Cannot get Socket-to-blob and blob-to-Socket to work with float values

GNU Radio
1

Hello everyone,

I'm doing some work with Josh B.'s extras. Basically, I made the

easiest possible message-passing program I could think of.

Signal Source [sample:44.1k, freq:1k] ----(float)----> Extras: Blob
to Socket[UDP, 127.0.0.1, 12345]

Extras: Socket to Blob[UDP, 127.0.0.1, 12345] -----(float)------>Audio
Sink[sample:44.1k]

When I attempt to run this, I get the following error message:

File
“/home/ttracy/Documents/GNURADIO/examples/companion/top_block.py”,
line 41, in init
self.connect((self.gr_sig_source_x_0, 0),
(self.extras_blob_to_socket_0, 0))
File
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py”,
line 124, in connect
self._connect(points[i-1], points[i])
File
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py”,
line 130, in _connect
dst_block.to_basic_block(), dst_port)
File
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/gnuradio_core_runtime.py”,
line 1836, in primitive_connect
Traceback (most recent call last):
File
“/home/ttracy/Documents/GNURADIO/examples/companion/top_block.py”,
line 54, in
return
_gnuradio_core_runtime.gr_top_block_sptr_primitive_connect(self,
*args)
ValueError: itemsize mismatch: sig_source_f(1):0 using 4, blob_to_udp
wrapper(6):0 using 1

Unfortunately, I have no idea what this stack trace is telling me. Can
it not handle Floats as an input?

Thanks for the help!

Sincerely,
Tom Tracy II
UVA PhD

2

On 07/10/2012 09:34 AM, Tommy T. wrote:

Hello everyone,

I'm doing some work with Josh B.'s extras. Basically, I made the

easiest possible message-passing program I could think of.

Floats have a size of 4 bytes.
You should set the item size parameter to 4.

-josh

3

On 07/10/2012 10:12 AM, Josh B. wrote:

You should set the item size parameter to 4.

I replied too quickly. Take a look at the stream to blob/blob to stream
blocks.

-josh