Re: [Discuss-gnuradio] Where can I find C++ source code of an API

[Ben Reynwar]

The basic idea in gnuradio is that you're stringing signal processing
blocks together.  There's some scheduling going to work out when
different blocks are doing number crunching which I know nothing
about.  Each block has a "work" or a "general_work" function that is
called by the scheduler (I think) when it is that block's turn to
crunch numbers.  "input_items" is the data that is being passed from
the previous block in the flow graph to this block.  I'm fairly new to
gnuradio too so if you need more detailed info than that, then I won't
be much help.

Cheers,
Ben

On Sun, Mar 20, 2011 at 3:16 PM, Fengyuan Gong <address@hidden> wrote:
> Hi, Ben,
> From line 59 of gr_probe_avg_mag_sqrd_c.cc, mag_sqrd is the "input"
> variable. mag_sqrd comes from pointer in at line 58. Pointer in comes from
> pointer input_item at line 55. I know &input_item is a parameter of function
> work at line 52. My question is that where will work function be called and
> what value will be passed for the argument &input_item?
> Thanks~
> Fengyuan
>
> On Sun, Mar 20, 2011 at 5:43 PM, Ben Reynwar <address@hidden> wrote:
>>
>> Maybe I'm misunderstanding your question.
>> It looks to me like line 59 of gr_probe_avg_mag_sqrd_c.cc is calling
>> the filter function.  So "input" in that function is just the value
>> that is being passed in there.
>>
>> On Sun, Mar 20, 2011 at 2:27 PM, Fengyuan Gong <address@hidden>
>> wrote:
>> > Hi, Ben,
>> > I know where to find d_iir, which is actually an instance from class
>> > gr_single_pole_iih.h .
>> > If you have time to take a look at line 92 in gr_single_pole_iih.h,
>> >   output = d_alpha * input + d_one_minus_alpha * d_prev_output;
>> > My question is where the input comes from? I think input is coming from
>> > RSSI
>> > value reading in from USRP. But not sure how to get it?
>> > Best Regards~
>> > Fengyuan Gong
>> > On Sun, Mar 20, 2011 at 3:03 PM, Fengyuan Gong <address@hidden>
>> > wrote:
>> >>
>> >> Hi, Ben,
>> >> Thank you for your answer.
>> >> In /gnuradio-core/src/lib/general/gr_probe_avg_mag_sqrd_c.cc file, I
>> >> saw
>> >> d_unmuted = d_iir.prev_output() >= d_threshold; will determine unmuted
>> >> to
>> >> be true or false.
>> >> Then I want to know what is the C++ source code for d_iir.prev_output()
>> >> function.
>> >> I try to find it using find . -name "d_iir.*"
>> >> but nothing found.
>> >> why?
>> >> Best Regards~
>> >> Fenyuan Gong
>> >>
>> >> On Sun, Mar 20, 2011 at 2:38 PM, Ben Reynwar <address@hidden> wrote:
>> >>>
>> >>> On Sun, Mar 20, 2011 at 10:58 AM, Fengyuan Gong
>> >>> <address@hidden>
>> >>> wrote:
>> >>> > Hi,
>> >>> > I am a new learner of gnuradio. I want to know how gnuradio do
>> >>> > carrier
>> >>> > sensing. In the following function,
>> >>> >     def carrier_sensed(self):
>> >>> >         """
>> >>> >         Return True if we think carrier is present.
>> >>> >         """
>> >>> >         #return self.probe.level() > X
>> >>> >         return self.probe.unmuted()
>> >>> > I don't know what is the C++ source code for probe.unmuted, can
>> >>> > anyone
>> >>> > tell
>> >>> > me where to find it? I want to know how C++ get RSSI and process it
>> >>> > to
>> >>> > get
>> >>> > whether carrier is present or not.
>> >>> > Thanks~
>> >>> > Fengyuan Gong
>> >>> > _______________________________________________
>> >>> > Discuss-gnuradio mailing list
>> >>> > address@hidden
>> >>> > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>> >>> >
>> >>> >
>> >>>
>> >>> Earlier in python file you see:
>> >>>
>> >>> self.probe = gr.probe_avg_mag_sqrd_c(thresh,alpha)
>> >>>
>> >>> The naming convention is that a python block gr.probe_avg_mag_sqrd_c
>> >>> is defined in C++ as
>> >>> gr_probe_avg_mag_sqrd_c.  The files defining it will shared that name.
>> >>>
>> >>> Assuming you're using something unix-like you can find it by
>> >>>
>> >>> find . -name "gr_probe_avg_mag_sqrd_c.*"
>> >>>
>> >>> and you'll see the source is at
>> >>>
>> >>> gnuradio-core/src/lib/general/gr_probe_avg_mag_sqrd_c.*
>> >>
>> >
>> >
>
>