[aprssig] poor man's blue tooth

David brozgrimm at hotmail.com
Wed Aug 4 14:46:21 EDT 2004

One thing that needs to be looked for legality at is the legality of  
using these modules for streamed data.  It's been a while since i last  
looked at the rules, but as I recall, Part 15 unlicensed operation  
requires that the transmission cycle be no more than 1/10 of the time;  
it's meant for short burst communuication and not continuous streams of  

Now, if you meant to use these as amateur transmitters, it'll need the  
10 minute idenfication as well as a reduction from 8-bit ASCII to 7-bit  
ASCII (according to  
305.html#309, only 7-bit ASCII is permitted), both of which will  
require more smarts than just RS232 level translation.


Message: 4
Date: Tue, 03 Aug 2004 15:32:33 -0400 (EDT)
From: wes at johnston.net
Subject: [aprssig] poor man's blue tooth
To: aprssig at lists.tapr.org
	<20040803123233.22322.h016.c000.wm at mail.johnston.net.criticalpath.net>
Content-Type: text/plain; charset=iso-8859-1

Although one of the arguements against blue tooth enabled GPS units is  
that you
just have that many more batteries to replace... consider this...

I'm thinking of two uses..
1)I have a GPS unit in my car and want to stream the GPS data to a  
laptop without
having to have a tangle of wires.  My GPS is already wired to a d700.

2)In an emergency comms bus, I want to have the ability to share GPS  
and TNC data
with other users.  I don't need them to be able to talk back, just to  
see what's
going on around them.

I think a neat "one to many" solution is Linx Technologies LC 433mhz rf  
The modules are simple 433mhz radios with serial in / serial out.  The  
TX module
is $5.60 in onesies, RX module is $11.80.  These modules TX at 5kbps at  
a range
of 300 feet.  All we need is to add them to a PCB with will do the  
level conversions and Y GPS data and TNC data together (on the TX  
side).  Give
each person/laptop you want to beable to see what is going on a RX  
module with
rs232 or they have a rs232 to USB module for $10.  Now you can "stream"  
data out
of the em comm bus to a public display (in the case of a publicity show  
and tell)
or even share a GPS between two cars which are following each other....  
or pass a
laptop around the inside of car w/o wires.



I have seen the village...
    and I don't want it raising my children.

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