Re: [Discuss-gnuradio] UHD default subdevice.

[Andrew Davis]

I see what your saying but typing "--address 'type=usrp1' --spec 'A:0' --antenna 'TX/RX'" every time wasn't my problem. 
The problem is programs that let UHD pick the default device, I don't know how UHD chooses but it could check ~/.uhd/uhd.conf 
or something instead of guessing. As you said I could just fix the programs, but many of them are not maintained and why
fix up useless old programs when I could be fixing UHD which is still maintained and would fix the old programs in the process. 
Same for main GNUradio programs, the default device/subdevice/antenna parser options could be read from a config file too.
So does this already exist somewhere or how can I help implement it?

On Fri, Dec 23, 2011 at 5:13 PM, Marcus D. Leech <address@hidden> wrote:

Could you give me a hint? How do you interface with UHD before a C++/python program requests the device?

Well, you complained about having to "type --spec A:0" a lot, which is a natural for a shell script that starts your program--whether that
 program is written in C++ or Python, and simply pass in a fixed value for "the --spec" option to the program you're trying to run.

For example, any of the setup parameters (well, *most*) of a uhd_usrp_source or uhd_usrp_sink can be taken from a variable or command-line
 parameter, using the "variables" section in GRC, so you make them come from command-line parameters, and default those
 parameters, and again, you can make it fancier with a shell script surrounding the invocation of the target program.  In fact,
 I have one startup script that parses the output of "uhd_usrp_probe" to determine what cards I'm dealing with, and set command-line
 parameters appropriately from parsing the output of "uhd_usrp_probe".  I'm also working on an easier-to-use little python program
 that is intended to set a bunch of shell variables based on probing the hardware and setting a bunch of standard variables--specifically
 to support better autoconfiguration from within shell scripts, etc.

If the target program *doesn't support* the parameter you want as a command-line parameter, then *add it*, and submit it
 to be folded back in to the mainline.  I recently did this for uhd_fft.py and rx_cfile.py to support the "sc8" alternative wire-format, which is
 necessary to support 33.33Msps and 50Msps sample rates out of USRP2/N2XX.

--
Marcus Leech

Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org