Delbert Johnson wrote:
How does the IPAQ hook up to that Magellan 310? A friend
has the teletype GPS
software I can "try out" on my IPAQ
...Chrissi
Cozy Mk-IV 13B-turbo
www.CozyGirrrl.com
SNIP <<
The attached drawing is the pin out description for the 9pin DIN
connector
that is on the back of most PCs. I wired up my Garmin GPS 90 unit to
send
data to the PC by wiring up a DCE 9pin Female DIN connector. I can't
find
my Garmin manual but if I recall, it gave me the wire specs on the small
connector that comes out of the mounting housing. It looks like I used
three wires: Gnd, TXD, & RXD. These are all that are needed (typically)
unless the GPS unit or IPAQ are expecting handshaking signals. Note
that
the TXD pin on the GPS side must match the RXD pin on the PC or IPAQ
side
AND the RXD pin on the GPS must match the TXD pin on the PC/IPAQ side.
I originally wired my GPS up to communicate with my PC so that I could
upload new Airport data to the GPS. I recently tested the GPS
datastream
and received it just fine on the PC but not on the IPAQ. The problem
was
that the IPAQ cable is a DCE device designed to communicate to DTE
devices
like PCs. In otherwords, the TXD pin on the IPAQ and the GPS were pin 2
on
both units and the RXD pin was #3. In order to communicate one unit
must be
listening on the pin that the other is transmitting on.
If your going to use your Magellan GPS to communicate to the IPAC you
will
need to:
1. Locate the information on the wire harness for the Magellan.
2. Purchase a Male DB9 connector.
3. Wire the RXD, TXD and GND to the same pins as shown on the
attached
drawing.
In otherwords, you need to make it look like a PC (DTE - Data
Terminal
Equipment device)
If you want to use your Magellan GPS to communicate to a PC you will
need
to:
1. Locate the information on the wire harness for the Magellan.
2. Purchase a Female DB9 connector
3. Wire the RXD, TXD and GND to pins 3,2 and 5 respectively on
the DB9
connector.
In otherworks you need to make it look like the IPAQ (DCE - Data
Carrier
Equipment).
If you want to use your Magellan GPS on to communicate to both the PC
and
the IPAQ you will need to:
1. Choose and implement one of the above options.
2. Purchase an additional Male AND Female DB9 connector to be
used as a
CUSTOM gender mender.
3. Wire the GND to GND (pin 5), TXD to RXD, and RXD to TXD from
the Male
DB9 to the Female DB9
4. Use this converter to connect to whichever unit the cable made
in
step one does not work with.
The crossover gender mender forces one device to appear as a DCE and
the
other as a DTE. The DTE device is normally the device with the Male
connector (PC) and the DCE is the device with the female connector
(IPAQ).
The nice thing about RS232 connections is that you can mess up the
wiring
and you won't hurt anything. I need to wire up a gender mender in order
to
get my GPS to work with the IPAQ. There are gender menders out there but
they won't work because they don't cross over the TXD and RXD cables.
If
you can find one that comes apart you might buy the tool the pushes the
pins
out so that you can move them on one of the DB9 connectors.
Hopefully this will get you started.
I have been thru all of this. There is a standard DB9
interface adaptor that does reverse the tx and rx pins.
But this is not really a problem to accomplish the
reversal. One of the major problems is that you need an
RS-232 converter that changes the voltage levels between
a PDA and a PC. There is a standard chip that does that
and that is what the RSS-232 adaptor cable for the PDA's
have within it in order to communicate as well as
reversing the pins.
I was unable to buy the HIROSHA plug for my Casio so
spent the $30 and cut the plug off to use. I then also
bought an M12 Motorola GPS And connected its TX/Rx pins
to the Casio thru my $30 plug. I was also able to get
3.2 volts from the Casio Rs232 port to power the GPS
either from the PDA battery or 5 Volt PDA power; so
there are no extra wires. The M12 chip/board is quite
small and only uses about 75 milliamps of current. It
uses a small external antenna. Its only drawback is that
is defaulted to BINARY output rather than NMEA. So.....
One needs a terminal program to communicate in
binary/text to switch it to NMEA. There is an onboard
battery in the GPS that maintains this NMEA output. But
in about 2 months of nonuse, the little battery goes
dead and we are now back to Binary output and NMEA based
Nav software will not work with this. I connect my
board to my PC thru an external RS232 Chip to switch it
back. I have a terminal program in my Casio but have
not been able to come up with the correct sytax to make
the M12 respond. It coould have some to do with the CF
and CR characters. A palm base computer terminal
program will work on this to switch the output to NMEA.
I just don't know what I am doing yet and have not spent
enough time to figure it out.
There are also some Casio PDA In-Car Holders that have a
built in RS232 chip and telephone jack (and power pug)
that can connect to a DB9 plug and to any type GPS
receiver. It mates up to the Casio withit built-in plug
similar to a cradel
Of course, there are the CF GPS types (flash card) that
circument all of these problems for about $200 and work
with all the WinCE PDAs.
My Casio is fine in a car but rather dim in an open
cockpit biplane.
HAL--
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. Copyright 1998-2002 All world wide rights reserved.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org