The dump1090-fa is automatically started at boot/power up, and is using the dongle.
When you gave command dump1090-fa, it started another instance of dump10o0-fa, which could not use the dongle as it was already in use by the first instance of dump1090-fa. As a result it gave an error message: rtlsdr: error opening the RTLSDR device: Device or resource busy
Why you gave the command dump1090-fa?
If you wanted to start dump1090-fa, then there is no need to do so as it is already started at boot and running in background.
If you gave this command to check status of dump1090-fa, then you have to give following command sudo systemctl status dump1090-fa
If you gave this command to restart dump1090-fa, then the correct command is: sudo systemctl restart dump1090-fa
If it’s feeding data then dump1090-fa must be running fine. (Or there are just no planes in your view)
Check these if there are any errors with the USB device: journalctl | grep dump1090
or looking at cat /var/log/piaware.log
will be more interesting than trying to start dump1090 (which won’t work as it’s already running)
Edit: After checking your location it seems like you are boxed in by mountains a little bit and there are not too many airplanes coming by.
Imagine this: any airplanes you can’t see from where the antenna is the antenna won’t be able to see either.
The antenna will see through clouds but not through houses or mountains.
Edit2: After just checking on fr24 for planes in the area i saw some but it seems your receiver didn’t pick them up.
Most likely explanation: USB power supply is not supplying enough power, try a different one.
If you mouse-over the orange radio indicator it’ll give you a more detailed description of the problem.
Based on what I see in your stats, the warning is probably “Connected to receiver, but no recent data seen”. That means that dump1090-fa is running, but it’s not actually seeing any Mode S messages on the air.
This might be normal if you are in a particularly quiet area with no aircraft nearby, or it might indicate a problem with your antenna. It can also happen if you have a bad power supply and the rtlsdr dongle is not getting enough power to operate correctly and has hung.