Hi Marcus,
Thanks for the suggestion. While still using the Python block, I tried changing the sources to CONST_WAVE and decreasing the sample rate to 500K, and proceeded to do that all the way down to 1, and it still was producing Us on the output.
Having said that, I turned to implementing the block in C++, and I have gotten far enough to the point where I am having mismatched sizes, and I'm not sure why. Specifically, the cosines are sampled at 1M and produce complex outputs, and they go into the inputs of the c_plus_plus block, but the error I keep getting is this:
"Source IO size "8" does not match sink IO size "4000000"."
While I know something is probably wrong with my inputs and outputs of the C++ block, I don't understand why the cosine size is 8 and why my sink IO size is 4000000. I tried changing the sampling rate too, to see if that changed the size from 8 to something else, but it doesn't. In my block, the relevant code from the cc file is:
babf_c_plus_plus_impl::babf_c_plus_plus_impl()
: gr::sync_block("babf_c_plus_plus",
gr::io_signature::make(2, 2, sizeof(gr_complex)),
gr::io_signature::make(2, 2, sizeof(gr_complex)))
{}
So, the inputs of the block and outputs of the block are just of size gr_complex, which I believe is 64 bits (real and imag are 32 bits each), so where is the 4000000 coming from? I guess I'm a bit confused about these sizes and where the issue could be. Thank you again for all the help. Such slow progress, sadly :/.