Re: [Discuss-gnuradio] USRP digital I/O

[Juha Vierinen]

On Jan 28, 2008 11:54 PM, Matt Ettus <address@hidden> wrote:
> Steven Clark wrote:
> > I asked the same thing a year or so ago, didn't get much of an answer.
> >
> > AFAIK, there are no software hooks for the digital I/O pins. What we
> > ended up doing was editing the verilog such that the sign of the real
> > component sent to the BasicTX dboard came out on 1 I/O pin, and the
> > sign of the imag component went to another pin. One pin was data, the
> > other clock. We used the Quartus software to generate another .rbf
> > file, in other words. Just set the gain of the tx dboard to the min
> > and ignore its analog output. This worked fine for us.

I believe Johnathan is currently working on something called gr-gpio,
which will hopefully be released soon. It will basically be just this,
but it will also include RX. This will allow sending and receiving
digital i/o syncronously with the transmitted waveform, at the cost of
reducing dynamic range by 1 bit in the I and Q components of the
signal. There is a fixed delay involved, which you have to take into
account.

juha