[Discuss-gnuradio] max_streams problem in own module

[Charles Clancy]

I'm trying to write a gnuradio 2.2 module that computes the phase of a 
complex baseband signal, mostly as a learning excercise in developing a 
4-FSK receiver.  (Is there an existing module that could do this for me?) 
I know my installation works, because I've used it for lots of other fun 
stuff so far.

I have mypkg.i that defines the package and the mypkg_phase_cf class. 
Then there are the associated mypkg_phase_cf.[cc|h] files defining the 
class.  It all compiles properly using the following:

  CXXFLAGS = -I$(GNURADIO) -I$(GNURADIO)/swig -I$(PYTHON)
  LDFLAGS = -lgnuradio-core -lcppunit -lm -lrt -lpthread

  swig -c++ -python $(CXXFLAGS) -module mypkg -o mypkg.cc mypkg.i
  g++ $(CXXFLAGS) -c mypkg.cc -o mypkg.o
  g++ $(CXXFLAGS) -c mypkg_phase_cf.cc -o mypkg_phase_cf.o

  ar rv _mypkg.la mypkg.o mypkg_phase_cf.o
  ld -shared $(LDFLAGS) -o _mypkg.so -lc mypkg.o mypkg_phase_cf.o

The constructor for mypkg_phase_cf is:

  mypkg_phase_cf::mypkg_phase_cf ()
    : gr_block ( "phase_cf",
                 gr_make_io_signature (1,1,sizeof(gr_complex)),
                 gr_make_io_signature (1,1,sizeof(float)) ) {}

In my script I have:

  from gnuradio import gr
  from gnuradio import mypkg
  ...
  arctan = mypkg.phase_cf ()
  fg.connect (baseband, arctan)
  fg.connect (arctan, sink)

When I run the script, everything links happily, and I am able to import 
the package.  However, when I get to "fg.connect (baseband, arctan)", I 
get the following error:

  File "/usr/local/lib/python2.3/site-packages/gnuradio/gr/basic_flow_graph.py",
  line 180, in _check_port
    if signature.max_streams () == -1: # infinite
  AttributeError: 'str' object has no attribute 'max_streams'

Any ideas?

[ t. charles clancy ]--[ address@hidden ]--[ www.cs.umd.edu/~clancy ]
[ computer science ]-----[ university of maryland | college park ]