# Asking help about "gr-ieee802-11" **URL:** \ **Category:** GNU Radio\ **Created:** [April 7, 2014, 4:44pm UTC](https://www.ruby-forum.com/t/asking-help-about-gr-ieee802-11/240300 "2014-04-07T16:44:35Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Post date:** [April 7, 2014, 4:44pm UTC](https://www.ruby-forum.com/t/asking-help-about-gr-ieee802-11/240300/1 "2014-04-07T16:44:35Z")
hi I’m the beginner of gnu radio. I have already follow your step to install all dependencies. but when i do the “OFDM PHY” It said i should open “/examples/wifi\_phy\_hier.grc” in gnuradio-companion and build it but when i open it, one of the block (ID: header formatter) appear wrong. error messages: Param - Value(value): Value “ieee802\_11.wifi\_signal\_field()” cannot be evaluated: name ‘ieee802\_11’ is not defined I tried hard to find “ieee802\_11” and I found that folder, but still can’t find it by grc. as the pic in attachment. I also tried to install “gr-foo” and “gr-ieee802-11” by “cmake …” and by “cmake -D CMAKE\_INSTALL\_PREFIX=/opt/local …” My OS: MBPR OSX 10.9.2 Gnuradio Version: 3.7.3 I just want to make it work with “wifi\_lookback.grc” without any connection to usrp. thanks for your help. ---
**Author:** ![kevins86051](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@kevins86051](https://www.ruby-forum.com/u/kevins86051)\ **Post date:** [May 12, 2014, 3:34pm UTC](https://www.ruby-forum.com/t/asking-help-about-gr-ieee802-11/240300/2 "2014-05-12T15:34:29Z")
ChunHuai Fu wrote in post #1142154: > hi > > I’m the beginner of gnu radio. > > I have already follow your step to install all dependencies. > > but when i do the “OFDM PHY” > > It said i should open “/examples/wifi\_phy\_hier.grc” in > gnuradio-companion and build it > > but when i open it, one of the block (ID: header formatter) appear > wrong. > > error messages: > Param - Value(value): > Value “ieee802\_11.wifi\_signal\_field()” cannot be evaluated: > name ‘ieee802\_11’ is not defined > > I tried hard to find “ieee802\_11” and I found that folder, but still > can’t find it by grc. > > as the pic in attachment. Hi,plz did you find a solution to your problem.If yes plz can you show me how did you correct it ? > I also tried to install “gr-foo” and “gr-ieee802-11” by “cmake ..” and > by > “cmake -D CMAKE\_INSTALL\_PREFIX=/opt/local ..” > > My OS: MBPR OSX 10.9.2 > > Gnuradio Version: 3.7.3 > > I just want to make it work with “wifi\_lookback.grc” without any > connection to usrp. > > thanks for your help. Hi, plz did you find a solution to your problem ? If yes plz show me how did you correct it ---
**Author:** ![kevins86051](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@kevins86051](https://www.ruby-forum.com/u/kevins86051)\ **Post date:** [July 29, 2014, 10:06am UTC](https://www.ruby-forum.com/t/asking-help-about-gr-ieee802-11/240300/3 "2014-07-29T10:06:47Z")
It took me 2 days to figure this out. Recording here for other users who might stumble on this problem via the web. The primary problem is that the PYTHONPATH for the modules gr-ieee802-11 is not setup. By default the module gr-ieee802-11 is installed here /usr/local/lib/python2.7/site-packages (Check your install\_manifest.txt file located within your build directory to find the location of the files ieee802\_11/ **init**.py are…this is where the module is located) The second problem is that the default python version is 2.7.5 in /usr/bin/python while macports installs python version 2.7.8 for gnu radio-companion. So now there is a mismatch in python versions causing grc to crash. To fix this you need to change the python version used to build gr-ieee802-11. To do this the steps from before are: git clone git://github.com/bastibl/gr-ieee802-11.git cd gr-ieee802-11 mkdir build cd build cmake … STOP here. Look at CMakeCache.txt file. Change all instances of /usr/bin/python to the python version from macports For me macports python was in /opt/local/bin. Change python header files location, and change library files location. For me macports Header files was in /opt/local/Library/Frameworks/Python.framework/Versions/2.7/Headers Similarly library files is /opt/local/lib/libpython2.7.dylib Run cmake … again and ensure that CMakeCache.txt has not changed. Now continue the regular steps below make sudo make install Works for me… ---
**Author:** ![kevins86051](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@kevins86051](https://www.ruby-forum.com/u/kevins86051)\ **Post date:** [November 12, 2014, 4:12pm UTC](https://www.ruby-forum.com/t/asking-help-about-gr-ieee802-11/240300/4 "2014-11-12T16:12:18Z")
hey, thanks for reply it. but i can’t clearly figure out. what is “Change all instances of /usr/bin/python to the python version from macports”? is to modify the CMakeCache.txt file? or move two file (header files & library files) to somewhere? and how about “gr-foo” installation? install it as default? coz it will be install to /usr/local/… thanks so much!!