George - post to the list or try chat.gnuradio.org. You'll also want to post a link to your code so people can understand more about what you're trying to do.
On Sun, Jun 21, 2020 at 9:06 PM George Edwards <[email protected]> wrote: > Hi Jeff, > > Another quick question! > > Within a tagged stream Block, do you know how the value of the tag stream > is accessed? In my_crc8_impl.cc file, the tagged stream method let you > input the tagged streamed key (which I entered as the string "packet_len". > In my signal processing, I need access to the tag value that goes with this > input stream of data. Based on your latest material, I know I had it wrong > because I felt it was named packet_len (like the key string name). Based on > what you send, I have a fuzzy idea of how to extract it, but it is FUZZY. > This is my idea: > if (tag.key == "packet_len"): > pack_length = tag.value > My problem is: what is what do I write in the place of "tag"???? > > Thanks for the help. > > Regards, > George > > Thank you! > Regards, > George > > On Sun, Jun 21, 2020 at 6:15 PM George Edwards <[email protected]> > wrote: > >> Hello Jeff, >> >> Thanks! Will look at these resources. >> >> Regards, >> George >> >> On Sun, Jun 21, 2020 at 6:06 PM Jeff Long <[email protected]> wrote: >> >>> George - please reply to the list, not individuals. You'll get your >>> problem solved faster that way, too. >>> >>> You can try out your block with a vector source in GRC >>> https://wiki.gnuradio.org/index.php/Vector_Source. >>> >>> Also, the existing QA code for the vector source should give you an idea >>> how to use it in Python. Most of the QA code is written in Python rather >>> than C++. >>> >>> >>> https://github.com/gnuradio/gnuradio/blob/master/gr-blocks/python/blocks/qa_vector_sink_source.py >>> >>> >>> >>> On Sun, Jun 21, 2020 at 7:48 PM George Edwards <[email protected]> >>> wrote: >>> >>>> Hi Jeff, >>>> >>>> Thanks for the response. Please bear with me a little because of my >>>> newness to gnuradio. >>>> I looked up vector source and tagging and found the following for a >>>> tagged list: [int offset, pmt key, pmt value, pmt srcid] >>>> >>>> In my case my input vector is:: src_data = array([1, 0, 1, 0,...1,,1]) >>>> with 10 values. Do I write the syntax as follows for the QA test code: >>>> gr::tag_t(int 0, pmt "packet_len", pmt 10, pmt src_data)??? >>>> >>>> Thanks for the help. >>>> >>>> Regards, >>>> George >>>> >>>> On Sun, Jun 21, 2020 at 5:09 PM Jeff Long <[email protected]> wrote: >>>> >>>>> If you are trying to create a test vector to feed into a block that >>>>> needs a tag named "length", you can use a Vector Source. That block allows >>>>> you to define a vector of data along with tags. >>>>> >>>>> On Sun, Jun 21, 2020 at 6:38 PM George Edwards <[email protected]> >>>>> wrote: >>>>> >>>>>> Hello, >>>>>> >>>>>> New to gnuradio and I am making an OOT CRC8 module to take a tagged >>>>>> bit stream (1's and 0's) and generate the CRC and attach the CRC to the >>>>>> end >>>>>> of the data and pass it on to the next block. Also, I am encapsulating >>>>>> both >>>>>> the generator and check sum in same block using a boolean variable >>>>>> "check" >>>>>> to determine operation. >>>>>> >>>>>> In QA test I get the following error: >>>>>> gr::log :FATAL: my_crc8_bb0 - Missing a required length tag on port 0 >>>>>> at item #0. >>>>>> thread [thread-per-block[1] < block my crc8_bb(2)>] Missing length tag >>>>>> >>>>>> I modified the QA test vector by writing the length of the input >>>>>> string of 1's and 0's as the first element in the input data array, but >>>>>> it >>>>>> gave the same error as typed above. >>>>>> >>>>>> Questions: >>>>>> Q1. How do I write in the input test vector, or what do I add to what >>>>>> I already have to make the module aware of the tag length? >>>>>> >>>>>> Q2. In the my_crc8_bb_impl.cc file in the tagged stream method, I >>>>>> specified the tag name as "packet_len". In the signal processing in this >>>>>> .cc file, I assume the value of packet_len is available to me for use as >>>>>> a >>>>>> parameter and I used it. Are there some other things I need to do in this >>>>>> "my_crc8_bb_impl.cc file" to make the module more aware of input tagged >>>>>> stream data (maybe I am not binding "packet_len" properly)? >>>>>> >>>>>> I greatly appreciate any help! >>>>>> >>>>>> Regards, >>>>>> George >>>>>> >>>>>
