[Xastir-dev] Closing AUX GPS port before shutdown / down of interface

[Tom Russo]

On Fri, Jun 04, 2004 at 05:58:33PM -0700, a Mr. Richard Feyler of Fort Lee, New Jersey <davidf4 at mindspring.com> writes 'Dear Rosanne Rosannadanna':
> Hello all,
> 
> I've finally gotten fed up with having to do a VFO reset on my D700 when I
> switch back from computer control to internal brain dead APRS.  The problem
> is that if the AUX GPS port is left open or the internal TNC is expecting
> GPS data then the entire TNC locks up when you try to switch back to
> internal mode.
> 
> Is there a way, either in the stop file or in the internal code to ensure
> that when using the TNC with AUX GPS that the AUX GPS port is fully and
> properly closed before the interface is downed?

I don't know the answer to how to make Xastir do this, but you should never
have to do a vfo reset on the D700.  

The trick I learned was posted on the TMD700A yahoo group in this message:

   http://groups.yahoo.com/group/TMD700A/message/3207

The windows-oriented description (i.e. "start Hyperterm...") is easily adapted:
If you get hung in the "Opening TNC" mode when switching back to internal 
APRS mode:
1) connect directly to the D700 serial port from your computer (I use "cu" to 
do that)
2) type "TC 1" to get the radio into terminal control mode
3) type "GU 0" to shut off the GPS port
4) type "TNC 2" to switch into PKT mode
5) wait for "Opening TNC" to go away
6) type "TNC 1" to go back to internal APRS mode
7) type "GU 1" to turn the 4800 baud NMEA mode back on
Then shut off the radio, disconnect your computer and you should be back to 
normal in APRS mode with no reset needed.

The yahoogroups message ends this procedure with instructions to type "TC 0" 
to turn off terminal control mode, but IIRC it actually doesn't work --- TC 0 
appears only to turn off terminal control mode when in PKT mode, and just 
echos an error message in APRS mode.  YMMV.

Since learning this procedure I have never had to do a VFO reset to clear that
annoying D700 bug.  Prior to learning the procedure I had to do one every 
single time I hooked a computer up to my D700.

It could be that a similar combination of commands could prevent the "opening
TNC" hang in the first place.  I briefly experimented with inserting some of 
these commands into a TNC stop file for Xastir (for example, 'tc 1' followed by 
'gu 0' and 'tc 0' should shut down the gps port cleanly).
But I've  never had it actually work --- if I watch the data from the 
"View->incoming data" window I see the radio saying "Eh?" a lot instead of 
accepting the commands.   I think a few of these commands cause a delay as the 
TNC switches modes, and there's no obvious way to enforce a delay between 
command lines in the start and stop files.  I would be delighted to learn if 
someone else has figured it out.  In the meantime, since I only infrequently 
hook my D700 up to my laptop with xastir, the manual procedure has been good 
enough (and a damn sight better than doing a reset/reprogram of the radio!).

-- 
Tom Russo    KM5VY     SAR502  DM64ux         http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236 AHTB#1 http://www.qsl.net/~km5vy/
 "If life gives you lemonade, kick it in the balls and say 'Hey, I wanted 
  a beer.'"