On 06/23/2020 01:17 PM, Cameron Matson wrote:
I've tried from 125K to 16M (which if I request anything higher is
what the device seems to cap it at). The lower sample rates on the RX
side actually do solve the O problem, which I guess makes sense, but
the tG and U are still there on the TX side, and no packets seem to be
decoded.
Cameron
The CPU on the E310 is a dual-core ARM9 CPU clocked at 866MHz. That
means that it can't move very many samples (particularly full-duplex)
per second for a "complex" signal flow that involves
modulaton/demodulation. When doing pretty-much *nothing* to the
samples, the interface
can move a few Msps. That goes down quickly as you actually have to
do anything to the samples. The E310 has a larger FPGA, and the
"marketted use case" is to do most processing in the FPGA.
Now, as to why, at lower rates, you cannot decode, that's a debugging
exercise perhaps not related, per se, to the E310, but just
the experimental setup.
How are the two radios "connected" -- via antennae or a cable? If
cable, make sure you have plenty of attenuation in-line (30-40dB),
otherwise you risk damage to the receiver at worst, and at best,
driving the receive chain into non-linearity, producing distortions and
unwanted mixing products within the first gain stage(s).
On Tue, Jun 23, 2020 at 12:03 PM Marcus D Leech
<patchvonbr...@gmail.com <mailto:patchvonbr...@gmail.com>> wrote:
What sample rate ranges have you tried?
Sent from my iPhone
On Jun 23, 2020, at 12:57 PM, Cameron Matson
<ncmatso...@gmail.com <mailto:ncmatso...@gmail.com>> wrote:
Hello all,
I'm new to gnuradio and SDR so I hope there isn't something
obvious I'm missing. I'm trying to get a packet based system set
up. I'm using gnuradio 3.7 and UHD 3.14 that I cross compiled
and loaded onto two E312s.
I'm trying to use the uhd_packet_tx and uhd_packet_rx examples as
a staring point. I made the necessary modifications to run it as
a non-gui flowgraph, but left all the variables untouched. Both
the flow graphs run, but:
* the Tx flow graph shows an initial tG flag and then a U flag
after every burst (which I understand has something to do
with tag offsets mismatching
https://github.com/gnuradio/gnuradio/issues/1976)
* The Rx flow graph immediately starts outputing O flags, and
no packets are recieved.
I've tried playing around with the frequency and sampling rates
without much success.
Any help on where to start would be greatly appreciated.
Thanks,
Cameron
