[GPS_Standard] New System Fun

[k7hbg at dslextreme.com]

Hi everybody;
 My "ZAZ" system is still locked after about 24Hrs. I guess that I'll call
it operational. Now for the fun part. You know... the "fiddeley bits" and
add on thingies.
 There are now two items in the unit that can talk RS232 and so, a switch
to allow communications with both of them is needed. I decided to use a
couple of chips to form a "muxer" just before the MAX232 converter to
switch between the receiver and the controller. It works really well and
has the added benefit of being "fail safe" in that it always is connected
to the controller unless switched to the GPS receiver. Neat and pretty.
 The next thing I came up against is that if the unit is powered on and
connected to the PC. when turning on the PC., the com port fails. I'm
using Windows-xp.
 I decided to de-activate the MAX232 converter unless a PC is hooked to it
and powered on. This converter chip does not have an enable pin but the
MAX242 IC does and with only 2 more pins in that package it should fit on
the perf board I'm using just fine, Digi-Stuff has them and a couple are
on the way.
 I decided that I'll also use a little LCD display with a controller chip
to pick up and display some info from both the receiver and the
controller units.
 With many thanks to Graham / KE9H for his help I was pointed in the
direction of among others, the TAC32 com software. Works just dandy. He
had pointed out to me that the Oncore+ receiver need a bit of talking to
to persuade it to output streams of data.
 Looks like I'll have to discover what data the com program sends to the
receiver to get it perking.
 If anybody can steer me in the right direction for this info I'd be most
appreciative!
Best Regards to all and Hoppy Easter!
 Bob K7HBG