I am trying to run dump978 on linux debian buster rasp pi 3 it gets stuck on “Allocating 15 zero-copy buffers” when I run the command rtl_srd -f 978000000 -s 2083334 -g 48 - | ./dump978 | ./uat2text
Is there a bug in the code I need to fix or is it just slow?
This will be the unmaintained old version. You should use dump978-fa instead: GitHub - flightaware/dump978: FlightAware's 978MHz UAT demodulator
That said, the pipeline that you’re using will only emit something when it hears a 978 message. Maybe there are no 978 messages to hear.
When using dump-fa and there are no nearby signals would an output such as
Signal caught exiting!
Shirt write, samples lost, exiting!
Happen when running
rtl_sdr -f 978000000 -s 30000 -g 48 - | ./dump978 | ./uat2text
I don’t know why you’d want to try a 30kHz sampling rate, that’s just not going to work.
dump978 is unsupported, please try dump978-fa.
I am using dump978-fa. The 30 kHz was just me experimenting to see if increasing it would help. Gives the same output with 15,20,25 and 30 kHz.
dump978-fa is standalone and does not require separate use of rtl_sdr / uat2text
The demodulator of both dump978 and dump978-fa expects a sample rate of exactly twice the UAT bitrate (i.e. 2.083334MHz); anything else will just not work at all. 30kHz is just never going to work regardless of what you do with the demodulator anyway, it’s way too slow.
Do you know what the error “Failed to submit transfer 1” means? I am running command:
./dump978-fa --sdr driver=rtlsdr,serial=00000001
Thanks. I am getting the same thing but without the Allocating 15 zero-copy buffers. Maybe because I am not using a pi and just running it on a linux laptop due to ram issues with pi.
This is probably librtlsdr complaining about an error from libusb.
One cause is that you’re hitting the system-wide usbfs buffer size limit. Try increasing /sys/module/usbcore/parameters/usbfs_memory_mb
This is what I get on Linux Debian 11.5 amd64 on Oracle VM in Windows PC:
CLICK ON SCREENSHOT TO SEE LARGER SIZE
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