[aprssig] Quick and dirty weather

scott at opentrac.org scott at opentrac.org
Fri Apr 15 12:53:17 EDT 2005

The OpenTracker will poll the sensors it expects to find in the AAG station.
If it's missing any, it just doesn't report that data.  You could put just a
DS18S20 sensor on the bus, for example, and it'll only report temperature.
Of course, it'll do that if you don't plug anything in at all, but the
on-board sensor isn't as accurate.

It doesn't support any other sensors than the ones that come with the AAG
station so far.  It won't poll a humidity sensor or barometer, for example.
I'll work on those when I get time.  When you add more than one of the same
sensor type to the bus, things get more complicated because you've got to
uniquely identify each sensor.  If there's just one, it can identify it by

Scott, N1VG

-----Original Message-----
From: aprssig-bounces at lists.tapr.org
[mailto:aprssig-bounces at lists.tapr.org]On Behalf Of Ryan Tourge
Sent: Friday, April 15, 2005 9:41 AM
To: 'TAPR APRS Mailing List'
Subject: RE: [aprssig] Quick and dirty weather

Do you think this could be done with separate 1-wire sensors or does it have
to be a davis/aag station?

-----Original Message-----
From: aprssig-bounces at lists.tapr.org [mailto:aprssig-bounces at lists.tapr.org]
On Behalf Of Scott Miller
Sent: Friday, April 15, 2005 12:29 PM
To: TAPR APRS Special Interest Group
Subject: [aprssig] Quick and dirty weather

I've been running a 1-wire station off an OpenTracker off and on for a while
at my house, testing out solar charging setups and such.  Decided I wanted
to make it a permanent installation, but didn't want to devote another
antenna, radio, and power supply to the effort.

What I wound up doing was plugging a DB9 Y cable between the KPC-3 on my
IGate and the radio cable.  Jumpered the KPC-3 for external power, clipped
the PTT diodes on the tracker so it'd play nice, and plugged it in to the
other side of the Y.  Now they both use the same radio, and the KPC-3 powers
the OpenTracker without any extra wiring.  A few obvious deficiencies come
to mind:

1. No collision avoidance between the two
2. OpenTracker can't run open squelch
3. IGate can't hear the tracker

Number 1 isn't a big deal, since they both transmit infrequently.  Number 2
is annoying, but my IGate hears 99% of its traffic from a couple of WIDEs
and they've got long enough TXDs and strong enough signals that running open
squelch doesn't really help anything.  And as for number 3, it's running a
single-hop path, so the IGate hears the packet as it comes back from the

It's quick and dirty, but it's simple and it works.  Just a Y cable,
OpenTracker, 1-wire cable, and weather sensor unit.  I don't think this is
what Kantronics intended when they put in the external power jumper, but it


Scott, N1VG

aprssig mailing list
aprssig at lists.tapr.org

aprssig mailing list
aprssig at lists.tapr.org

More information about the aprssig mailing list