On 08/08/2024 20:48, Q W wrote:
Hi Marcus,
Thanks very much for your comments. I am sorry for sending my enquiry
to the wrong mail-list. I agree with you that usrp users mailing list
would be a better place to seek for help.
I am new to SDRs and this mail list system, and really appreciate your
feedback. I come from the theoretical study of wireless
communications, and this is my first practical project. Would you
please be more specific on SPI and GPIO on N200? I reckon there won't
be heavy traffic on the SPI/GPIO connection for control signals, so
not sure if high data rate is necessary. Also can you please advise if
there is any other interface on N200/N210 which I can use for the
control purpose?
Kind regards,
Tom
The SPI interface from the motherboard is really intended for
communication with the internal workings of the daughtercards
it connects to.
The GPIO is normally controlled by a host-based API, but one could write
custom FPGA code to make GPIO do things in a more
"clocked" fashion. One could even, I suppose, bring the SPI signals
out of the box, but that isn't a supported thing, and
both host-side and FPGA code would likely be required to make that work.
The N200 isn't really intended to operate without *SOME* kind of
daughtercard(s) installed. The motherboard itself
doesn't really "do" RF by itself.
On Friday, 9 August 2024 at 10:28:00 am AEST, Marcus D. Leech
<patchvonbr...@gmail.com> wrote:
On 08/08/2024 20:18, Q W wrote:
Hi there,
We are considering using a USRP N200 for a project, and want to figure
out some technical details before placing the order. We plan to use
N200 to control our own device based on the analog RF signal sent from
the device.
The general structure is to have the device’s output connected to the
Rx port of N200. The outputsignal is processed in N200 and leads to
the control (digital) signals which are fed back to tune the device.
We plan to use SPI/GPIO ports for the feedback channel. My question is
if such SPI/GPIO ports are available on N200? Please note that our
device is not a daughter board, so I am not sure if the SPI/GPIO shown
on the data sheet of N200 can be used for the control purpose.
If SPI/GPIO is not available for such control, is there any other
connection interface for the control signal sent from N200? Our own
device can be relatively flexible, so any connection scheme can be
considered.
Kind regards,
Tom
USRP-specific questions should probably be posted on the usrp-users
mailing list, rather than here.
However. In the N200/N210 devices, the GPIO was exposed on the
daughtercards. SPI was really only used internally,
between the motherboard and whatever daughter card(s) were installed.
The GPIO wasn't really designed for high-speed "stuff", which is what
you'd need to "bit bang" an SPI interface out of
the GPIO pins on whatever daughtercard you're using.
