Hi,
I am trying to simplify my previous email for clarification. I am looking
to resolve the following issue:
I have two flowgraphs:
1. USRP Source --> File Sink # self.file_sink =
gr.file_sink(gr.sizeof_gr_complex*1, "Data.dat")
2. USRP Source --> Null Sink
I have defined both of them inside a class. I use unlock --> disconnect -->
connect --> lock to switch from one flow graph to the other. When I connect
USRP-->Null, I work on the stored data of "Data.dat" file. Thereafter, I
want to clear the data of the "Data.dat" file. I use the following line of
code to obtain my goal:
open("Data.dat",'w').close()
However, this command does not seem to erase the data of "Data.dat" file,
i.e., when I run flow graph 1 again, the previous file does not get erased.
The file size of "Data.dat" keeps growing with each run of flow graph.
How can I erase the contents of the file sink before I switch to flow graph
#1?
Any suggestion will be very appreciated. Sorry for sending two emails on
the same matter.
Thanks,
Nazmul
On Sun, Aug 5, 2012 at 6:46 PM, Nazmul Islam <mnis...@winlab.rutgers.edu>wrote:
> Hello,
>
> I have an application where I need to collect the data for 5 seconds from
> the USRP source and do offline processing for 5 seconds in a repeated
> manner. I am planning to use the lock & unlock features of the gnuradio to
> obtain my goals. The major part of my code is given below:
>
>
> class SingleSource(grc_wxgui.top_block_gui):
>
>
> self.source =
> .....
> # Source block
> self.throttle =
> ......
> # throttle
> self.file_sink = gr.file_sink(gr.sizeof_gr_complex*1,
> "Data.dat") # File Sink
> self.null_sink =
> ............
> # Null sink
>
> self.connect((self.source, 0), (self.throttle,
> 0))
> self.connect((self.throttle, 0), (self.sink, 0))
>
> def reconf1(self):
> self.disconnect((self.gr_throttle_0,
> 0),(self.gr_file_sink_0, 0)) # Disconnecting the throttle & the
> file sink
> self.connect((self.gr_throttle_0, 0),
> (self.gr_null_sink_0, 0)) # re-connecting the throttle & the
> null sink
>
> def reconf2(self):
> self.disconnect((self.gr_throttle_0,
> 0),(self.gr_null_sink_0, 0)) # disconnecting the throttle & the
> null sink
> self.connect((self.gr_throttle_0, 0),(self.gr_file_sink_0,
> 0)) # re-connecting the throttle & the file sink
>
> ................................
>
>
> if __name__ == '__main__':
>
> tb = SingleSource()
> var = 1
>
> tb.start()
> # Flow graph starts
> for loop in range(0,2):
>
> sleep(5)
> # Collects the data in the file sink
>
> tb.lock()
>
> tb.reconf1() #
> Flowgraph gets locked & reconfigured and unlocked
>
> tb.unlock() # Now,
> data is going to the null sink. I don't need this data
> sleep(5)
>
> ................. # Offline
> processing
> open("SineData.dat",'w').close() # I
> WANT TO ERASE THE DATA IN THE FILE SINK AFTER PROCESSING
>
> # SO THAT THE FILE SIZE DOES NOT BIGGER
> tb.lock()
> tb.reconf2() # File
> sink is getting reconnected so that I can collect the data in the next run
>
> tb.unlock()
>
> Now, the problem is: the file size of "SineData.dat" should not grow with
> each loop since I am using open("SineData.dat",'w').close() . In each new
> loop, I expect the file to only contain the latest information and not the
> previous ones. However, I am finding that the file size keeps growing with
> each loop, i.e., the open("SineData.dat",'w').close() command is not
> working.
>
> Any suggestion will be very appreciated.
>
> Thanks,
>
> Nazmul
>
>
> --
> Muhammad Nazmul Islam
>
> Graduate Student
> Electrical & Computer Engineering
> Wireless Information & Networking Laboratory
> Rutgers, USA.
>
>
--
Muhammad Nazmul Islam
Graduate Student
Electrical & Computer Engineering
Wireless Information & Networking Laboratory
Rutgers, USA.
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