Raspberry Pi Winlink client over 2m VHF using Pat/wlk2-go + Direwolf + ax25 (not working yet)

Some rough notes on getting this combination working. This is my first attempt in getting the Pat / wlk2-go Winlink client working on a Raspberry Pi. I’m using:

• Direwolf as a packet soundcard modem
• ax25 as the connection between the Pat Winlink client and Direwolf
• a Rigblaster Advantage, as a USB soundcard interface between the Raspberry Pi and a 2m transceiver (an Icom ID-880H)

I already have Direwolf and ax25 networking configured from using my Pi as a Packet radio client (search for my previous blog posts on Direwolf and you’ll find my notes for installing and configuring). Following the instructions in the Pat wiki here, I added a new ax25 interface as a new line to the end of my /etc/ax25/axports files:

wl2k KK6DCT 0 255 7 2m winlink

The wl2k alias for the new port I think is the default that Pat looks for to connect.

Note: I already have Direwolf configured with a 1200 port for VHF packet so I reused this as my first test, but if you configure a 300 port for HF and then connect the Rigblaster to an HF radio, I think the setup will be much the same (I haven’t tried this yet, but this will be my next test).

Next I installed golang on the pi with:

sudo apt-get install golang

and then installed Pat with:

go get github.com/la5nta/pat

go get failed initially with $GOPATH not set. So I created go-workspace in my home dir, and then did

export GOPATH="$HOME/goworkspace"

and added this export to my .bashrc so it will be set next time I log on too.

Now the go get started downloading to goworkspace, but it seemed to hang before it completed. Alternatively, you can download a prebuild .deb file from the Pat github releases page and install with (I used this approach instead):

sudo dpkg -i pat_0.1.5_linux_armhf.deb

pat configure – opens an editor for the config file. I added my callsign in mycall, my winlink password.

To add an alias in the configuration for a connection via ax25, I added a connection to KG6SJT-10, which is my closes Winlink gateway on 2m:

“connect_aliases”: {
“KG6SJT-10”: “ax25:///KG6SJT-10”,
“telnet”: “telnet://{mycall}:CMSTelnet@server.winlink.org:8772/wl2k”
}

pat http – starts the web interface

From the web gui at localhost:8080 you can select the Connect menu item, select the alias added in the config above, but this blew up Pat when I tried it. Time to log a ticket:

2016/09/07 00:20:53 Connecting to KG6SJT-10 (ax25)…
fatal error: unexpected signal during runtime execution
[signal 0xb code=0x1 addr=0x0 pc=0x76f3d774]

runtime stack:
runtime.throw(0x5d0948, 0x2a)
/opt/go/src/runtime/panic.go:547 +0x78
runtime.sigpanic()
/opt/go/src/runtime/sigpanic_unix.go:12 +0x44

goroutine 53 [syscall, locked to thread]:
runtime.cgocall(0x457ff0, 0x10c6b7e4, 0x0)
/opt/go/src/runtime/cgocall.go:123 +0x11c fp=0x10c6b7c4 sp=0x10c6b7ac
github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25._Cfunc_ax25_aton_entry(0x0, 0x10ed00b0, 0x0)
??:0 +0x38 fp=0x10c6b7e0 sp=0x10c6b7c4
github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25.(*ax25Addr).setPort(0x10ed00a0, 0x10b5a250, 0x4, 0x0, 0x0)
/home/martinhpedersen/go/src/github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25/ax25_linux.go:361 +0x64 fp=0x10c6b7f0 sp=0x10c6b7e0
github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25.DialAX25Timeout(0x10b5a250, 0x4, 0x10b5a158, 0x6, 0x10d107cd, 0x9, 0x7a358200, 0xa, 0xcb8e4, 0x0, …)
/home/martinhpedersen/go/src/github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25/ax25_linux.go:136 +0x16c fp=0x10c6b984 sp=0x10c6b7f0
github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25.Dialer.DialURL(0x7a358200, 0xa, 0x10d108d0, 0x0, 0x0, 0x0, 0x0)
/home/martinhpedersen/go/src/github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25/ax25.go:114 +0x278 fp=0x10c6ba8c sp=0x10c6b984
github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/ax25.(*Dialer).DialURL(0x7c39f8, 0x10d108d0, 0x0, 0x0, 0x0, 0x0)
<autogenerated>:1 +0xb8 fp=0x10c6baac sp=0x10c6ba8c
github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport.DialURL(0x10d108d0, 0x0, 0x0, 0x0, 0x0)
/home/martinhpedersen/go/src/github.com/la5nta/pat/vendor/github.com/la5nta/wl2k-go/transport/dial.go:29 +0xbc fp=0x10c6bad4 sp=0x10c6baac
main.Connect(0x10d107c5, 0x11, 0x0)
/home/martinhpedersen/go/src/github.com/la5nta/pat/connect.go:108 +0x7b4 fp=0x10c6bc5c sp=0x10c6bad4
main.ConnectHandler(0x76457918, 0x10c1b200, 0x10bf8230)
/home/martinhpedersen/go/src/github.com/la5nta/pat/http.go:357 +0x68 fp=0x10c6bca8 sp=0x10c6bc5c
net/http.HandlerFunc.ServeHTTP(0x6208b4, 0x76457918, 0x10c1b200, 0x10bf8230)
/opt/go/src/net/http/server.go:1618 +0x34 fp=0x10c6bcb8 sp=0x10c6bca8
github.com/la5nta/pat/vendor/github.com/gorilla/mux.(*Router).ServeHTTP(0x10a114a0, 0x76457918, 0x10c1b200, 0x10bf8230)
/home/martinhpedersen/go/src/github.com/la5nta/pat/vendor/github.com/gorilla/mux/mux.go:107 +0x250 fp=0x10c6bd44 sp=0x10c6bcb8
net/http.(*ServeMux).ServeHTTP(0x10a0ea80, 0x76457918, 0x10c1b200, 0x10bf8230)
/opt/go/src/net/http/server.go:1910 +0x164 fp=0x10c6bd70 sp=0x10c6bd44
net/http.serverHandler.ServeHTTP(0x10a75680, 0x76457918, 0x10c1b200, 0x10bf8230)
/opt/go/src/net/http/server.go:2081 +0x190 fp=0x10c6bda0 sp=0x10c6bd70
net/http.(*conn).serve(0x10b841c0)
/opt/go/src/net/http/server.go:1472 +0xee4 fp=0x10c6bfcc sp=0x10c6bda0
runtime.goexit()
/opt/go/src/runtime/asm_arm.s:990 +0x4 fp=0x10c6bfcc sp=0x10c6bfcc
created by net/http.(*Server).Serve
/opt/go/src/net/http/server.go:2137 +0x3bc