Adafruit Ultimate GPS Parsing Example

For other supported Arduino products from Adafruit: Shields, accessories, etc.

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
jj7
 
Posts: 5
Joined: Thu Jan 17, 2013 1:48 pm

Adafruit Ultimate GPS Parsing Example

Post by jj7 »

Hey everybody,
I am using the Adafruit Ultimate GPS with an Arduino Atmega 2560 and I am having trouble reading the parsed data output (The parsing.ino example). More specifically, the location is being formatted as XXXX.XXXX with an appended N, S, E or W. I know latitude and longitude should be values between -90 and 90 and -180 and 180 respectively.

I ran the LOCUS example and used the online parser at http://ladyada.net/products/ultimategps/ and it gave me the output I expected (when plotted in google maps). I noticed that the coordinates obtained from the online parser are similar to the coordinates in the form of XXXX.XXXX except that the decimal is shifted to the right by two. Coincidence? I am not sure so any guidance would be very much appreciated.

For example:
The data from the online parser gave me -76.74775847765905,39.260605723930084 (Longitude, Latitude)
The real time data parser gave me Location: 3915.6442N, 7644.8696W (Latitude, Longitude)

The North Latitude and East Longitude correspond to a positive number and South Latitude and West Longitude correspond to a negative number.
So the numbers are very similar if the second set both have their decimal points shifted to the left two digits but are very different when plotted on a map.

Thanks in advance,
Jeff

User avatar
arctic_eddie
 
Posts: 233
Joined: Tue Feb 28, 2012 6:01 pm

Re: Adafruit Ultimate GPS Parsing Example

Post by arctic_eddie »

The online parser is in degrees and fractions of a degree. The real time parser is in degrees, minutes and fractions thereof after shifting the decimal point two positions to the left. This is the NMEA sentence. See table 2 on page 19 for data format details.

http://www.adafruit.com/datasheets/Glob ... et-V0A.pdf

jj7
 
Posts: 5
Joined: Thu Jan 17, 2013 1:48 pm

Re: Adafruit Ultimate GPS Parsing Example

Post by jj7 »

Hey,
Thanks for the quick response, that makes sense and I have finally figured it out. Thanks again for your help.
Cheers!
-Jeff

User avatar
arctic_eddie
 
Posts: 233
Joined: Tue Feb 28, 2012 6:01 pm

Re: Adafruit Ultimate GPS Parsing Example

Post by arctic_eddie »

No problem, glad to help.

Locked
Please be positive and constructive with your questions and comments.

Return to “Other Arduino products from Adafruit”