I have a GNU Radio flowgraph where I send bytes (preamble, header, payload) from an external python program to the flowgraph through a ZMQ socket. The bytes are then modulated in the flowgraph and transmitted through the radio sink. What I would like to do is send an arbitrary bursts of data, after which the transmitter is shut down (buffers set to zero) until new data is ready to be sent.
Now, just connecting the ZMQ source to a modulator and then the radio sink will cause constant buffer underflows, and to my understanding might cause bad behaviour from the radio itself, nevermind the fact that if the data burst size is below the size of the buffer it might not get sent at all. The issue is seemingly in combining intermittent, asynchronous data with the stream based structure of GNU Radio and the discrete buffers of the SDR, however sending bursts of data instead of a continuous stream over the radio seems like an obvious thing to do, so I feel like I'm missing something.
I wrote a custom python block that aggregates packets based on tags and then outputs them, or if no packet is present simply outputs all zeros. This seems to work, but I am not sure if this is just a hack or the correct way to do this.
UPDATEsection. Just refine the question – Rodrigo de Azevedo Jul 13 '23 at 08:19