There is now a pre build ready to go image available, also based on Jessie Light, fits onto a 4GB SD card and has an auto updater. Read the P25NX Google group or check the P25NX website for contact information. The way below is still valid, but as of now more effort than needed.
I am using Raspian Jessie Light , after the image is written to a SD card, start the Pi and run sudo raspi-config and expand the file system, reboot. Then enter sudo nano /etc/dhcpcd.conf and give eth0 a static address:
interface eth0 static ip_address=192.168.1.2/24 static routers=192.168.1.1 static domain_name_servers=192.168.1.1
The address is only an example, use the right one acording to the P25NX setup instructions. After you changed the address reboot the Pi. After this enter the following commands:
sudo apt-get update sudo apt-get upgrade sudo apt-get install git sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF echo "deb http://download.mono-project.com/repo/debian wheezy main" | sudo tee /etc/apt/sources.list.d/mono-xamarin.list sudo apt-get update sudo apt-get install mono-complete cd /opt sudo git clone https://github.com/p25nx/pnx-mono.git cd pnx-mono sudo xbuild /p:configuration=Release cd bin/Release mono pnx-mono.exe
After that you should be able to access the web interface via the Pis IP address on port 8080.
To update the p25nx-mono program, go to the pnx-mono directory cd /home/pi/pnx-mono and do a git pull https://github.com/p25nx/pnx-mono.git and run the xbuild command. After it’s finished use the last two commands to start the version that we compiled in the last steps.
For more information about the P25NX network visit the Homepage