Re: [Discuss-gnuradio] "E" on USRP2 UART

[Josh Blum]

On 05/06/2011 12:15 PM, Leonard Marziliano wrote:
> Actually, I have some thing like this on the terminal screen:
> 
> UEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEE
>                      
> EEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEE
>                      
> EEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEE
>                      
> EEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEE
>                      
> EEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEU
>                      
> EEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEE
>                      
> EEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEE
>                      
> EEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEU and
> so on..
> 

Wow, its like artwork

U is underflow
E is some kind of mystery full duplex error condition

> As you can see, it is very regular.
> 
> To put things in context, I'm trying to develop a DVB-S2 Modulator using
> a very fast PC (six cores Xeon Dell, running Ubuntu 10.10) and the USRP2
> using C++ code. I'm not using GNU Radio. So far, I've not been very
> successful in term of getting the system running smoothly in real-time.
> When I look at the signal coming out of the USRP2 , it is very choppy.
> I've optimized a lot of code but still have the choppy issue. I'll
> looking it further but if anybody has any ideas suggestions on this,
> I'll be very happy to hear them !
> 

I would try out uhd, supposedly the tx flow control is a lot better:
http://code.ettus.com/redmine/ettus/projects/uhd/wiki

-Josh