[aprssig] HamHUD II Kit Group Buy In Progress

Jason Rausch jason at ke4nyv.com
Sun Jun 10 14:34:25 EDT 2007

--- Stephen - K1LNX <k1lnx at k1lnx.net> wrote:

> Are existing Hamhud II's able to be upgraded to
> include KISS support? 


> Was this just a firmware change?

Yes and no.  You will be able to upgrade by purchasing
a PIC18F2525 processor.  This is a pin for pin drop in
replacement of the current PIC18F252.  The only
difference is, the 2525 has more on-board RAM and
program space.  This is what we needed to have enough
buffering for the KISS function.

Also, since we have more buffering space, we do not
have to worry about using the RTS line to hold-off the
TNC and cause the HamHUD to "choke" on packets comming
in too fast.  For this reason, we are able to re-use
the RTS line for waypoint output to a mapping GPS. 
Better known as the "Anti-Tracker" function.  Since
this line was already ran through the on-board MAX202,
the end user can simply disconnect this line from the
RTS line of the TNC and re-wire it to the receive pin
of their GPS.  If you have one of my Breakout Boards
(http://www.rpc-electronics.com/hhacc.php) you can
simply re-jump the serial jumper setting to the WP
side of the three pin header.  This re-routes this
line to pin three of the GPS port.

Jason KE4NYV - HamHUD Development Team

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