Newbie GPS_demo.spin question

w4fej · 2014-09-21 07:24

I have the new GPS module from Parallax (28509) and have it working just fine. (neat part by the way) The demo outputs everything to the serial terminal (PST) just fine. The altitude is displayed in meters and I am trying to change it to feet using the "n_altf" method. I cannot for the life of me get that conversion to work and display properly on PST. I'm sure it is something simple that I just can't get my head around. Both files are from the OBEX. Any help would be much appreciated .

Thanks, Mike B.

This code fragment is from GPS_basic.spin

pub s_altm

'' Altitude in meters as z-string, "0.0".."9999.9"

  bytefill(@gpsrslt, 0, RSLT_SIZE)                              ' clear result
  gps_fcopy(@gpsrslt, @ggawork, 9)                              ' get field 9

  return @gpsrslt                                               ' return pointer


pub n_altm | len

'' Altitude in 0.1 meters as decimal value, 0..99999

  s_altm                                                        ' get altitude string
  len := strsize(@gpsrslt)                                      ' get length
  gpsrslt[len-2] := gpsrslt[len-1]                              ' remove decimal point
  gpsrslt[len-1] := 0                                           ' terminate

  return str2dec(@gpsrslt, 6)                                   ' return 0.1 meters 


pub n_altf

'' Altitude in 0.1 feet as decimal value, 0..~30480  
'' -- 1 foot = 0.3048 meters
  n_altm
  return (n_altm * 3_048 / 10_000)                               ' return 0.1 feet

This code fragment is from GPS_demo.spin

   
      moveto(16, 11)
      term.str(gps.n_altf) 
      term.tx(CLREOL)

w4fej · 2014-09-21 09:58

Victory !!

I stumbled onto the answer myself !! I simply changed "term.str(gps.n_altf) to "term.dec(gps.n_altf)" and bang, it displays feet as pretty as you please.....

Mike B.

Chris Savage · 2014-09-22 10:23

s_altm was returning a string whereas n_altf was returning a value. Glad to you see you figured it out.

Courtney Jacobs · 2014-09-22 10:25

Great job; you answered your own question really fast!

Thanks for posting your solution here for everyone to benefit from.

w4fej · 2014-09-22 15:52

@Chris and @Courtney.

Thanks. Sometimes you can't see the forest because of all the stinking trees in the way!! lol

Mike B.

Newbie GPS_demo.spin question

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