For Jon: GPS article in Nuts & Volts (RS-232)
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Hi Jon, many thanks on the pointer for LCD interfacing.
I enjoyed reading your excellent "Stamping down the road" article in
Nuts & Volts issue 103.
I'm a newbie obviously to Stamp, and am itching to try it out (last
time I did microcontrollers was in college with a DEC PDP-8 and PDP-
11 doing DSP FFT routines, it was a ton of fun back then).
I have the RadioShack Basic Stamp special (what's a microcontroller
kit that comes with the Homework board (BS2-IC soldered on PCB).
I've tried interfacing to my Garmin Rino GPS unit and doing SERIN on
pin 0.
However, I'm seeing garbage when I DEBUG it out (i.e. the characters
read is mostly ASCII 255 (I did a DEBUG DEC letter, CR).
I'm thinking my wiring to the GPS unit is wrong:
pin 0 -> 22 k ohm resistor -> male RS-232 jack pin 2 -> GPS unit
(GPS unit has the female RS-232 plug)
pin 5 -> male RS232 jack pin 5
If I unplug the GPS unit from the RS-232 jack the Stamp is listening
to, I still get garbage displayed. Leads me to think that it's
picking stray signals.
How did you connect and debug your article on the breadboard?
Many Thanks ! Caesar.
I enjoyed reading your excellent "Stamping down the road" article in
Nuts & Volts issue 103.
I'm a newbie obviously to Stamp, and am itching to try it out (last
time I did microcontrollers was in college with a DEC PDP-8 and PDP-
11 doing DSP FFT routines, it was a ton of fun back then).
I have the RadioShack Basic Stamp special (what's a microcontroller
kit that comes with the Homework board (BS2-IC soldered on PCB).
I've tried interfacing to my Garmin Rino GPS unit and doing SERIN on
pin 0.
However, I'm seeing garbage when I DEBUG it out (i.e. the characters
read is mostly ASCII 255 (I did a DEBUG DEC letter, CR).
I'm thinking my wiring to the GPS unit is wrong:
pin 0 -> 22 k ohm resistor -> male RS-232 jack pin 2 -> GPS unit
(GPS unit has the female RS-232 plug)
pin 5 -> male RS232 jack pin 5
If I unplug the GPS unit from the RS-232 jack the Stamp is listening
to, I still get garbage displayed. Leads me to think that it's
picking stray signals.
How did you connect and debug your article on the breadboard?
Many Thanks ! Caesar.
Comments
I enjoyed reading your excellent "Stamping down the road" article in
Nuts & Volts issue 103.
I'm a newbie obviously to Stamp, and am itching to try it out (last
time I did microcontrollers was in college with a DEC PDP-8 and PDP-
11 doing DSP FFT routines, it was a ton of fun back then).
I have the RadioShack Basic Stamp special (what's a microcontroller
kit that comes with the Homework board (BS2-IC soldered on PCB).
I've tried interfacing to my Garmin Rino GPS unit and doing SERIN on
pin 0.
However, I'm seeing garbage when I DEBUG it out (i.e. the characters
read is mostly ASCII 255 (I did a DEBUG DEC letter, CR).
I'm thinking my wiring to the GPS unit is wrong:
pin 0 -> 22 k ohm resistor -> male RS-232 jack pin 2 -> GPS unit
(GPS unit has the female RS-232 plug)
pin 5 -> male RS232 jack pin 5
If I unplug the GPS unit from the RS-232 jack the Stamp is listening
to, I still get garbage displayed. Leads me to think that it's
picking stray signals.
How did you connect and debug your article on the breadboard?
Many Thanks ! Caesar.
can connect it directly to the Stamp without problems -- I always have.
I have used the unpowered Garmin interface cable (expensive!) and have
wired my own from parts found on the Internet.
I'm not sure what you're trying to do, but it seems you're trying to
intercept the data then send it straight to the DEBUG window. No can do
-- especially with the BS2. If you use a BS2p or BS2pe (as I do with a
all of my GPS projects), you can buffer the stream into Scratchpad and
then display it.
With anything other than the BS2p/pe, you have to play the WAIT and SKIP
game to get GPS data -- a pain. Make sure that you set your GPS for
NMEA OUT at 4800 baud. The speed of the BS2 makes it really tough to do
much with GPS without buffering a small segment, then pulling the data
out. I just wrote a little demo and ran it on a HomeWork Board that
should get you going. My Garmin is connect directly to P0 (serial out
from GPS) and Vss (ground). It's not terribly exciting (captures and
displays current local time), but it does work.
I will post it to the files section.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: caesarsamsi [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=LdlLGrmSJzyjHBQER73Z2b4FgKX8EztQT35Yuao8xu0L1sNuxsYodPM8NrjASBmG60k9PgcXTAmoBPW3yw]cmsamsi@h...[/url
Sent: Monday, February 02, 2004 12:26 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] For Jon: GPS article in Nuts & Volts (RS-232)
Hi Jon, many thanks on the pointer for LCD interfacing.
I enjoyed reading your excellent "Stamping down the road" article in
Nuts & Volts issue 103.
I'm a newbie obviously to Stamp, and am itching to try it out (last
time I did microcontrollers was in college with a DEC PDP-8 and PDP- 11
doing DSP FFT routines, it was a ton of fun back then).
I have the RadioShack Basic Stamp special (what's a microcontroller
kit that comes with the Homework board (BS2-IC soldered on PCB).
I've tried interfacing to my Garmin Rino GPS unit and doing SERIN on
pin 0.
However, I'm seeing garbage when I DEBUG it out (i.e. the characters
read is mostly ASCII 255 (I did a DEBUG DEC letter, CR).
I'm thinking my wiring to the GPS unit is wrong:
pin 0 -> 22 k ohm resistor -> male RS-232 jack pin 2 -> GPS unit
(GPS unit has the female RS-232 plug)
pin 5 -> male RS232 jack pin 5
If I unplug the GPS unit from the RS-232 jack the Stamp is listening
to, I still get garbage displayed. Leads me to think that it's
picking stray signals.
How did you connect and debug your article on the breadboard?
Many Thanks ! Caesar.
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I was taking this slowly and trying out one piece of the circuit at
a time. The finished project is a location logger, and optionally
(if I get that far as I need to get around the small RAM size) a
vehicle tracker by connecting it to a mobile phone data port.
I'm having so much fun I think I'll just order the stampworks kit :-)
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> The data out of the Garmin is TTL level (I checked with a scope)
so you
> can connect it directly to the Stamp without problems -- I always
have.
> I have used the unpowered Garmin interface cable (expensive!) and
have
> wired my own from parts found on the Internet.
>
> I'm not sure what you're trying to do, but it seems you're trying
to
> intercept the data then send it straight to the DEBUG window. No
can do
> -- especially with the BS2. If you use a BS2p or BS2pe (as I do
with a
> all of my GPS projects), you can buffer the stream into Scratchpad
and
> then display it.
>
> With anything other than the BS2p/pe, you have to play the WAIT
and SKIP
> game to get GPS data -- a pain. Make sure that you set your GPS
for
> NMEA OUT at 4800 baud. The speed of the BS2 makes it really tough
to do
> much with GPS without buffering a small segment, then pulling the
data
> out. I just wrote a little demo and ran it on a HomeWork Board
that
> should get you going. My Garmin is connect directly to P0 (serial
out
> from GPS) and Vss (ground). It's not terribly exciting (captures
and
> displays current local time), but it does work.
>
> I will post it to the files section.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office