Thread: GPS Speedometer?

SEARCH!!! There's a lot of topics on this!

alright just searched through over 10 pages of search results and didn't find what i was looking for. Mind telling me what the program is called?

don't know of any standalones off hand, but I know that Street Atlas 2004 gives you your speed.

so that means I'm sure you can get one.. if not, get street atlas

you really should get that thing fixed.. or actually not. then you get 1 get-out-of-speeding-ticket free card.

I asked the same question a while back regardi ng the same issue.
I emailed him and here was his reponse.

The speed info is sent in the nmea stream you get from your GPS reciever.
Its pretty much just one type of stream that gives you that info.

It will look something like this

$GPRMC,224043.051,A,5152.435,N,00159.5732,W,000.0, 238.8,190603,003.7,W*6C

so the 7th or 8th value is the speed in knotts, which in this example is
000.0.

So the conversion to change knotts to mph is

000.0 * 1.151


From what I've seen with just dumping the nmea stream you only get 3 types
of strings coming in. At least from my reciever.

$GPRMC
$GPGSV
$GPGGA

There are a few websites out there that'll tell you everything about the
streams you'd ever want to know. So pretty much the reciever does all the
work, you just have to grab the right string and get the value and do the
math.

Mike

I have a speedometer running on my test software, uses $GPRMC data.

Give me some time, I will cut out the code and build a standalone Speedo.

If you have a graphic if the Speedo dial, and resolution you want to use.

PM me the graphic.

I can only try!!

Ok, let me get this straight, your speedometer which works off the basic principal of counting how fast your wheels are spinning isn't working so instead of fixing it your gonna rely on a multi billion dollar system of satellites and calculations the must be performed thousands of time a second just to get a speed approximation that isn't anywhere near as accurate... this sound's like a government project to me.

Speedometers lie!!@ GPS doesnt! (Well it does, but its because of the government!)

While GPS doesn't update anywhere near as fast as your speedometer, it's a far more accurate indicator of your speed then the speedo on your dash. Speedometers have inaccuracies introduced by everything from tire wear to deliberate overreporting to reduce car accidents.

the only reason I think hes doing it, is because he CAN.. lol and thats without doubt the best reason anyone can have. :-)

Steve