GNU-Radio Companion: enable/disable a block with variable

Question

I have a GRC project with multiple functionalities, but not all of them must be called at the same time. It would be a solution to divide it into several independent projects, but I'd prefer a more flexible solution which dynamically activate/deactivate some blocks in the top level flow graph.

So my idea is to enable/disable the blocks according to the value of a variable. It this possible? Or is there any alternative similar solution?

Answer 1

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EDIT If you're using GNU Radio 3.7 (and have good reason not to use any more recent release, which you really should!): Please don't use selector. It's "stop everything, reconnect blocks internally, continue everything" has terrible side effects.

If you're using GNU Radio 3.8.0.0 or later: We've replaced the above mechanism by a simple point-to-point copy, which is way more robust (but comes at a copying overhead). So, starting with 3.8-techpreview, selector is safe to use.

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Try the "Selector" block. You can set the active in/output ports with two variables.

Internally, selector is a hierarchical block, and it will pause your flowgraph, disconnect the formerly active in- and output blocks connect the now active blocks, and then continue operation of the flow graph.

In that manner, it's not sample-accurate, and might not be the tool of choice. You might want to look into message passing instead of using variables, and go for the "Multiply (with) Matrix" block.