Motorola Oncore GPS Engine for $14.95

Robert Donnell seatcp@wetnet.net
Wed, 25 Sep 2002 15:22:04 -0700


This is a multi-part message in MIME format.

------=_NextPart_000_0037_01C264A7.7ACA27A0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit

RS-232 voltage levels are defined as being +/- 3 volts to +/- 25 volts -
that's plus AND minus.

TTL voltage levels are defined as 0 to 1.5 volts for a zero, 2.5 to 5 volts
for a one, approximately.  No negative voltage allowed.

The MAX23x series chips provide sections internally to do the voltage
conversions both ways, with the main differences in the family being the
number of converters in each direction (RS-232->TTL and TTL->RS-232) and
whether external capacitors are needed for the built-in charge-pump power
supply that takes its 5-volt input and generates about +/- 10 volts to
supply the RS-232 line drivers.

However as Bill suggests, if the GPS engine is to be connected to a Tiny
Trak, you may be able to make the connection directly, or you may need to
put an inverter (either IC or transistor) in the  line from the GPS to the
Tiny Trak.

Does that help?

73, Bob

-----Original Message-----
From: seatcp-admin@wetnet.net [mailto:seatcp-admin@wetnet.net]On Behalf
Of Eric Johanson
Sent: Wednesday, September 25, 2002 2:31 PM
To: seatcp@wetnet.net
Subject: Re: Motorola Oncore GPS Engine for $14.95


After a closer look, I think I may have to retract my prior statements.

http://www.bgmicro.com/pdf/acs1397.pdf

It talks about needing to build a 'serial' interface, using a "MAX233"
chip.   This is strange, as most of the garmin units I've worked with have
direct serial output.  Maybe that's why this is only $15.

On the flip side, it does list the 10pin connector as including "RS232
interface signals", listing pins 8 & 9 as being TTL TX & RX.  I'm really
confused at this point.   :)

Can anyone provide some clarity?

Thanks,
Eric

On Wed, 25 Sep 2002, Ricky Scott wrote:

>
> >
> > Read a pinout, find the serial TX, RX & GND, solder
> > it to a DB9/DB25
> > cable.  Find power.  Apply power without letting the
> > factory smoke out.
>
>
> Thats Advanced ?, man I wonder what simple would be.
> I think I can do that sleeping or at least dosing :).
>
>
> Scotty N7HJ
>
> __________________________________________________
> Do you Yahoo!?
> New DSL Internet Access from SBC & Yahoo!
> http://sbc.yahoo.com
> _______________________________________________
> Seatcp mailing list
> Seatcp@wetnet.net
> http://wetnet.net/mailman/listinfo/seatcp
>

_______________________________________________
Seatcp mailing list
Seatcp@wetnet.net
http://wetnet.net/mailman/listinfo/seatcp

------=_NextPart_000_0037_01C264A7.7ACA27A0
Content-Type: text/html;
	charset="us-ascii"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; =
charset=3DWindows-1252">
<META NAME=3D"Generator" CONTENT=3D"MS Exchange Server version =
6.0.5762.3">
<TITLE>RE: Motorola Oncore GPS Engine for $14.95</TITLE>
</HEAD>
<BODY>
<!-- Converted from text/plain format -->

<P><FONT SIZE=3D2>RS-232 voltage levels are defined as being +/- 3 volts =
to +/- 25 volts - that's plus AND minus.&nbsp; </FONT>
</P>

<P><FONT SIZE=3D2>TTL voltage levels are defined as 0 to 1.5 volts for a =
zero, 2.5 to 5 volts for a one, approximately.&nbsp; No negative voltage =
allowed.</FONT></P>

<P><FONT SIZE=3D2>The MAX23x series chips provide sections internally to =
do the voltage conversions both ways, with the main differences in the =
family being the number of converters in each direction (RS-232-&gt;TTL =
and TTL-&gt;RS-232) and whether external capacitors are needed for the =
built-in charge-pump power supply that takes its 5-volt input and =
generates about +/- 10 volts to supply the RS-232 line =
drivers.</FONT></P>

<P><FONT SIZE=3D2>However as Bill suggests, if the GPS engine is to be =
connected to a Tiny Trak, you may be able to make the connection =
directly, or you may need to put an inverter (either IC or transistor) =
in the&nbsp; line from the GPS to the Tiny Trak.</FONT></P>

<P><FONT SIZE=3D2>Does that help?</FONT>
</P>

<P><FONT SIZE=3D2>73, Bob</FONT>
</P>

<P><FONT SIZE=3D2>-----Original Message-----</FONT>

<BR><FONT SIZE=3D2>From: seatcp-admin@wetnet.net [<A =
HREF=3D"mailto:seatcp-admin@wetnet.net">mailto:seatcp-admin@wetnet.net</A=
>]On Behalf</FONT>

<BR><FONT SIZE=3D2>Of Eric Johanson</FONT>

<BR><FONT SIZE=3D2>Sent: Wednesday, September 25, 2002 2:31 PM</FONT>

<BR><FONT SIZE=3D2>To: seatcp@wetnet.net</FONT>

<BR><FONT SIZE=3D2>Subject: Re: Motorola Oncore GPS Engine for =
$14.95</FONT>
</P>
<BR>

<P><FONT SIZE=3D2>After a closer look, I think I may have to retract my =
prior statements.</FONT>
</P>

<P><FONT SIZE=3D2><A =
HREF=3D"http://www.bgmicro.com/pdf/acs1397.pdf">http://www.bgmicro.com/pd=
f/acs1397.pdf</A></FONT>
</P>

<P><FONT SIZE=3D2>It talks about needing to build a 'serial' interface, =
using a &quot;MAX233&quot;</FONT>

<BR><FONT SIZE=3D2>chip.&nbsp;&nbsp; This is strange, as most of the =
garmin units I've worked with have</FONT>

<BR><FONT SIZE=3D2>direct serial output.&nbsp; Maybe that's why this is =
only $15.</FONT>
</P>

<P><FONT SIZE=3D2>On the flip side, it does list the 10pin connector as =
including &quot;RS232</FONT>

<BR><FONT SIZE=3D2>interface signals&quot;, listing pins 8 &amp; 9 as =
being TTL TX &amp; RX.&nbsp; I'm really</FONT>

<BR><FONT SIZE=3D2>confused at this point.&nbsp;&nbsp; :)</FONT>
</P>

<P><FONT SIZE=3D2>Can anyone provide some clarity?</FONT>
</P>

<P><FONT SIZE=3D2>Thanks,</FONT>

<BR><FONT SIZE=3D2>Eric</FONT>
</P>

<P><FONT SIZE=3D2>On Wed, 25 Sep 2002, Ricky Scott wrote:</FONT>
</P>

<P><FONT SIZE=3D2>&gt;</FONT>

<BR><FONT SIZE=3D2>&gt; &gt;</FONT>

<BR><FONT SIZE=3D2>&gt; &gt; Read a pinout, find the serial TX, RX &amp; =
GND, solder</FONT>

<BR><FONT SIZE=3D2>&gt; &gt; it to a DB9/DB25</FONT>

<BR><FONT SIZE=3D2>&gt; &gt; cable.&nbsp; Find power.&nbsp; Apply power =
without letting the</FONT>

<BR><FONT SIZE=3D2>&gt; &gt; factory smoke out.</FONT>

<BR><FONT SIZE=3D2>&gt;</FONT>

<BR><FONT SIZE=3D2>&gt;</FONT>

<BR><FONT SIZE=3D2>&gt; Thats Advanced ?, man I wonder what simple would =
be.</FONT>

<BR><FONT SIZE=3D2>&gt; I think I can do that sleeping or at least =
dosing :).</FONT>

<BR><FONT SIZE=3D2>&gt;</FONT>

<BR><FONT SIZE=3D2>&gt;</FONT>

<BR><FONT SIZE=3D2>&gt; Scotty N7HJ</FONT>

<BR><FONT SIZE=3D2>&gt;</FONT>

<BR><FONT SIZE=3D2>&gt; =
__________________________________________________</FONT>

<BR><FONT SIZE=3D2>&gt; Do you Yahoo!?</FONT>

<BR><FONT SIZE=3D2>&gt; New DSL Internet Access from SBC &amp; =
Yahoo!</FONT>

<BR><FONT SIZE=3D2>&gt; <A =
HREF=3D"http://sbc.yahoo.com">http://sbc.yahoo.com</A></FONT>

<BR><FONT SIZE=3D2>&gt; =
_______________________________________________</FONT>

<BR><FONT SIZE=3D2>&gt; Seatcp mailing list</FONT>

<BR><FONT SIZE=3D2>&gt; Seatcp@wetnet.net</FONT>

<BR><FONT SIZE=3D2>&gt; <A =
HREF=3D"http://wetnet.net/mailman/listinfo/seatcp">http://wetnet.net/mail=
man/listinfo/seatcp</A></FONT>

<BR><FONT SIZE=3D2>&gt;</FONT>
</P>

<P><FONT SIZE=3D2>_______________________________________________</FONT>

<BR><FONT SIZE=3D2>Seatcp mailing list</FONT>

<BR><FONT SIZE=3D2>Seatcp@wetnet.net</FONT>

<BR><FONT SIZE=3D2><A =
HREF=3D"http://wetnet.net/mailman/listinfo/seatcp">http://wetnet.net/mail=
man/listinfo/seatcp</A></FONT>
</P>

</BODY>
</HTML>
------=_NextPart_000_0037_01C264A7.7ACA27A0--