Thanks Gerhard. That was a very comprehensive answer.
I have begun some C code to read .sr files, read the metadata and then read the binary files from the scope and perform a DFFT. I am not sure yet whether this will be good enough for me to be able to get a measure of the frequency of any, or every waveform I sample with the scope, but it is a start. Mike On 25/03/2021 14:52, Gerhard Sittig wrote: > On Wed, 2021-03-24 at 18:38 +0000, Michael A Ray wrote: >> >> I want to delve into protocol decoders. For one thing I want to >> write a decoder which will read analog data from the 'scope >> samples and perform a DFFT on the data, so that I can see a >> frequency domain spectrum. >> >> This is because I am blind and cannot see pulseview, of course. > > The current sigrok infrastructure for protocol decoders > exclusively accepts logic traces as inputs. Decoder output is > either annotations (presented graphically or textual depending on > the libsigrokdecode using applications), Python output for the > consumption by stacked decoders (which again output annotations > and/or Python and/or binary), or binary output (their meaning > totally depends on the individual decoder which creates them). > > There is a recent addition of logic traces as output out of a PD. > But IIUC it's a feature that is exclusive to pulseview, and very > probably is not supported by any other application, and cannot be > used as input for other decoders (not at all, or not at the same > time with other logic input or with output from other decoders). > I could be wrong there, am not speaking for the feature's author, > am just stating my perception. Haven't even used that logic > output feature myself, only skimmed the commits when they > happened. > >> But having installed sigrok-cli, libsigrok and libsigdecode >> from git, I do not seem to have a sigrokdecode Python package >> anywhere on my system. >> >> Can somebody advise me how to get this installed? > > You don't. There is no such thing as an installable Python > package which binds the libsigrokdecode library or makes sigrok > decoders available to you. Python is _embedded_ into sigrok using > applications. See the wiki and search the mailing list. You'd > essentially have to do what these applications do to get the > input data which then is fed to the decoding library. There may > be gists which try to provide you with such an environment, but > they may be incomplete or not representative for what existing > libsigrokdecode using applications really do in combination with > libsigrok. Their existance probably is motivated by getting > _some_ essential part running in standalone mode during initial > Python decoder creation, but they certainly don't represent a > full environment that represents the feature set of mainline > sigrok applications. > >> I may not be able to run any decoders on output from the >> 'scope. But running them and looking at the operations against >> LA data, I should be able to figure out how to do my DFFT. > > Maybe you are not looking for protocol decoders as such, but > something different perhaps? > > > virtually yours > Gerhard Sittig > -- > If you don't understand or are scared by any of the above > ask your parents or an adult to help you. > > > _______________________________________________ > sigrok-devel mailing list > sigrok-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/sigrok-devel > -- Michael A. Ray Analyst/Programmer Witley, Surrey, South-east UK "Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away." -- A. de Saint-Exupery _______________________________________________ sigrok-devel mailing list sigrok-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sigrok-devel
