Reading signed integers

[tddaniel]

Hello,

I am using this package during my experiments and have run into one issue. I am reading data from an instrument and it returns it as either an int8 or int16. From what I can tell the read function only returns uint8 values, is there a way to get it to read it as int8 or int16? My values can be negative so I kinda need that sign. Thanks in advance!

EDIT: I fixed the issue by shifting things manually. But I think the option would be nice if possible

[caryan]

As it look like you've already figured out you could use reinterpret to cast the data. However, you're correct it would be nice to have some convenience functions like PyVisa has.

[tddaniel]

I was actually doing it completely manually. Thanks for the pointer to reinterpret. The only thing that I find causes some issues is the high level of digitization from reading only 8 bit integers for some applications. 16 bit would be awesome.

[caryan]

I don't quite follow the 8bit vs 16bit issue. What exactly is the instrument returning? Does readavailble get all the bytes you need?

[tddaniel]

I am reading a signal off an oscilloscope, typically a very small one. I can have it return the waveform values as either int8 or int16. What I believe it is doing is making discrete bins for the data and int16 gives higher resolution than int8, due to having more bins in a given range. I think readavailable grabs everything but splits it in 8 bit chunks, I end up with twice the values I should have. So I guess i just need to figure out how to recombine them.

EDIT: I see reinterpret should do the trick, Thanks. sorry for the confusion

[caryan]

Yep, you can reinterpret an array too.