[Xastir] USER VISIBLE CHANGE FOR KENWOOD D7* users!

[Tom Russo]

If you are not using a Kenwood APRS radio (D700, D7, D72, D710) with Xastir,
you can ignore this note.  

I have just removed an ancient work-around that was put in place to address
an error when Xastir connected to a D700 using the "Serial TNC with GPS on 
AUX port" interface type.  In its place, I have put a proper fix.  But this
fix requires that you take action if you are using CVS Xastir and a Kenwood
radio.

If you're using a Kenwood radio with the "Serial TNC with GPS on AUX port"
interface type, and you update your Xastir with CVS after this note, you must
change one setting on the interface properties dialog.  
Open Interface->Interface Control, select your Kenwood interface, and choose 
the "Properties" button.  You will see that there is a new check box,
"Send Control-E to get GPS data?" --- deselect this checkbox and save the 
change. That's it, you're back in business.   

IF YOU FAIL TO MAKE THIS CHANGE, XASTIR MAY CAUSE YOUR TNC TO FAIL TO RECOGNIZE
the "MYCALL" COMMAND IT SENDS BEFORE EVERY POSITION REPORT.

I will update the wiki and the built-in help shortly.

Xastir users who use language files other than English are asked to provide
a translation for the dialog box --- right now, all other languages will
have this checkbox's label showing up in English.

If you really care what this change is all about, read on.

Six years ago, a number of Xastir users complained that every time they used
Xastir with their D700 radios using the "Serial TNC with GPS on AUX port"
interface type, the radio's TNC complained "EH?" every time Xastir transmitted
a posit, right when it sent its "MYCALL " line. 
   (Every time Xastir tranmsits a posit using a serial, non-KISS TNC, it first 
    sends a MYCALL command and then sends a UNPROTO command before entering 
    CONV mode and sending the actual posit.  By getting this error, Xastir
    could be causing the TNC to transmit a posit with the wrong call sign,
    especially if MYCALL had never before been issued --- the result would
    be a posit from NOCALL)

After several days of looking into it, we were unable to figure out what junk
Xastir was sending to the serial port that was confusing the TNC, but clearly
some junk was already in the buffer when Xastir sent the MYCALL, and this 
confused the TNC.  Just to get Xastir working properly with these radios, 
a hack was put into the Serial TNC code to send a carriage return right before
sending MYCALL, which would still cause the TNC to emit an "EH?" but would
let it accept the MYCALL.

This was, of course, a kludge, and should have been followed up with real
investigation of what garbage was getting into the buffer.  It only came back
a month or so ago when, on another APRS client's mailing list it was mentioned
that SOME TNCs that allow one to attach a GPS require one to send Control-E
to the TNC to get the GPS data, but most do not.  Guess what --- Xastir's
Serial TNC with GPS on AUX port was written to support one of those TNCs that
do require Control-E, but the D700 does not.  It took this other mailing list,
where a user was complaining that this client did NOT send control-E to his
device, to get the light to come on over this issue for me.

Not only does the D700 not require Control-E to get it to send GPS data, it
doesn't even read the Control-E.  Thus, by the time Xastir got around to 
sending a posit, it had usually sent several unnecessary Control-Es, and
when the MYCALL was sent, the control-e string made the tnc thing there was
an invalid command sent.


-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236        http://kevan.org/brain.cgi?DDTNM
"And, isn't sanity really just a one-trick pony anyway? I mean all you get is
 one trick, rational thinking, but when you're good and crazy, oooh, oooh,
 oooh, the sky is the limit!"  --- The Tick