[Xastir] TNC setup problem

[Curt, WE7U]

On Mon, 4 Apr 2011, Jacob Tennant wrote:

>    I am using a KPC-2 TNC...
>
>    When I activate the TNC in Xastir with the tnc-startup.kpc2 file, I can
> not get the TNC to transmit properly for position or message packets?
> Looking at the Incoming data screen, every time the computer tells the TNC
> to transmit the TNC responds EH ? I did get a few message packets to go out
> but had to click the ³Kick the timer² button repeatedly but only a few of
> them got out without the EH ? showing up.

The key may be that you're running an older TNC and we may not have the commands for that one exactly correct in the setup file.  I'd compare the commands in that file and the ones Xastir sends for a transmit) to the manual for the TNC.  Edit the file or the code appropriately.  We can help once you figure out which commands it's choking on.

Sometimes the "EH?" response is ok from a TNC if it's just choking on one or two commands in the setup and depending on which commands they are.  If it's happening every transmit, it's probably one of the hard-coded commands in Xastir itself which will be a bit more difficult to fix.

The areas where we write out to a serial-mode TNC are:

     src/interface.c
         output_my_aprs_data()
         output_my_data()

port_write_string() is the function to look for.  Looks like we do this before each transmit:

     Control-C \r MYCALL <callsign>
     Control-C UNPROTO VIA <unproto path>
     Control-C <CONVERSE MODE>       # either "CONV" or "k"

Try typing those commands from a terminal emulator to see what the TNC chokes on.  It's probably the "CONV" or "k" command which is currently set to 'k'.  Switch to "CONV" in interface.h, recompile/reinstall, and try again.

Ah yes, the comments in interface.h specifically talk about a KPC-2, so change the code to look like this:

     // User configurable text for taking a TNC into converse mode.
     // Uncomment only one of the below two lines.
     //
     // Works for most TNC's, including tnc2-ui
     //#define CONVERSE_MODE "k"
     //
     // Works for Kantronics KPC-2
     #define CONVERSE_MODE "conv"

and recompile/reinstall.  That should fix your problem.


> Hoping to get Xastir running as I am in college for IT/IS degree and have a
> Linux class starting in the fall so I am trying to hit the Linux system hard
> to be ready since I am a 44 year old Sophmore... :)

Heck, you're just a young guy.  ;-)

-- 
Curt, WE7U.        http://www.eskimo.com/~archer
APRS Device Capabilities:  http://www.eskimo.com/~archer/aprs_device_capabilities.html