Changes between Version 5 and Version 6 of Tutorials/k0SDR/Tutorial05

Timestamp:

May 20, 2013, 6:08:24 PM (12 years ago)

Author:

nilanjan

Comment:

—

Tutorials/k0SDR/Tutorial05

@@ -135 +135 @@
  * The magnitude value of the fft bins are stored in binary format. The first entry of the db file is shown above. So when dumping the file contents the fft bins data is shown as consecutive ASCII representation of the binary floating point numbers. The 1st is 84B7C43E <==> 0.38421, the 2nd bin is 2146863D <==> 0.065563, etc...
 
- * To quickly visualize the data we can download and compile the following code.
+ * To quickly visualize the data we can download and compile the following code (it's also in the attachment).
 {{{
+nilanjan@console.grid:~/UHD$ wget http://www.orbit-lab.org/raw-attachment/wiki/Trials/GNURadio/OmfExperiment1/sq3_parse.cpp
+nilanjan@console.grid:~/UHD$ gcc sq3_parse.cpp -o sq3_parse -lsqlite3
+nilanjan@console.grid:~/UHD$ ./sq3_parse spectrum.grid.sq3 > db_dump.dat
+}}}
 
+* Parse the database file, load octave for a quick plot.
+{{{
+nilanjan@console.grid:~/UHD$ ./sq3_parse spectrum.grid.sq3 > db_dump.dat
+nilanjan@console.grid:~/UHD$ octave
+octave:1> w = dlmread('db_dump_1500.dat',',');
+octave:2> a = w(:,[9:136]);
+octave:3> imagesc([1:size(a,2)] , [1:size(a,1)] , 10*log(sqrt(a)/1000));
+octave:4> colorbar()
 }}}