GPS application - Part I

[Monsterman22]

Hello. I'm a complete noob in the serial and GPS stuff can you please help me getting started?
I run the ComPorts.sbp on my device and this is what I get:
COM3::
COM5:: Serial Cable on COM5:
COM7::
COM8::
COM9::

So in the GPS example I set
Port = 5
in Sub Globals

When I run the app and click mnuConnect:Label1.Text = "Error opening port 5"

What's wrong?? Please help me.
Getting knowlege on these issues is very important to me.

[Monsterman22]

Ooops I tried Port = 3
On clicking mnuConnect : Label1.Text = "Serial port is open"
and in 5 seconds - "No connection" and a msgbox :
"GPS was disconnected.Do you want to reconnect?"

Any help will be much appreciated
Thank you.

[Erel]

Did you connect a GPS to this port?

[Monsterman22]

I just copied the source code.
How am I to connect a GPS to the port?
I have never even used a GPS so please pardon me asking silly questions

[Erel]

Does your device have an internal or external GPS? If it has an internal GPS you could search google to find the port number based on the device model.

[Monsterman22]

My device has external GPS . I have to choose a programm port COM0 to
COM9, GPD1 to GPD9; and a hardware port COM0 to COM9

Running the ComPorts.sbp gives the following result:
COM3::
COM5:: Serial Cable on COM5:
COM7::
COM8::
COM9::



Running GPS4PPC (older version) I get msgbox "Error opening port:5"
If select COM3 I get msgbox "GPS is connected" and in 3 seconds "GPS disconnected"


Edit:

I have querried my device's support service and was told that my RoverPC c6 has no GPS module.

That is wierd as I have on the menu Settings => System => External GPS

[dking]

hey guys,

when i try to compile the file to a Smartphone.exe the Basic4ppc-Desktop-compiler give me the error:"Smartphones do not support listbox control".

what's the issue? must i replace the listbox for something else?


dK

[Zenerdiode]

You appear as an un-registered user. How are you compiling?

Also, because Smartphones do not have touch-screens, some controls that require stylus input can not be used and you get the error above.

[diego]

I'm trying GPSDriver and GPS dll's and I notice that both lat/lon and speed are "moving" without moving, e.g. the speed fluctuates (2km/h, 4km/h...), so it's impossible to make a reliable distance calculation using this sample code:

Sub getDistanceKM(lat1, long1, lat2, long2)

    DEGREES_TO_RADIANS = (cPI / 180.0)
    EARTH_RADIUS = 6371.0
    
    rlat1 = DEGREES_TO_RADIANS * lat1
    rlong1 = DEGREES_TO_RADIANS * long1
    rlat2 = DEGREES_TO_RADIANS * lat2
    rlong2 = DEGREES_TO_RADIANS * long2
    
    '    There is no real reason To break this lot into 
    '    4 statements but I just feel it's a little more 
    '    readable.
    p1 = Cos(rlat1) * Cos(rlong1) * Cos(rlat2) * Cos(rlong2)
    p2 = Cos(rlat1) * Sin(rlong1) * Cos(rlat2) * Sin(rlong2)
    p3 = Sin(rlat1) * Sin(rlat2)

    ret = p1 + p2 + p3
    If ret = 1 Then Return 0
    
    ret = ACos(ret)
    ret = ret * EARTH_RADIUS
    
    Return ret
    
End Sub

[mjcoon]

Originally Posted by diego

I notice that both lat/lon and speed are "moving" without moving, e.g. the speed fluctuates (2km/h, 4km/h...), so it's impossible to make a reliable distance calculation ...

That's probably the inherent inaccuracy of a simple GPS receiver. Which is why, in http://www.basic4ppc.com/forum/open-...html#post36567 I included an averaging function.

Unfortunately I made the mistake of averaging the direction of travel too. When that alternates between 359 and 001 degrees the average comes out at 180, which is south rather than north! I haven't got a solution for that yet... (Klaus?)

Mike.