[Discuss-gnuradio] fsk_loopback.py

[Robert Roberts]

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~