Hi Julian,
I managed to finally get data across…I was leaving the payload to automatic (0)
and it turns out I was sending messages less than the default of 512…I knew it
had to be something simple and there it is. I change the payload to 8 and now
it will send messages greater than 8 characters long in the terminal.
Thanks for the help!
Priyank
From: discuss-gnuradio-bounces+priyank.patel=gtri.gatech@gnu.org
[mailto:discuss-gnuradio-bounces+priyank.patel=gtri.gatech@gnu.org] On
Behalf Of Patel, Priyank
Sent: Tuesday, August 25, 2015 10:17 AM
To: Julian Arnold
Cc: discuss-gnuradio@gnu.org
Subject: Re: [Discuss-gnuradio] Setting up a simple packet radio in 3.7.7.2
Hi Julian,
I've verified that it works with the setup you provided (it was very similar to
a test I did initially before I switched to TCP sources/sinks). The reason I
want to use a TCP source/sink is that I want to be able to send application
data through the radio (fairly slow and small data packets, i.e. occasional
application commands).
I then switched over the Time sink to a TCP sink: address 127.0.0.1, port 9001,
client mode
I ran the code again with the sine wave still outputting as the source and
opened up a terminal with nc -l 9001 (to connect to the tcp sink client). I
was immediately able to see the data was flowing through still (it was garbled,
but data regardless in the terminal window).
I then switched the Signal Source to the TCP source: address 127.0.0.1, port
9000, server mode
I ran the code again and got nothing as I entered data into the TCP source
terminal window (using nc 127.0.0.1 9000). I added a QT GUI Number sink to the
output of the encoder and saw that the output as always 0.
I believe I am still getting blocked at the packet encoder whenever I use my
TCP source. I've tried changing the data links between the TCP source/sink and
Packet Encoder/Decoder to bytes, but still didn't change the output of the
encoder at always being 0.
Any other ideas? I feel like there must be some simple setting or method I am
using incorrectly at this point.
Thanks for your help!
Priyank
From: Julian Arnold mailto:julian.arn...@ettus.com>>
Sent: Tuesday, August 25, 2015 5:04 AM
To: Patel, Priyank
Cc: discuss-gnuradio@gnu.org<mailto:discuss-gnuradio@gnu.org>
Subject: Re: [Discuss-gnuradio] Setting up a simple packet radio in 3.7.7.2
Hi Priyank,
I rebuild your setup without the TCP source and it is working for me [1]. Can
you run it without using TCP?
You have to wait a little for the output to appear on time sink though.
Is there something I need to do for the terminal messages I am sending through
the tcp-source in order for the encoder block to properly process it?
No, generally everything should be handled within the packet encoder.
[1]
[cid:image001.jpg@01D0DF36.D8D3C690]
Cheers,
Julian
On Mon, Aug 24, 2015 at 9:47 PM, Patel, Priyank
mailto:priyank.pa...@gtri.gatech.edu>> wrote:
Hi Julian,
Thanks for responding so quickly! I've attached a picture of the current setup
(if it gets through). I've tried looking at the output of the encoder and am
seeing nothing come out of it and so there is no signal from that point on
(through the gmsk mod->gmsk demod->decoder->tcp-sink). Is there something I
need to do for the terminal messages I am sending through the tcp-source in
order for the encoder block to properly process it?
I am currently just simulating it locally by going directly between the
gmsk-mod->gmsk-demod as I wanted to make sure everything goes through before I
add in the USRPs.
Thanks,
Priyank
From: julian.arn...@ettus.com<mailto:julian.arn...@ettus.com>
mailto:julian.arn...@ettus.com>>
Sent: Monday, August 24, 2015 3:16 PM
To: Patel, Priyank
Cc: discuss-gnuradio@gnu.org<mailto:discuss-gnuradio@gnu.org>
Subject: Re: [Discuss-gnuradio] Setting up a simple packet radio in 3.7.7.2
Hi Priyank,
The packet decoder is checking for a preamble sequence in the data stream.
If there is no output coming from the decoder the preamble is probably not
being detected.
How does the output of the gmsk demod look like?
Also, are you transmitting the signal or are you just simulating locally?
Cheers,
Julian
Am 24.08.2015 um 21:05 schrieb Patel, Priyank
mailto:priyank.pa...@gtri.gatech.edu>>:
Hello,
I am trying to get a simple packet radio GRC working but so far have had no
luck with the following scheme:
tcp-source (port 9000) -> packet encoder -> gmsk mod -> gmsk demod -> packet
decoder -> tcp-sink (port 9001)
If I remove the encoder/decoder and the gmsk mod/demod and go directly between
the ports, then I am able to clearly see everything (I am using two terminals,
one for tcp source and one for tcp sink). If I add back in the gmsk mod/demod
I see stuff in my other termin