# Update Channel coding toolbox to Gnuradio 3.7.0 **URL:** \ **Category:** GNU Radio\ **Created:** [June 25, 2014, 9:56am UTC](https://www.ruby-forum.com/t/update-channel-coding-toolbox-to-gnuradio-3-7-0/230591 "2014-06-25T09:56:42Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![jason\_sam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/7993a0/32.png) [@jason\_sam](https://www.ruby-forum.com/u/jason_sam)\ **Post date:** [June 25, 2014, 9:56am UTC](https://www.ruby-forum.com/t/update-channel-coding-toolbox-to-gnuradio-3-7-0/230591/1 "2014-06-25T09:56:42Z")
Deal all, Does anyone update the Channel Coding ([https://www.cgran.org/wiki/chancoding](https://www.cgran.org/wiki/chancoding)) toolbox so that it can work in Gnuradio 3.7.0? I did try to install this toolbox. The installation was done but it do not appear in Gnuradio Companion interface. Thanks, Hoang ---
**Author:** ![Hoang\_Ngo\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/97f17d/32.png) [@Hoang\_Ngo\_K](https://www.ruby-forum.com/u/Hoang_Ngo_K)\ **Post date:** [June 25, 2014, 10:25am UTC](https://www.ruby-forum.com/t/update-channel-coding-toolbox-to-gnuradio-3-7-0/230591/2 "2014-06-25T10:25:15Z")
Hi Hoang, GNU Radio 3.7 has the gr-fec framework, and recent updates brought more performance and some features, so if that matches your use case, go ahead and try it out! Greetings, Marcus ---
**Author:** ![Hoang\_Ngo\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/97f17d/32.png) [@Hoang\_Ngo\_K](https://www.ruby-forum.com/u/Hoang_Ngo_K)\ **Post date:** [June 25, 2014, 11:28am UTC](https://www.ruby-forum.com/t/update-channel-coding-toolbox-to-gnuradio-3-7-0/230591/3 "2014-06-25T11:28:18Z")
Thank you Marcus. I’ve checked out gr-fec. The problem is that Decode CCSDS 27 block takes float input while my data to feed it is in byte. On Wed, Jun 25, 2014 at 3:23 PM, Marcus Müller [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![Hoang\_Ngo\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/97f17d/32.png) [@Hoang\_Ngo\_K](https://www.ruby-forum.com/u/Hoang_Ngo_K)\ **Post date:** [June 25, 2014, 3:56pm UTC](https://www.ruby-forum.com/t/update-channel-coding-toolbox-to-gnuradio-3-7-0/230591/4 "2014-06-25T15:56:36Z")
On Wed, Jun 25, 2014 at 5:27 AM, Hoang Ngo K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Thank you Marcus. > > I’ve checked out gr-fec. The problem is that Decode CCSDS 27 block takes > float input while my data to feed it is in byte. If you’ve built the documentation of the latest version of GNU Radio, look at the Forward Error Correction page for a description of the new FEC API. It’s designed with exactly your issue in mind. You would write a new deployment for the FEC of your choice to handle the data type conversions. In fact, the current CC decoder actually takes in bytes but the deployment takes in floats. The floats are intended to be soft symbols, and the decoder deployment converts from the soft symbol floats to a quantized soft symbol byte that floats at a particular level. Tom ---
**Author:** ![Hoang\_Ngo\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/97f17d/32.png) [@Hoang\_Ngo\_K](https://www.ruby-forum.com/u/Hoang_Ngo_K)\ **Post date:** [June 28, 2014, 5:25am UTC](https://www.ruby-forum.com/t/update-channel-coding-toolbox-to-gnuradio-3-7-0/230591/5 "2014-06-28T05:25:40Z")
Thank you Tom. I’ve modified the Decode CCSDS 27. In particular, I changed the code in implementation file (.cc): Existing code: > ``` > unsigned char sym = (unsigned char)(floor(sample)); > // printf("%li\n", *(out-1), metric); > } > } > > d_count++; > } > > ``` My code: > ``` > byte = in[ni]; > } > } > > ``` ``` ni ++; ``` > ``` > d_count++; > > ``` > > } I also modify the header file, xml file. Now the new block appear in GRC. I build a flow graph (see in attachment) to test this block. When I run this flowgraph, I got this error: init::console\_sink\_bb Traceback (most recent call last): File “/home/khachoang/GNU\_Radio/Test GRC/top\_block.py”, line 58, in tb = top\_block() File “/home/khachoang/GNU\_Radio/Test GRC/top\_block.py”, line 43, in **init** self.connect((self.fec\_encode\_ccsds\_27\_bb\_0, 0), (self.fec\_decode\_ccsds\_27\_bb\_0, 0)) File “/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top\_block.py”, line 130, in connect self.\_connect(points[i-1], points[i]) File “/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top\_block.py”, line 142, in \_connect dst\_block.to\_basic\_block(), dst\_port) File “/usr/local/lib/python2.7/dist-packages/gnuradio/gr/runtime\_swig.py”, line 4100, in primitive\_connect return \_runtime\_swig.top\_block\_sptr\_primitive\_connect(self, \*args) _ValueError: itemsize mismatch: encode\_ccsds\_27\_bb0:0 using 1, decode\_ccsds\_27\_bb0:0 using 4_ Is my code correct? How could I fix this bug? Thanks _,_ Hoang ---
**Author:** ![Hoang\_Ngo\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/97f17d/32.png) [@Hoang\_Ngo\_K](https://www.ruby-forum.com/u/Hoang_Ngo_K)\ **Post date:** [June 28, 2014, 4:45pm UTC](https://www.ruby-forum.com/t/update-channel-coding-toolbox-to-gnuradio-3-7-0/230591/6 "2014-06-28T16:45:07Z")
On Fri, Jun 27, 2014 at 11:24 PM, Hoang Ngo K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > ``` > > // Translate and clip [-1.0..1.0] to [28..228] > > viterbi_butterfly2(d_viterbi_in, d_mettab, d_state0, d_state1); > > } > > > > // long metric = > > > > ``` > > I also modify the header file, xml file. Now the new block appear in GRC. > self.connect((self.fec\_encode\_ccsds\_27\_bb\_0, 0), > return \_runtime\_swig.top\_block\_sptr\_primitive\_connect(self, \*args) > > _ValueError: itemsize mismatch: encode\_ccsds\_27\_bb0:0 using 1, > decode\_ccsds\_27\_bb0:0 using 4_ > Is my code correct? How could I fix this bug? > > Thanks > _,_ > Hoang First, I’d say in the long run, you’re still better off looking into the FEC API. Right now, you’ll have to build the new manual yourself as we don’t have it published yet online, but the Forward Error Correction section in the new manual explains how you could build a deployment to use the FEC codes you need. Then, you wouldn’t have to have a patch on an existing block. That having been said, the FEC API is brand new, so there’s not much more help or examples than what’s in the manual and in the code right now. So we should at least be able to get you going with where you are now. Most likely, the problem is in the constructor of the block you’re editing. Look for the io\_signature line. You’ll see a ‘sizeof(float)’ there. Change that to ‘sizeof(char)’ and that should work for you. Tom