ones do.
