Fsk_loopback.py

GNU Radio
1

Hello everyone,

Has anyone worked with fsk_loopback.py? I have been analyzing it and
using a file with ascii characters as an input, but I get no output.

I am trying to develop a system that will transmit text from one machine
to another. Based on the FSK code, I first made this program:

src = gr.file_source(gr.sizeof_char, ‘input.dat’, False)
snk = gr.file_sink(gr.sizeof_char, ‘output.dat’)
connect(src, snk)

It correctly transferred “Hello World.” to the output.
This let me test that GNURadio can read/write basic text files

Next, I wrote code with no FSK component that just does the
data handling. (I plan to write ASK,PSK, and FSK code eventually)

packet_size = 16

src = gr.file_source(gr.sizeof_char, ‘input.dat’, False) #data
frame = gr.simple_framer(packet_size) #put into
packets
pcm = gr.bytes_to_syms() # convert to
±1
corr = gr.simple_correlator(packet_size) # Correlate
the data
snk = gr.file_sink(gr.sizeof_char, ‘output.dat’) # store is
again
connect(src, frame, pcm, corr, snk)

I get a 0 byte output file in this case

If I connect pcm to a floating point file sink I get data.

I then tried using my text file on fsk_loopback.py and I get a 0 byte
output file. Any advice on what I am doing incorrectly?

Thanks,

~Chris Roberts~

2

On Wed, Jun 21, 2006 at 04:46:52PM -0400, Robert R. wrote:

Hello everyone,

Has anyone worked with fsk_loopback.py? I have been analyzing it and
using a file with ascii characters as an input, but I get no output.

Sorry, that fsk code should be removed. It doesn’t work well.
Please consider using the gmsk2 code. The basic tx and rx examples
are gnuradio-examples/python/gmsk2/benchmark_gmsk_{tx,rx}.py

Eric

3

On Wed, Jun 21, 2006 at 04:46:52PM -0400, Robert R. wrote:

Has anyone worked with fsk_loopback.py? I have been analyzing it and
using a file with ascii characters as an input, but I get no output.

I’ve removed it from CVS :wink:

Eric