It's an error in grc. The block 'Modulate vector' is not proper
evaluated. Just open and close the block 'Modulate vector' in the
property editor then you get the error message :
Value "digital.modulate_vector_bc(mod.to_basic_block(), data, taps)"
cannot be evaluated:
'NoneType' object has no attribute 'to_basic_block'
I think there is an error in the digital_modulate_vector.block.yml
definition.
Probably line 16 in this file
value: ${ digital.modulate_vector_bc(mod.to_basic_block(), data, taps) }
should be removed.
-- Volker
Am 20.09.21 um 21:54 schrieb Jameson Collins:
I am trying to make my own version of packet_rx.grc. I copied the
flowgraph and began modifying it. I found that at some point I started
getting this error when I open the flowgraph:
ERROR:gnuradio.grc.core.FlowGraph:Failed to evaluate variable block
modulated_sync_word
Traceback (most recent call last):
File
"/home/user/git/toolbox/conda/miniforge3/envs/gnuradio/lib/python3.8/site-packages/gnuradio/grc/core/FlowGraph.py",
line 268, in renew_namespace
value = eval(variable_block.value, namespace, variable_block.namespace)
File "<string>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'to_basic_block'
ERROR:gnuradio.grc.core.FlowGraph:Failed to evaluate variable block
modulated_sync_word
Traceback (most recent call last):
File
"/home/user/git/toolbox/conda/miniforge3/envs/gnuradio/lib/python3.8/site-packages/gnuradio/grc/core/FlowGraph.py",
line 268, in renew_namespace
value = eval(variable_block.value, namespace, variable_block.namespace)
File "<string>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'to_basic_block'
I traced the problem back to whether or not the preamble variables are
enabled in the flowgraph. However, it doesn't matter whether these
variables are actually used anywhere. They simply need to exist
otherwise this error occurs.
Please see the attached grc file. It has the minimum number of blocks
to reproduce the error. If the 3 disabled blocks are instead enabled
then the error will not occur.
