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Science Forum Index » Geology - Satellite Navigation Forum » Garmin Vista 'RS232' output NMEA...
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| da... |
 Posted: Wed Aug 13, 2008 5:54 am |
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Hello, Anyone know if my Garmin Vista's (old one) RS232 if 0-5 Volt or
proper RS232 -12v +12v, why I need to know is can I connect it directly to
a micro controller (TTL 0-5 volt) or do I need a max232 chip to convert it. |
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| Dan Anderson... |
| Posted: Wed Aug 13, 2008 12:27 pm |
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da wrote:
Quote: Hello, Anyone know if my Garmin Vista's (old one) RS232 if 0-5 Volt or
proper RS232 -12v +12v, why I need to know is can I connect it directly to
a micro controller (TTL 0-5 volt) or do I need a max232 chip to convert it.
In general, Garmin receivers are not proper RS232. It's been
more than a few years since I looked at an eTrex Venture's
output, but I believe it was 0 to about 2V. The high was
a bit below battery voltage (I use NiMH).
--
Dan
Personal: www.gpsmap.net
Business:
Western Maps LLC
www.westernmaps.us |
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| da... |
| Posted: Wed Aug 13, 2008 1:14 pm |
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"Dan Anderson" <noEMail at (no spam) noServer.net> wrote in message
news:OLKdnTJeQqIPlj7VnZ2dnUVZ_h-dnZ2d at (no spam) pghconnect.com...
Quote: da wrote:
Hello, Anyone know if my Garmin Vista's (old one) RS232 if 0-5 Volt or
proper RS232 -12v +12v, why I need to know is can I connect it directly
to a micro controller (TTL 0-5 volt) or do I need a max232 chip to
convert it.
In general, Garmin receivers are not proper RS232. It's been
more than a few years since I looked at an eTrex Venture's
output, but I believe it was 0 to about 2V. The high was
a bit below battery voltage (I use NiMH).
--
Dan
Personal: www.gpsmap.net
Business:
Western Maps LLC
www.westernmaps.us
Hi Dan, Thanks for that I guessed as much - I could have looked on my
oscilloscope but that is in a box, 'somewhere'.
Dave. |
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| Peter Bennett... |
| Posted: Thu Aug 14, 2008 4:21 pm |
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On Wed, 13 Aug 2008 11:54:26 +0100, "da" < at (no spam) .com> wrote:
Quote: Hello, Anyone know if my Garmin Vista's (old one) RS232 if 0-5 Volt or
proper RS232 -12v +12v, why I need to know is can I connect it directly to
a micro controller (TTL 0-5 volt) or do I need a max232 chip to convert it.
My Garmins all have been 0-5volt, but RS-232 "polarity" , so that they
will work with a normal PC serial port. You will need an inverter on
your microcontroller serial input to get the signal the"right way up"
for the microcontroller's serial input.
--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca |
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| da... |
| Posted: Fri Aug 15, 2008 4:13 am |
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"Peter Bennett" <peterbb at (no spam) somewhere.invalid> wrote in message
news:5489a4tu0dh5jq57r0c61ndqhs4ock5gbv at (no spam) news.supernews.com...
Quote: On Wed, 13 Aug 2008 11:54:26 +0100, "da" < at (no spam) .com> wrote:
Hello, Anyone know if my Garmin Vista's (old one) RS232 if 0-5 Volt or
proper RS232 -12v +12v, why I need to know is can I connect it directly
to
a micro controller (TTL 0-5 volt) or do I need a max232 chip to convert
it.
My Garmins all have been 0-5volt, but RS-232 "polarity" , so that they
will work with a normal PC serial port. You will need an inverter on
your microcontroller serial input to get the signal the"right way up"
for the microcontroller's serial input.
--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
Ah-ha, many thanks for that, so logic 1 would be '0 volt' and logic 0 5
volt. So on the 9pin DIN lead would be the same, or does the Garmin lead
change anything ?
Dave - G6ZKC |
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| peter... |
| Posted: Fri Aug 15, 2008 1:49 pm |
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Guest
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On Aug 15, 1:13 pm, Dan Anderson <noEM... at (no spam) noServer.net> wrote:
Quote: Peter Bennett wrote:
My Garmins all have been 0-5volt, but RS-232 "polarity" , so that they
will work with a normal PC serial port. You will need an inverter on
your microcontroller serial input to get the signal the"right way up"
for the microcontroller's serial input.
I checked a GPS 76 and got -5 to 5V. On a GPSmap 76S, I got 0 - 5V
and on GPSmap 76C[S]x, I got about -6 to 6V. A 12XL was 0 - 5V.
The ~2V I mentioned in my other post was probably from a PDA when
I was trying to get it to work with the receivers.
The GPS 76 was a repair replacement and might have newer hardware
than the 76S.
Interesting that there's so much variation. My eMap puts out -6v/+6v
pulses. It came out before any of the 76 models but after the 12XL. |
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| Dan Anderson... |
| Posted: Fri Aug 15, 2008 3:13 pm |
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Guest
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Peter Bennett wrote:
Quote: My Garmins all have been 0-5volt, but RS-232 "polarity" , so that they
will work with a normal PC serial port. You will need an inverter on
your microcontroller serial input to get the signal the"right way up"
for the microcontroller's serial input.
I checked a GPS 76 and got -5 to 5V. On a GPSmap 76S, I got 0 - 5V
and on GPSmap 76C[S]x, I got about -6 to 6V. A 12XL was 0 - 5V.
The ~2V I mentioned in my other post was probably from a PDA when
I was trying to get it to work with the receivers.
The GPS 76 was a repair replacement and might have newer hardware
than the 76S.
--
Dan
Personal: www.gpsmap.net
Business:
Western Maps LLC
www.westernmaps.us |
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