SparkFun Forums

[RancidWannaRiot]

Hi,

so.. i'm comparing my EM406 output with google earth.. i'm getting between 5 and 7 locks...

this thing is off by quit a bit though.. it's unacceptable for my project..

i'm just curious.. what kind of accuracy are you guys getting?

the datasheet say's 10m of accuracy.. i am getting no where near that...

is it possible that google earth is off?

[RancidWannaRiot]

What kind of accuracy is everyone else getting? i determined it's about a mile off for me.. with 5-7 locks... jesus this sucks.. this is no good for what i'm trying to do.. I can't have more than say 100- 150 meters off..

bleh...

[NleahciM]

Haven't checked for a while - but within buildings I was getting about 5-10 satellites and it was pointing me about 30m or so from where I actually was.

[RancidWannaRiot]

hummmm...

yea this thing is pointing me like a mile or more off.. i'm gonna call sparkfun. i'm starting to think this is defective or something.. i've tried it indoors and outdoors.. i get the same reading.. 5 - 8 locks..

and i've tried it indoors and outdoors in two locations.. and i get get about a mile off in both places..

(the first place is my apartment.. and the second place is my parents house about 300 miles away)

are there any other settings i should enable or something??

i basically just plugged it in.. and started reading stuff.. should i do anything else... other than that?

[seulater]

the EM-406 is one of the better GPS units there are.
i ahve used these with great results. however i am not using it for map location information. if your doing work with GPS for location information it might be a good idea to pick up a Garmin GPS unit from the local store to compare the data with.

[RancidWannaRiot]

the EM-406 is one of the better GPS units there are.
i ahve used these with great results. however i am not using it for map location information. if your doing work with GPS for location information it might be a good idea to pick up a Garmin GPS unit from the local store to compare the data with.

isn't the point of any GPS to track location?

anyway, 1 mile error when the datasheet say's 10 meters of error is not acceptable.. i mean 50 meters of error would even be okay for what i'm doing.. and other poeple have stated they have had about 30 meters of error.. which would be okay in my case...

also.. the EM406 would be way easier to interface to a micro controller.. i don't want to hack a garmin.. and pay a crap load of money on top of that..



bleh.. well i sent off an e-mail to sparkfun with some questions, i triewd calling but i expected they would be closed on sunday..which it appears they are.. and i'm considering just returning it.. if i can..and come up with a project that doesn't involve GPS...

I just don't see why the error is so large when the datasheet indicates that it should be so small... but then again.. they could have written it in a misleading way.. like it's only 10m accurate 1% of the time it's running.. or something...

bleh.. it looks like it might be time to head back to the drawing board and come up with something different...

another thing is.. when i first fired it up.. it took over 3 hours to get it's first locks.. is that normal??

bleh can't wait to talk to someone from spark fun tomrrow.. see waht they think..

[NleahciM]

I wonder if you're doing something funny with the GPS data? Try using a program that connects directly to the GPS. Something like this: http://mehere.glenmurphy.com/

[RancidWannaRiot]

I wonder if you're doing something funny with the GPS data? Try using a program that connects directly to the GPS. Something like this: http://mehere.glenmurphy.com/

it turns out i was doing something funny with the GPS data...

i'm a moron..

okay.. so.. i got it.. and it is working pretty good.. here's what i did wrong..

the datasheet say's the long and lat data is putout in ddmm.mmmm

I was reading it as ddmmss.ss

lol

so i guess my last question is..

how do i enable WAAS??? if i can make it more accurate i would like to..

now when i read it.. it's only off by like 20 - 100 ft which is acceptable for what i'm trying to do..

basically it was human error.. i'm such a moron.. lol


thanks for the replies though..