I think you need to be a bit more explicit in what you are looking for. What exactly would you want these files to contain?
The RS device (by default) keeps a week of data, and you can copy those files out. They are in miniSEED format, which is somewhat complex (maybe overly complex for the world today), but there are tools that will extract the data (I have been using mseed2ascii). The raw data is “counts”, a unitless value from the analog to digital converter reading the ground measurement transducer.
The recorded numbers (one sample every 1/100th of a second) look like this:
TIMESERIES AM_R309F_00_EHZ_D, 6490377 samples, 100 sps, 2022-04-19T00:00:04.192999, TSPAIR, INTEGER, Counts
You can also output the data without the date/time stamp on each line for a smaller file, and keep track of the time relative to the timestamp in the header yourself.
It should be fairly clear that you probably need to re-center the values around zero (calculate an average and subtract it from each value).
If you want to convert the counts to m/s you can do so, with some programming by obtaining the calibration data for your device and using that in the conversion.
For other devices data, I did a quick search but didn’t find any advertised way to do it from the RaspberryShake servers, but the manual does mention this: