Changing GPS co-ordinates into Degrees-Minutes-Seconds

[ScaleRobotics]

I have some ugly code that I could share ... (if you really want it...)

But the basic conversion is *5/300 for minutes and *5/18000 for seconds

For instance 30 minutes *5/300 = .50 degrees


if latitude = 47 deg 32 min 14 sec
47 32' 14"

then we can use:
32 *500/3 = 5333 (really .5333 degrees)

for seconds:
14*50/18 = 38 (really .0038 degrees)

Then add 5333 + 38 = 5371 or .5371 degrees

So, 47.5371 degrees is the answer.

[financecatalyst]

I am confused as well.

[FromTheCockpit]

I have some ugly code that I could share ... (if you really want it...)

But the basic conversion is *5/300 for minutes and *5/18000 for seconds

For instance 30 minutes *5/300 = .50 degrees


if latitude = 47 deg 32 min 14 sec
47 32' 14"

then we can use:
32 *500/3 = 5333 (really .5333 degrees)

for seconds:
14*50/18 = 38 (really .0038 degrees)

Then add 5333 + 38 = 5371 or .5371 degrees

So, 47.5371 degrees is the answer.

I would like to see the code if you dont mind. Currently the coordinates are in a string format. Being new to this field your code will help me to have a starting point and will help me understand and decide the way forward

[ScaleRobotics]

Sorry, let me explain a little more. I will try to explain this better tonight when I get home from work.

The basic conversion is:

Converting Between Decimal Degrees, Degrees, Minutes and Seconds, and Radians
(dd + mm/60 +ss/3600) to Decimal degrees (dd.ff)

dd = whole degrees, mm = minutes, ss = seconds

dd.ff = dd + mm/60 + ss/3600

Example: 30 degrees 15 minutes 22 seconds = 30 + 15/60 + 22/3600 = 30.2561

Decimal degrees (dd.ff) to (dd + mm/60 +ss/3600)

But division by 3600 does not work so well for PICs, so .......

Here are a couple ways of converting 15 minutes:
15minutes/60 = .25 degrees. Unfortunately PicBasicPro will round it off to 0, which we do not like.

So, if we change it to 15minutes*500/3=2500 (you'll notice this is the same as the first equation, only multiplied by 10000). We want whole numbers here, and we will need to add seconds to it in whole numbers too.


Here is one part of my minutes to degrees conversion, but I will try to make this a lot clearer tonight. char_A is the validity character in a gps string called gpsdata.

lathome_min = ((((gpsdata[char_A+9]-48)*10) + (gpsdata[char_A+10]-48))*5)/3    'lathome_min