Re: [Discuss-gnuradio] Some questions about using UHD

[Josh Blum]

> 
> When UHD is used in some cases, the comments come up as below.
> 
> (1) Target recv sock buff size: 50000000 bytes
> Actual recv sock buff size: 131071 bytes
> 

Did you see the warning it prints? It contains the instructions.

Instructions to resize the kernel socket buffers are also here:
http://www.ettus.com/uhd_docs/manual/html/transport.html#resize-socket-buffers

> 
> (2) Target sample rate: 8.000000 MSps
> Actual sample rate: 8.333333 MSps
> 
> (2) may be caused because interpolation or decimation rate must be integer.
> 
> So if the sample rate that I intended is 8.000000 MSps at TX, the
> interpolation rate(100M/8M=12.5) is not integer. Thus the actual sample
> rate is different from the target sample rate. Is my guess right?
> 
>  

correct

>  
> 
> Finally, I am curious about the UART of USRP2.
> 
> How does the UART operate in USRP2?
> 
>  

Here is the only docs I have on the UART. Honestly, its not very
interesting.

http://www.ettus.com/uhd_docs/manual/html/usrp2.html#monitor-the-serial-output

-Josh