FlightAware Discussions

Newbie help. sched scan and wedged device

Hi all I over a year ago I bought the blue flightaware bundle on modmypi and managed to get it up and running.

In the last couple of months I have moved home and have just managed to get around to setting the pi up again but I am having some bother with it.

On the main page I get a warning on the receiver sating it is connected but not getting any data and MLAT is no synced with other nearby receivers.

I get the following in the log.
wpa supplicant 417 wlan0 failed to initiate sched scan and
No data has been received for a long time the dongle maybe wedged.

Any help would be much appreciated.

Maybe the antenna is not connected correctly?

Do you have console access to the RPi (local or ssh)?

You probably already tried a reboot?

I have tried a number of reboots and still the same.

I doi have access to to the pi and SSH.

Can you check the antenna connection?

Which antenna are you using?

https://www.modmypi.com/raspberry-pi/set-up-kits/rpi3-model-b-plus-kits/piaware-aircraft-tracking-kit-inc.-raspberry-pi-3

I got the above just over a year ago.

The antenna looks to be ok and connected.

To check the dongle you can do the following:

first install some stuff that is needed for the test:

sudo apt-get update
sudo apt-get install rtl-sdr

Then for the actual test:

sudo systemctl stop piaware
sudo systemctl stop dump1090-fa

rtl_test -s 24000000

After a minute you can press Ctrl-c to stop test.
The number of lost samples should be 0.

1 Like

The cable of these cheap antennas is not connected very securely to the antenna.

It might be broken.
You can test for that by inserting a piece of wire sticking out 6.9 cm long instead of connecting the antenna.
(for example into the coax connector of the filter or instead of the filter)

It should at least receive some aircraft if it is near a window and there are aircraft close.

Running the test comes back with a read and write failed -9.

Could you paste the complete output?

Just mark the text in putty (it is automatically copied) and paste here with Ctrl-v.

$ rtl_test -s 24000000
Found 1 device(s):
0: Generic, RTL2832U, SN: 77771111153705700

Using device 0: Generic RTL2832U
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
No supported tuner found
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
Enabled direct sampling mode, input 1
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9
Supported gain values (1): 0.0
Invalid sample rate: 24000000 Hz
WARNING: Failed to set sample rate.
rtlsdr_demod_write_reg failed with -9
rtlsdr_demod_read_reg failed with -9

Info: This tool will continuously read from the device, and report if
samples get lost. If you observe no further output, everything is fine.

Reading samples in async mode…
^CSignal caught, exiting!

User cancel, exiting…

Maybe dump1090-fa is not really exiting.

What does this command output (checks if dump1090-fa is running)

pgrep dump1090-fa

Does not seem to do anything that command.

That means dump1090-fa is no longer running and the test should have worked.

Seems like the prostick is not working correctly.

Maybe try another USB port or another power supply and try rtl_test again.

Just tried chaning USB ports and nothing. I have swapped the power cable out and now get.

$ rtl_test -s 24000000
Found 1 device(s):
0: Generic, RTL2832U, SN: 77771111153705700

Using device 0: Generic RTL2832U
usb_claim_interface error -6
Failed to open rtlsdr device #0.

you need to do:

sudo systemctl stop piaware
sudo systemctl stop dump1090-fa

rtl_test

otherwise dump1090-fa is still using it and the test can’t use the device.

Thought I had done it but tried again and still getting the same with new power cable.

still getting usb_claim_interface error -6 or the other stuff?

If it is still the other stuff then it seems the prostick is not working correctly anymore.

Yeah its the -9 failed stuff that I am getting.

So either both power supplies are really bad or the stick isn’t working anymore.

You could test it on a Windows computer as well but i don’t think it would change anything.

I could give it a go. Would definitely know then. Its a bit disappointing that it has not lasted long if that is the case.