Packet Radio: AX25, Direwolf and Linpac on a Raspberry Pi

I’ve been playing around trying to get a working config for using Direwolf as a soundcard modem for packet radio on the Raspberry Pi. I’ve played with getting ax25 and Direwolf running on Ubuntu (see here), and then I tried to copy across what I’d learnt to the Pi (running Raspbian).

The trouble with a lot of this stuff is there’s not much in the way of docs (although the Direwolf docs are really good), so when things don’t work you either start trying stuff randomly or just get stuck. Anyway, here’s the combination I have working:

  • Raspberry Pi (v1 model B) running Raspbian
  • RigBlaster connected via USB, connected to an Icom 880h
  • soundlevels at around 3/4 via alsamixer
  • Per ax25 on CentOS here, I used the ax25 sources from VE7FET’s github repo, compiled and installed

Most of my steps are the same as from my prior experience getting Direwolf and Linpac working on Ubuntu, so follow those steps if you’re looking to get setup, and then I’ve summarized the differences here.

The VE7FET source when you ‘sudo make install’ creates config files to /usr/local/etc/ax25 and not the default location of /etc/ax25. I’m not sure if Linpac likes this, so per a posting I found somewhere, the quick way to keep everyone happy is just create a symlink:

cd /etc/
sudo ln -s /usr/local/etc/ax25 .

Edit the axports file, add a line like:

1 KK6DCT-2 38400 253 2 2m packet

‘1’ is the portname

On the Pi I did run into the kissattach issue getting the ‘error setting line discipline’ error as described in the direwolf docs. Per the docs, I used the second of the workarounds:

sudo /usr/sbin/kissattach /dev/ptmx radio


sudo mkiss /tmp/kisstnc /dev/pts/5

where the /dev/pts/5 value is returned from the kissattach step.

At this point I’m ready to go:

‘call 1 kberr’ opens a connection to my nearest node (using port 1)

And also Linpac starts up (with linpac -m), can can connect the same there with ‘:c kberr’

At some point I should probably walk through these steps with a fresh Raspbian install to confirm I didn’t change anything else along the way that was key to getting this to work, but I think this summarizes the key points.

A few other helpful points:

  • in the Mac Terminal app by default, the Alt key doesn’t work so can’t do a Alt-X to exit Linpac. There’s a tip here to enable the Option key as Alt so you can use this to cleanly exit Linpac.

Is it worth running Windows just to use Ham Radio Deluxe?

I spent some time over the weekend using Ham Radio Deluxe running on an HP Mini netbook, and came to the conclusion that the netbook doesn’t really have enough horsepower to give a good experience with HRD. It’s just too sluggish opening the apps and moving back and forward between the Log app and the DM780 digital modes app. I did enjoy having the ability to automatically log my QSOs though, so I’ve spent some more time to investigate how I can make better use of the apps I’ve been using up until now on my Mac.

Turns out that RUMLog will watch the log files from FLDIGI and automatically copy new logged QSOs across from FLDIGI, so this is a good step in the right direction. For JT65-OSX, although it’s not automated, it will write to an ADIF file and then you can import that into RUMLog manually, so that’s better than nothing.

Sorry HRD, you’re just too bloated and I’m not interested in buying a new Windows machine just to run you. For now I think I’m going back to the apps I was already using on my Mac. Turns out RUMLog is actually pretty good 🙂

Ham Radio Deluxe 5.24 – PSK macros won’t save

As a Mac user and a new ham operator starting to play with digital modes (mainly JT65, PSK31 and RTTY) I’ve been envious of the variety of Windows based apps available compared to what’s available on the Mac. For the past few weeks I’ve been mainly using the following:

These have all been working fine, but from seeing videos online of people using HRD and the integrated digital mode app together with the HRD logging, it kept bothering me every time I had to manually type in details from a QSO into my logging app.

Since we have a HP Mini netbook running Windows 7, I decided to check out the still (up until fairly recently) free version of Ham Radio Deluxe (5.24), and was surprised to find I couldn’t work out how to make my updates to my PSK macros save. Every time I made changes in the Macro Manager, they would never be reflected in the app.

It turns out that from a new installation, HRD either protects the directory where your macros files are saved, and/or installs the default macro files as read-only, so no matter what you do in the app, you can never save any updates to your macro files. What’s worse, the app doesn’t give any indication that it’s failing to save your updates, it just carries on regardless.

Luckily I can across  this thread and once I took off the r/o flag on the macro files I was able to save my edits.

Now that HRD 6.x+ is $100, I’m not sure if I’m that enthusiastic about spending $100 on an app that doesn’t by default allow me to customize my preferences, and worse still, doesn’t tell me when something is failing (incorrect permissions to write to a file). Still, I am impressed with the digital modes and log integration, so I’m going to be trying it out for a while and see how it goes.