Re: [Discuss-gnuradio] What time is it?

[Matt Ettus]

On 01/18/2010 01:02 PM, Per Zetterberg wrote:
> Josh Blum wrote:
> > Glad you are trying out the branch. A few notes here:
> >
> > 1) There is a bug where after power-up, everytime (but the first) you
> > restart streaming and get samples there is junk data, and it will read
> > "bad vrt header". Its harmless, but should be fixed
> >
> > 2) FYI The second parameter to start_rx_streaming, if left out, means
> > stream asap.
> >
> > 3) The time registers are write only. There is no control packet to
> > read-back time registers. That should be removed from the code.
> >
> > 4) There needs to be a way to set the time on the next pps. This must
> > be added, I am working on this now.... When done, you should be able
> > to get the timestamp off of the serial port of a gps device and sync
> > up the usrp2 to the correct seconds. Or use your own free-running
> > seconds...
> >
> > 5) When you didnt get any samples back after setting time time: I cant
> > tell if this is a bug or just a bad time. I will test this out
> >
> > -Josh
> Does this imply that timestamps are completely useless without a pps
> signal ?
>
> 4) This sounds brilliant!


Sync on pps only makes sense if you actually have a PPS signal coming 
in.  If not, you'll need to use the free-running seconds count.

Matt