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UDRC / DRAWS Raspberry Pi image

Provision the micro SD Card

Download the image file
  • Go to the download site to find the current filename of the image

    • You can get the image using the following or just click on the filename using your browser.

      Unzip the image file
Provision an SD card
  • At least a 16GB microSD card is recommended

  • If you need options for writing the image to the SD card ie. you are not running Linux go to the Raspberry Pi documentation page and scroll down to "Writing an image to the SD card"

  • For linux, use the Department of Defense Computer Forensics Lab (DCFL) version of dd, dcfldd.

    • You can ruin the drive on the machine you are using if you do not get the output device (of=) correct. ie. below /dev/sdf is just an example.
    • There are good notes here for Discovering the SD card mount point

      # You will find an image file: nwdrxx.img
      # Become root
      sudo su
      apt-get install dcfldd
      # Use name of unzipped file ie. nwdr14.img
      time (dcfldd if=nwdrxx.img of=/dev/sdf bs=4M status=progress; sync)
      # Doesn't hurt to run sync twice
  • The reason I time the write is that every so often the write completes in around 2 minutes and I know a good write should take around 11 minutes on my machine.

  • Boot the new microSD card

    login: pi
    passwd: digiberry

Initial Configuration

Initial Config Summary

  • First boot:
    • Verify that required drivers for the DRAWS codec are loaded
    • Follow 'Welcome to Raspberry Pi' piwiz screens.
    • Update the configuration scripts
  • Second boot: run script: core
  • Third boot: Set your ALSA config
  • For packet turn on Direwolf & AX.25

Check for required drivers first

  • First open a console and type:

    aplay -l
  • You should see a line in the output that looks something like this:

    card 0: udrc [udrc], device 0: bcm2835-i2s-tlv320aic32x4-hifi tlv320aic32x4-hifi-0 []
  • If you do not see udrc enumerated do not continue

Initial Config Detail

  • If you are running with an attached monitor you should see the Raspbian 'Welcome to Raspberry Pi' piwiz splash screen
    • Follow the screens as you would on any other Raspbian install.
    • When prompted to restart the RPi please do so.
Update configurations scripts
cd n7nix
git pull

sudo su
apt-get update
apt-get dist-upgrade
# revert back to normal user
Configure core functionality
  • Whether you want direwolf for packet functionality or run HF apps with the draws HAT do the following:
cd n7nix/config
# Become root
sudo su
./ core
  • The above script sets up the following:

    • iptables
    • RPi login password
    • RPi host name
    • mail host name
    • time zone
    • current time via chrony
    • AX.25
    • direwolf
    • systemd
  • Now reboot your RPi

  • You must set your ALSA configuration for your particular radio at this time

    • Also note which connector you are using as you can vary ALSA settings based on which channel you are using
    • On a DRAWS hat left connector is left channel
    • On a UDRC II hat mDin6 connector is right channel
    • You also must route the AFOUT, compensated receive signal or the DISC, discriminator receive signal with ALSA settings.
    • If you are using the setalsa_ scripts in your local bin directory run as root to save the configuration between reboots.
    • Verify your ALSA settings by running
  • verify your installation is working properly

  • NOTE: the default core config leaves AX.25 & direwolf NOT running & NOT enabled

    • The default config is to run HF applications like js8call, wsjtx and FLdigi
    • If you are not interested in packet and want to run an HF app then go ahead & do that now.
    • If you want to run a packet application or run some tests on the DRAWS board that requires direwolf then enable AX.25/direwolf like this:

      cd ~/bin
      # Become root
      sudo su
Reboot to enable packet
  • Now reboot and verify by running:

    ax25-status -d

More Packet Program Options

  • After confirming that the core functionality works you can configure other packet programs that will use direwolf such as rmsgw, paclink-unix, etc:
cd n7nix/config
# Become root
sudo su
# If you want to run a Linux RMS Gateway
./ rmsgw
# If you want to send & receive Winlink messages
./ plu

For HAM apps that do NOT use direwolf

  • If you previously ran a packet app and now want to run some other program that does NOT use direwolf like: js8call, wsjtx, FLdigi, then do this:
cd bin
# Become root
sudo su
  • This will stop direwolf & all the AX.25 services allowing another program to use the DRAWS sound card.

Enable the RPi on board audio device

  • The default configuration enables the RPi on board bcm2835 sound device
  • If for some reason you want to disable the sound device then:

    • As root comment the following line in /boot/config.txt
    • ie. put a hash character at the beginning of the line.

  • You need to reboot for any changes in /boot/config.txt to take effect

  • after a reboot verify by listing all the sound playback hardware devices:

    aplay -l

Make your own Raspberry Pi image

  • The driver required by the NW Digital Radio is now in the main line Linux kernel (version 4.19.66)
  • To make your own Raspberry Pi image
    • Download the lastest version of Raspbian from here
    • Choose one of:
      • Raspbian Buster Lite
      • Raspbian Buster with desktop
      • desktop and recommended software
  • Add the following lines to the bottom of /boot/config.txt

  • If you want to ssh into your device then add an ssh file to the /boot directory

    touch /boot/ssh
  • Boot the new micro SD card.