HOW TO BUILD GR-GN3S
----------------------
Source maintainer:
Javier Arribas
jarribas@cttc.es

This document describes how to build the GN3S V2 GPS Sampler GNU Radio Source USB 2.0 driver. 

More information on the device (not available anymore) can be found in http://www.sparkfun.com/products/8238

The driver core is based on Gregory W. Hecker driver available in http://github.com/gps-sdr/gps-sdr.

GR-GN3S contains a GNU Radio fully compliant gr-block signal source intended to be used either with GNSS-SDR as a signal source or as 
standalone signal source block instantiated from a GNU Radio flowgraph from C++ or using Python (Also includes a gnuradio-companion interface).

It is based on the GNU Radio How-to-make-a-block cmake source v 3.6

Installation in Ubuntu 11.04, 11.10, 12.04 (32 and 64 bits)
-----------------------------------------------------------

1- Install CMake through your OS's package manager or by some other means.

2- Install GNU Radio:

- Downloading, building and installing GNU Radio and all its dependencies is not a simple task. We recommend to use Marcus Leech's build-gnuradio script, which automatically does all the work for you. In a terminal, do:

$ wget http://www.sbrac.org/files/build-gnuradio
$ chmod a+x build-gnuradio
$ ./build-gnuradio

This can take a while (up to two hours to complete, depending on your system), and installs the latest versions of UHD and GNU Radio in your system, including all their dependencies. In case you do not want to use the script and prefer to build and install GNU Radio manually from source, follow instructions in http://gnuradio.org/redmine/projects/gnuradio/wiki/BuildGuide


3- Install Subversion

$ sudo apt-get install subversion

4- Check out the latest version of GNSS-SDR

$ svn co http://svn.code.sf.net/p/gnss-sdr/code/trunk gnss-sdr

5- Build GR-GN3S

- Go to GR-GN3S root directory and compile the driver:

$ cd gnss-sdr/drivers/gr-gn3s
$ cd build
$ cmake ../
$ make

6- If everything went fine, install the driver as root

$ sudo make install
$ sudo ldconfig

7- Open gnuradio-companion and check the gn3s_source module under the GN3S tab. 
In order to gain access to USB ports, gnuradio-companion should be used as root.
In addition, the driver requires access to the GN3S firmware binary file. 
It should be available in the same path where the application is called.
GNSS-SDR comes with a pre-compiled custom GN3S firmware available at gnss-sdr/firmware/GN3S_v2/bin/gn3s_firmware.ihx. 
Please copy this file to the application path.

8- Once the GR-GN3S driver is installed, you can add this Signal Source at gnss-sdr by doing:

$ export GN3S_DRIVER=1
$ bjam release



