On 08/02/2016 02:19 PM, Mike Meyer wrote: > On Tue, Aug 2, 2016 at 3:24 AM <b...@biot.com> wrote: >> That's what the demo driver is for. It generates analog streams as well >> (sine waves and such), and can be configured to some extent. >> > > Unfortunately, it doesn't generate frame markers. I think it should, but I > could be confused about what they're for.
They were originally intended for the specific case of oscilloscope output. Scopes do a capture to an internal buffer, then send that buffer to the sigrok host, and then wait for a trigger to do it all over. That means the second batch of data is not contiguous with the one before it, or the one after -- it's a frame i.e. internal buffer worth of data. What the demo driver generates _is_ a contiguous set of data, of the size you ask, you frame markers would be wrong. >> This being sigrok however, any input will do: by the time it reaches an >> output module, it doesn't matter whether the analog stream came from >> hardware or a .WAV file. >> >> If you're specifically looking for something that generates frame >> markers, I think it's mostly only oscilloscope drivers that generate >> those. But do you really need those for gnuplot output? That seems to me >> like it should just generate a continuous stream. >> > > I'm honestly not sure. The frame markers don't seem to be documented on the > Wiki, so I'm cribbing from the csv output file. Which has code for handling > them. Of course, I just tried writing two analog values out as a csv file, > and it failed to write the second value, so maybe it's wrong. > > I'm thinking some kind of framing is needed for mixed signal devices, > because you need multiple packets to build a sample across all the sensors. Yes, it does make some sense to re-use them for this. The Arachnid re:load pro does this to group voltage and current measurements of a sample iteration. Probably the scpi-pps driver should do this too, can't remember why I didn't put that in there. > Well, I want to be able to do waveform analysis in a decoder. That means I > need some way of getting analog values out to them. I don't think that > transform framework would help with that, as I just want the waveforms, not > a transform of them. But I haven't even looked at the code to start > planning how to do this, so if you think it would solve my problem, I'm > certainly willing to consider it. Yup, that's a good use-case. -- Bert Vermeulen b...@biot.com ------------------------------------------------------------------------------ _______________________________________________ sigrok-devel mailing list sigrok-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sigrok-devel
