Re: [USRP-users] C++ --> GRC(Socket PDU ---> QT Frequency GUI)

2017-08-03 Thread Jack White via USRP-users
Hi, Here are the top cycle-eaters. I knew that the frequency xlating fir filter was quite hungry, but I'm unsure of how to decide on a transition bandwidth. I have changed it from 1kHz to 3kHz (that is taps = firdes.low_pass(1,614400,2.5*9600,3000)) and the flowgraph seems to be running without

Re: [USRP-users] C++ --> GRC(Socket PDU ---> QT Frequency GUI)

2017-08-03 Thread Marcus Müller via USRP-users
Hi Jack, that is really peculiar, as 400k is really not a rate I'd assume you'd be getting into trouble. I'd agree with your interpretation of the netstat observations – but really, why on earth would the kernel be so short on ressources that it has to drop packets? This calls for an

Re: [USRP-users] C++ --> GRC(Socket PDU ---> QT Frequency GUI)

2017-08-03 Thread Marcus Müller via USRP-users
Ah! You've set the data type of the QT GUI sink to "complex message"; I wasn't aware that this feature had made it to the master branch :) > The point of moving to C++ was that the flowgraph I /really/ want to > use is just causing me huge problems - most notably that there are > periods of a few

Re: [USRP-users] C++ --> GRC(Socket PDU ---> QT Frequency GUI)

2017-08-02 Thread Marcus Müller via USRP-users
Hi Jack, PDUs are not just samples one after the other – they contain metadata. I can't really imagine what your flow graph looks like, so I'd be grateful for a screenshot (File->Screen Capture). Anyway, there'd be no obvious reason your UDP detour would make things faster – maybe the

[USRP-users] C++ --> GRC(Socket PDU ---> QT Frequency GUI)

2017-08-02 Thread Jack White via USRP-users
Hi, I've been having some difficulty getting reliable data flow from my USRP X310 with a GRC flowgraph, so I'm trying out writing my system in C++ with the UHD driver API. My first step has been to retrieve samples from the X310, forward them to a UDP port and then pick them up with a GRC Socket