[OZAPRS] Computerless iGate

[Ian Pople]

Hi All,

A friend and I are looking at making up a few igates based on D-Link
DSL-502T as we saw someone else had managed to make one work.
See <http://groups.yahoo.com/group/ZLAPRS/message/2786>
You can see his status page here <http://www.technzl.com:14501/>
On our local (NZ) auction website Trademe.co.nz you sometimes see
these pop up with a low reserve of $10, like this one.
<http://www.trademe.co.nz/Browse/Listing.aspx?id=268166905>
Much cheaper than trying to find a WRT54G to play with.

The DSL-502T has a pair of serial ports available on pin headers at
the front right of the board, only slight issue is that it is all
3.3 Volt logic. But you can still make it work with a 5 Volt based TNC
using voltage dividers and a weak pull-up components.

As for a TNC, there is this design here
http://users.rcn.com/carlott/atmega-tnc.html
which uses an ATmega8 microcontroller, and a MX or FX614 modem IC.
It has some other weather station features and hardware, which we'll
leave out to keep it basic and easier to build.
The source code is included and well commented, so one can tinker
around and change things if need be.

As the design is fairly straightforward hardware wise, I was thinking
of doing a couple PCBs to fit inside the D-Links, and just run PTT, audio
in & out, out of the D-Link to a radio.
While this model of D-Link says 9VAC on the rear as a supply, it uses
a AP36063 to switch it down to 3.3 Volts, so some other supply voltage
should be ok too.

73,
Ian ZL1VFO