Re: [Discuss-gnuradio] mc4020 + microtune -- ValueError: source and destination data sizes are different

[Eric Blossom]

On Tue, Jan 18, 2005 at 04:50:53PM -0500, James Cooley wrote:
> Hello, can anyone provide any advice on this error? We just built from 
> the CVS and are using a Measurement Computing card with a microtune 
> 4937. Other examples, particularly audio (dialtone, audio_play) work well.
> 
> Thanks,
> 
> -Jamie

Looks like bit rot.

Looking at the back trace, line 44 of mc4020_fft.py is the problem:

> bash-2.05b$ ./mc4020_fft.py 400
> Traceback (most recent call last):
[snip]
> line 80, in __init__
>    self.fg = flow_graph_maker (frame, self, vbox, sys.argv)
>  File "./mc4020_fft.py", line 44, in __init__
>    self.connect (cvt, block)
[snip]
>  File
> "/usr/local/gnuser/gnuradio/lib/python2.3/site-packages/gnuradio/gr/basic_flow_graph.py",
> line 192, in _check_type_match
>    raise ValueError, 'source and destination data sizes are different'
> ValueError: source and destination data sizes are different
> Unhandled exception in thread started by <bound method
> input_watcher.__bootstrap of <input_watcher(Thread-1, stopped daemon)>>

The exception is  ValueError: source and destination data sizes are different
Translation: the streams you're trying to connect have different types.

Hmmm... The code is broken.

Connecting to make_fft_sink_c is wrong, it should be make_fft_sink_f.
Can you please test and let me know if it works (All my systems are
2.6.  No access to mc4020 right now).


    def __init__(self, frame, panel, vbox, argv):
        stdgui.gui_flow_graph.__init__ (self, frame, panel, vbox, argv)

        parser = OptionParser (option_class=eng_option)
        (options, args) = parser.parse_args ()

        input_rate = 20e6
        src = mc4020.source (input_rate, mc4020.MCC_CH3_EN | mc4020.MCC_ALL_1V)
        cvt = gr.short_to_float ()
        block, fft_win = fftsink.make_fft_sink_f (self, panel, "Rx Data", 512, 
input_rate)

        self.connect (src, cvt)
        self.connect (cvt, block)
        vbox.Add (fft_win, 1, wx.EXPAND)

Eric