Ed Anderson wrote:
I just found this description of the Garmin GPS NEMA output sentences.
Ed Anderson
Matthews, NC
RV-6A N494BW
eanderson@carolina.rr.com
------------------------------------------------------------
Simple Text Output Format:
The simple text (ASCII) output contains time, position, and velocity data in
the fixed width fields (not delimited) defined in the following table:
FIELD DESCRIPTION: WIDTH: NOTES:
----------------------- ------- ------------------------
Sentence start 1 Always '@'
----------------------- ------- ------------------------
/Year 2 Last two digits of UTC year
| ----------------------- ------- ------------------------
| Month 2 UTC month, "01".."12"
T | ----------------------- ------- ------------------------
i | Day 2 UTC day of month, "01".."31"
m | ----------------------- ------- ------------------------
e | Hour 2 UTC hour, "00".."23"
| ----------------------- ------- ------------------------
| Minute 2 UTC minute, "00".."59"
| ----------------------- ------- ------------------------
\Second 2 UTC second, "00".."59"
----------------------- ------- ------------------------
/Latitude hemisphere 1 'N' or 'S'
| ----------------------- ------- ------------------------
| Latitude position 7 WGS84 ddmmmmm, with an implied
| decimal after the 4th digit
| ----------------------- ------- ------------------------
| Longitude hemishpere 1 'E' or 'W'
| ----------------------- ------- ------------------------
| Longitude position 8 WGS84 dddmmmmm with an implied
P | decimal after the 5th digit
o | ----------------------- ------- ------------------------
s | Position status 1 'd' if current 2D differential GPS position
i | 'D' if current 3D differential GPS position
t | 'g' if current 2D GPS position
i | 'G' if current 3D GPS position
o | 'S' if simulated position
n | '_' if invalid position
| ----------------------- ------- ------------------------
| Horizontal posn error 3 EPH in meters
| ----------------------- ------- ------------------------
| Altitude sign 1 '+' or '-'
| ----------------------- ------- ------------------------
| Altitude 5 Height above or below mean
\ sea level in meters
----------------------- ------- ------------------------
/East/West velocity 1 'E' or 'W'
| direction
| ----------------------- ------- ------------------------
| East/West velocity 4 Meters per second in tenths,
| magnitude ("1234" = 123.4 m/s)
V | ----------------------- ------- ------------------------
e | North/South velocity 1 'N' or 'S'
l | direction
o | ----------------------- ------- ------------------------
c | North/South velocity 4 Meters per second in tenths,
i | magnitude ("1234" = 123.4 m/s)
t | ----------------------- ------- ------------------------
y | Vertical velocity 1 'U' (up) or 'D' (down)
| direction
| ----------------------- ------- ------------------------
| Vertical velocity 4 Meters per second in hundredths,
\ magnitude ("1234" = 12.34 m/s)
----------------------- ------- ------------------------
Sentence end 2 Carriage return, '0x0D', and
line feed, '0x0A'
----------------------- ------- ------------------------
If a numeric value does not fill its entire field width, the field is padded
with leading '0's (eg. an altitude of 50 meters above MSL will be output as
"+00050").
Any or all of the data in the text sentence (except for the sentence start
and sentence end fields) may be replaced with underscores to indicate
invalid data.
Looks different than the NEMA 0183 protocol but will work fine.
Not quite as easy to handle as NEMA 0183 comma delimited data which
will import directly to a spread sheet. I can write a QB
program to convert it to comma delimited if you wish Ed.
Something like:
OPEN input.dat FOR INPUT AS #1
OPEN output.dat FOR OUTPUT AS #2
ON ERROR GOTO end:
start:
LINE INPUT #1, temp$
file1$=MID$(temp$,xxx,xxx) 'xxx = file pos and len
file2$=MID$(temp$,xxx,xxx)
file3$=MID$(temp$,xxx,xxx)
file4$=MID$(temp$,xxx,xxx)
file5$=MID$(temp$,xxx,xxx)
PRINT #2 file1$,file2$,file3$,file4$,file5$
GOTO start:
end:
CLOSE
SYSTEM
Paul Lamar
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