On 2021-09-14 10:24 a.m., Rob Kossler wrote:
Hi Ivan,
If your issues are still the following: streaming works fine for FFT
length 256, but causes streaming errors at FFT lengths 512 and above,
the issue is very likely related to the packet length that the FFT
block produces.
The stock RFNoC FFT block from Ettus asserts TLAST on the final FFT
sample, which makes the packet length equal to the FFT length. For a
512 point FFT, this means that the number of bytes in a packet is
2048+header_bytes. This is a problem if the interface MTU is less
than that (often at 1500). So, the answer is to figure out how to get
the interface MTU set to a larger value. If that is not possible,
then the answer is to modify the FFT block so that the packet length
is not dependent on the FFT size. For example, the FFT block could
assert TLAST every 256 samples, independent of the actual FFT length.
There are old posts about this if you search the archive.
Rob
Thanks, Rob.
But we've already covered that territory--turns out there IS a bug in
recent UHD with FFT and FIR (and other vector functions I think) lengths
> 256, and a bug
has been raised.
On Mon, Sep 13, 2021 at 5:30 PM Marcus D. Leech
<patchvonbr...@gmail.com <mailto:patchvonbr...@gmail.com>> wrote:
On 2021-09-13 2:29 p.m., Ivan Zahartchuk wrote:
Tell me how to create a yaml file for such a graph correctly? I
tried like this but I get errors. I have not found such examples.
Please copy user-users on these e-mails. Others may have better
insights than myself on these things, and bringing in the wider
community is always a good idea.
The phrase "but I get errors" isn't terribly useful unless those
errors are included in the problem report. I MAY or MAY NOT be able
to help, since I'm not an RFNOC user or developer. But without
those errors available to the people you're asking for help,
it's pretty tough to do ANYTHING.
ср, 8 сент. 2021 г. в 02:13, Marcus D. Leech
<patchvonbr...@gmail.com <mailto:patchvonbr...@gmail.com>>:
On 2021-09-07 5:55 p.m., Ivan Zahartchuk wrote:
I am setting 256 points FFT with the following parameters:
fft_amplitude =
uhd.libpyuhd.rfnoc.fft_magnitude.MAGNITUDE_SQUARED
fft_direction = uhd.libpyuhd.rfnoc.fft_direction.FORWARD
fft_shift = uhd.libpyuhd.rfnoc.fft_shift.NORMAL After that I
do abs and display the data. Tell me how to do it better?
And do I need to set a different type for the array which is
passed to the recv function when setting Mag ** 2?
Actually, there IS a logpwr block in RFNOC. I don't know
exactly what scaling strategy it uses.
If I wanted to get power estimates out of an RFNOC FFT, I'd have:
FFT(with MAG2)--->MOVING_AVG--->KEEP-ONE-IN-N all inside
RFNOC, and then scale to my hearts content at leisurely rates
on the host.
ср, 8 сент. 2021 г. в 00:43, Marcus D. Leech
<patchvonbr...@gmail.com <mailto:patchvonbr...@gmail.com>>:
On 2021-09-07 4:17 p.m., Ivan Zahartchuk wrote:
Hello. There is any information on my question. I also
noticed that if you take the data after the FFT, then
the sensitivity drops very much. I see a -30 dBm signal
but -60 dBm is no longer displayed.
How are you scaling and displaying your FFT output?
What options do you have set on your FFT? DO you have
it using Mag**2, how do you scale it
after that?
сб, 4 сент. 2021 г. в 00:04, Ivan Zahartchuk
<adray0...@gmail.com <mailto:adray0...@gmail.com>>:
Here is my script. I am trying to read different
amounts of data from DDC and from FFT. Are there
any new statements on my question?
чт, 2 сент. 2021 г. в 10:06, Jonathon Pendlum
<jonathon.pend...@ettus.com
<mailto:jonathon.pend...@ettus.com>>:
Great, thanks. Can you also share your latest
python script?
Jonathon
On Wed, Sep 1, 2021 at 6:37 PM Ivan Zahartchuk
<adray0...@gmail.com
<mailto:adray0...@gmail.com>> wrote:
Yes, I can try it but next week. But I
still wanted to do FFT on FPGA. And one
more question. Is it possible to create two
streamers and read 256 samples one at a
time and another 8192 for example? I want
to do FFT on one channel and start a stream
with DDC for demodulation on the other.
What is possible?
ср, 1 сент. 2021 г. в 21:09, Jonathon
Pendlum <jonathon.pend...@ettus.com
<mailto:jonathon.pend...@ettus.com>>:
Hi Ivan,
Can you try running your script with
the SPP set to 512 and without the FFT
block, i.e. Radio -> Rx Streamer? This
may be a general issue with SPP
unrelated to the FFT. I'm getting the
same "Bad CHDR packet" error on a
different device with the FIR filter
block, but it goes away when I remove
the block.
Jonathon
On Mon, Aug 30, 2021 at 3:46 PM Marcus
D. Leech <patchvonbr...@gmail.com
<mailto:patchvonbr...@gmail.com>> wrote:
On 2021-08-30 2:30 p.m., Ivan
Zahartchuk wrote:
Thanks. Still trying to work this
out. In UHD 4, the interface to the
FPGA changed from a straightforward
DMA implementation--done by ADI for
their IIO subsystem, to a driver
that makes the FPGA/Radio "look"
like a network device with an MTU
of 9000.
With an MTU that large, you should
have no trouble with 512-bin FFTs.
But clearly, you are.
The "int0" network interface exists
only while there's a session with
the radio, so it won't show up in
"ifconfig" unless there's a session
active,
and it indeed has an MTU of
9000. So MTU isn't your problem.
It's something else, and I'm not
sure what at the moment.
пн, 30 авг. 2021 г. в 15:08,
Marcus D. Leech
<patchvonbr...@gmail.com
<mailto:patchvonbr...@gmail.com>>:
On 2021-08-29 7:17 a.m., Ivan
Zahartchuk wrote:
Thanks a lot. Here is my
output with uhd_usrp_probe
and my code:
Could you share with us the
output of:
ip link
or ifconfig
сб, 28 авг. 2021 г. в 20:19,
Marcus D. Leech
<patchvonbr...@gmail.com
<mailto:patchvonbr...@gmail.com>>:
On 2021-08-28 10:49 a.m.,
Ivan Zahartchuk wrote:
Tell me who I can turn
to for help or how can I
solve the problem with
the fact that I cannot
set the number of FFT
points> 256. I apologize
for my persistence, but
this is critical for me.
Thank you for understanding.
Ivan, I've been poking
around all morning try to
find where there may be a
limit. I can't find it.
I'm hampered by not being
an RFNOC expert.
I have a query in to
Ettus R&D, but it being
the weekend, I don't
expect any kind of answer
until Monday.
Could you share your
Python code, and the
output of uhd_usrp_probe
on your E310?
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