July 2009
The OpenWrt/X-Wrt AX.25 Project
For quite some time (some of the Seattle WETNET gang will say 'forever') I've been working on adding AX.25 support to embedded devices like your typical home router. Originally using the software from the OpenEmbedded project but eventually settling on OpenWrt and it's companion web interface X-Wrt.
The OpenWrt/X-Wrt AX.25 Project allows any router supported by OpenWrt to use the amateur radio AX.25 protocol. The core AX.25 tools and applications turn your router (along with a tnc and radio) into a TCP/IP capable packet system, a version of Digi_Ned makes it a smart digipeater while aprsd gives it the ability to be an APRS Internet gateway (igate).
All of it configurable through a handy web interface.
Configuring via the Command Line
If you don't wish to use the web configuration screens you can hand edit the required configuration file using a ssh connection to the router and the VI editor that is built-in to the images. Just use your favorite ssh client (openssh or putty) and open a ssh connection to the routers address. The user name is 'root' and the password is whatever you set when you initially setup the router.
Obtaining the images
Their are two ways to obtain images for flashing.
- Download pre-compiled images from here. If your device is supported then you can skip this section and go on to the section on flashing the image.
- Roll your own image for a device for which pre-compiled images don't exist.
Complete directions on building your own images is beyond the scope of this site, but we can offer a few hints to help point the way.
Infinity and Beyond
What else is possible - our ToDo list (in no particular order)
- Support for aprx a receive only APRS gateway
- smart selection of serial ports via a drop-down list
- ampr.org gateway scripts
- openvpn ampr.org gateway instructions
- ???
APRSD the APRS Internet Gateway
Again, like the digi_ned screen the aprsd screen should be self-explanatory.
The APRS Passcode is needed if you wish to enable gating from the Internet to RF, if not you may leave
it blank.
Digi_Ned smart aprs digi-peater
The digi_ned configuration screen should be self explanatory for most normal digi-peater operation.
If you have a complex configuration or you don't follow the WIDEn-n format used in the Pacific NorthWest
you can edit the raw digi_ned configuration file thru the link at the bottom of the screen
Basic AX.25 - Port and IP Protocol setup
The AX.25 configuration screen allows you to configure up to four individual serial ports for connection to KISS compatible TNC's
Use the line near the top to select which port you wish to configure.
- Note: Configure the ports in sequence, attempting to skip a configuration may cause problems since Linux assigns port names
(ax0, ax1, etc.) in order of creation.
Flashing the devices - and booting the first time
WARNING - While most flashing operations are recoverable you could potentially turn your router into an expensive brick
Linksys NSLU2
- Use this binary image for both Windows and Linux
- Put the NSLU2 in Upgrade Mode
- Upgrading from a Windows box? Follow these instructions.
Configuring via the Web interface
There are three main configuration screens.
- AX.25 port configuration - required to enable connection to a KISS TNC
- digi_ned - The APRS digipeater.
- aprsd - The APRS internet gateway daemon
Each configuration screen has a link at the bottom that allows editing of the raw configuration file if necessarry
and unlike the normal OpenWrt/X-Wrt screens there is only a single button to submit and activate your changes.
