Raspberry PI2 as coding/decoding computer hardware

The Raspberry PI2 (RPI2) is a very nice, small and powerful little computer. It is capable of doing all the DSP tasks to decode and code the audio signals to and from the SDR hardware. I managed to install QUISK on the RPI2 and it runs very nicely. I am thinking of adding a touch screen display, to make the whole SDR transceiver a stand-alone unit, instead of having to hook up a desktop PC or laptop to it. Anyway, for my own reference, and for everyone else who is interested, I recorded all the steps necessary to install the software and get it running. Unlike windows, installing applications in a Linux environment is never straightforward.

I started with a clean image of Raspian Jessie, which supports all the new features introduced with the model 2 of RPI.
The latest images can be downloaded from the raspberrypi.org site HERE

Then, downloaded latest version of Quisk (version 4.0.3), to be found HERE

The software comes as an archive file (tar.gz), which needs to be unpacked. It doesn’t really matter where you place it. I unpacked it directly in the PI home directory (/home/pi).

The software is written in Python. Python version 2.7 must be installed to be able to run this. This is part of the Raspian image, so that is OK. But it also requires some additional software. Before setting up quisk, these need to be installed. I found it easiest to use the apt-get command in a terminal window. You can also use the packet manager if you like.

NB: the following assumes that the RPI2 is in someway connected to the internet.

The following commands install these necessary add-ons:

sudo apt-get install python-wxgtk2.8
sudo apt-get install fftw3
sudo apt-get install python2.7-dev
sudo apt-get install fftw3-dev
sudo apt-get install libasound2-dev
sudo apt-get install libpulse-dev
sudo apt-get install portaudio19-dev

After that you have to setup the software using the following command:

sudo python setup.py install

To be able to run the software as a normal user, you have to enable the USB port for all users. This is done by adding a file with the following line to the directory

/etc/udev/rules.d:

SUBSYSTEM==”usb”, ATTR{idVendor}==”16c0″, ATTR{idProduct}==”05dc”, MODE=”0660″, GROUP=”dialout”

I saved the file as ‘local.rules’. A reboot is necessary to update the system.

Now there was one thing I had to do. For some mysterious reason the USB backend directory was not installed correctly. This results in an error message when trying to run quisk with USB support.

As root, I had to copy these from:

/home/pi/quisk-4.0.3/usb

to:

/usr/local/lib/python2.7/dist-packages/quisk/usb

Now it is just typing the command ‘quisk’ in a terminal window to start the program. If you’re happy with it, you can add a launcher with a nice icon to the desktop.

Previous versions needed manual modifying a configuration file, but from version 4 quisk features a config function, called up by the config button.