[Discuss-gnuradio] Generating a few NRZI bytes (Re: Ettus N210 GMSK 9600)

[Andy Walls]

On Fri, 2016-03-25 at 11:07 -0600, Tom Golden wrote:
> AX.25 data is NRZI encoded (so inverse bits and then NRZ).  I hand
> calculated the HDLC frame start byte and first few address bytes

Hi Tom,

The attached flowgraph might save you the hassle of working out the NRZI
bit encoding by hand, for a few bytes anyway.

I structured the input vector's tail to have a single 0 in it to
alternate the starting state (0 or 1) of the NRZI encoding, so you get
both possible NRZI encodings  displayed for the bit sequence.

The start of the vector is marked with the "sov" tag.

Obviously this could be done in Octave or MatLab or Python or whatever
as well.

-Andy

nrzi_test.grc
Description: application/xml