No TX on usrp_nbfm_ptt.py example

GNU Radio
1

Hi all,

Using GnuRadio (3.0) on OSX (10.4.10 Intel) with USRP (RFX400 dau) and
the example apps mostly run fine …
But the usrp_nbfm_ptt.py example receives only. The app suggests that
pressing SpaceBar should enable transmit (I’m trying PMR 446MHz band)
but absolutely nothing happens (either UI or functionally in the h/w)
when I press space. I am assuming that the UI does something to reflect
that the thing has switched to TX when it works? Receive from a
suitable handheld PMR set works fine. Any top level ideas what I am
doing wrong?
Is there anything about the hardware setup which causes the app to
inhibit TX?
Are there any jumpers or such that I need to set on the Flex400
daughterboard to allow TX?

Thanks
Jonathan.

–
Jonathan Mitchener
Futurologist & Principal Research Scientist - Devices
BT Group Chief Technology Office

e-mail: [email protected]

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2

Jonathan - For whatever reason, WX on OSX doesn’t get SpaceBar events
correctly, and/or the window of reference in the demo isn’t correctly
focussed. Either way, the demo just doesn’t do what it’s supposed to
on OSX. Your hardware and other software are most likely OK … it’s
just the demo with issues. I’ll try to make the change it suggests
(“This REALLY needs to be replaced with a hand-crafted button that
sends both button down and button up events”) … I have an internal
version that does this already, and it works quite nicely … but I
haven’t backported it yet to GR’s trunk. - MLD

On Oct 30, 2007, at 7:23 AM, [email protected]

3

I’ve created a branch for these changes to the PTT example. You can
checkout just the USRP folder with those examples, via:

svn co http://gnuradio.org/svn/gnuradio/branches/developers/michaelld/
ptt/gnuradio-examples/python/usrp

and test out “usrp_nbfm_ptt.py”. Strangely enough, moving the
"bind"ing for the space bar -before- anything else seems to fix that
problem for me. - MLD