[Xastir] HSP/AUX/Timings etc.

[Stephen West-Fisher]

Random comments about what I've noticed now that I've had the HSP 
interface up and running for a few days.

First, more of a comment about how I fixed it, and what is next. I did a 
very bad programmer thing (I've been known to get harsh with programmers 
who work for me and do this) and just copied another section of code, 
made a few little modifications, and it worked.

Looking at the code, it looks like the HSP stuff is an extention of the 
normal serial GPS stuff. However, it also appears a better use of code 
would be to treat the HSP code as an extention of the AUX code. In both 
HSP and AUX all data goes into the same buffer and is parsed from there. 
I'm going to give this a try when I get a chance.

Secondly, I'm still having the odd Segfault, but it may be my crappy 
code modification above. Origionaly I thought it was happening on the 
GPS strings, but this morning I had one on a digi of my beacon.

Third, the timing issue I had brought up earlier. I'm now not so sure it 
is a problem, but Curt's idea of a timeout when reading the GPS may be 
needed in the HSP code. Last night I was getting very frustrated because 
the DTR was getting stuck low no matter what I did. When I decided to 
give up for the night, I noticed the GPS had lost sync. So my theory for 
today is that when Xastir gets stuck with DTR low, the GPS has lost 
signal. I'm going to keep an idea on that for the next few days. While 
this is not then an Xastir problem (if it pans out) I do believe Xastir 
should be able to gracefully handle the situation. Currently, Xastir 
holds DTR low waiting for the GPS. On a serial port this isn't a 
problem, but on an HSP device it is blocking the reception on the TNC. 
Not a good thing. So a time-out to raise DTR high to listen to the TNC 
until the next GPS sample time would be a good idea.

-- 
Stephen West-Fisher
Coastal Data Systems
727.418.9774
http://www.coastaldatasystems.com/