How to read Data from my GPS module?

[AlainB]

As I said before, my app mimic the GOTO function that you will have in almost if not all the handheld GPS. It is very usefull in many differents situations. It has nothing to do with turn by turn navigation.

There are many apps available for Android that do the same thing and they are doing it much more nicely than mine I am sure. But these apps, like my handheld GPS are loaded with lots of almost useless screen that, I for one, never use. You should see the number of time I have to press buttons before finally being ready to go to the destination with any of my handheld GPS.

On my app, you will click on the Destination Label (The second label) and will appear the list of the already saved POI (points of interest). Chose one and you will be ready to go. The only other thing that you will be able to do is to save the actual location as a new POI. That's all. These 2 functions are not made yet.

Mainly, what I would be extremely interested in is comments on the code that I post here. How maybe it could be improved, be made more efficient.

Edited September 16, 2012 by AlainB

[Cyber]

Maybe this could help:

 

#include <WinAPI.au3>
$RESULT = _WinAPI_CreateFile(".COM3", 2, 2)
If $RESULT = 0 then
msgbox(16, "", "Port not available, please plug in your device")
else
$tBuffer = DllStructCreate("byte[6]")
_WinAPI_ReadFile($RESULT, DllStructGetPtr($tBuffer), 6, $nBytes)
_WinAPI_CloseHandle($RESULT)
$sText = BinaryToString(DllStructGetData($tBuffer, 1))
msgbox(64, "Reading", "This is the output of 6 bytes from COM3: " & $sText)
EndIf

 

Fantastic!

this code is good for read

but for write?

thanks

[Jos]

Write to what ? The gps module likely will be read only.

Jos

[Cyber]

Write to what ? The gps module likely will be read only.

Jos

Yes, sorry

I use it for read of relay state

Can i send write on digital input?

General input

Not for gps

Edited January 11, 2015 by Cyber

[Jos]

Can i send write on digital input?

General input

 

Sorry, but this still doesn't make much sense to me:"Write to digital input?"

Try to be a little bit more explicit what you exactly want to accomplish.

Jos

[Cyber]

Sorry, but this still doesn't make much sense to me:"Write to digital input?"

Try to be a little bit more explicit what you exactly want to accomplish.

Jos

 

ok il try

 

i use this code for read input from pin 3 of my arduino:

#include <WinAPI.au3>
$RESULT = _WinAPI_CreateFile("\\.\COM3", 2, 2)
$nBytes=1
$nBytesw=0
$pin = 3
If $RESULT = 0 then
msgbox(16, "", "Port not available, please plug in your device")
else
$tBuffer = DllStructCreate("byte[6]")
_WinAPI_ReadFile($RESULT, DllStructGetPtr($tBuffer),$pin , $nBytes)
_WinAPI_CloseHandle($RESULT)
$sText = BinaryToString(DllStructGetData($tBuffer, 1))
msgbox(64, "Reading", "This is the output of 6 bytes from COM3: " & $sText)

EndIf

I take the code from this post....

and now, i want to send input 0 or 1 to digital pin 3

is it possibile?

Edited January 12, 2015 by Cyber

[Cyber]

please help me

[littlebigman]

On 9/14/2012 at 9:42 PM, AlainB said:

Here is the code that I use to calculate the distance between 2 coordinates and also the bearing. It is quite accurate, within 50 meters on a 5000 or so Km distance, from Montreal to Anchorage.

For those who just need to compute the distance between two locations in lat+lon, and in meters instead of km:

#include <Math.au3>

Func _atan2($y, $x)
    Return (2 * ATan($y / ($x + Sqrt($x * $x + $y * $y))))
EndFunc

Func _DistanceInMeters($Lat1,$Lon1,$Lat2,$Lon2)
    Local $Distance

    ;Calculating the distance
    Local $R = 6378.1 ;Earth radius in Km (Possibly the value used by Google to calculate distances)
    Local $dLat = _Radian($lat2-$lat1)
    Local $dLon = _Radian($lon2-$lon1)
    Local $lat11 = _Radian($lat1)
    Local $lat22 = _Radian($lat2)
    Local $a = sin($dLat/2) * sin($dLat/2) + sin($dLon/2) * sin($dLon/2) * cos($lat11) * cos($lat22)
    Local $c = 2 * _atan2(sqrt($a), sqrt(1-$a));
    $Distance = $R * $c
    $Distance = Round($Distance,2) * 1000 ;Round to two decimal places, and convert to meters
    Return $Distance
EndFunc

$distance =_DistanceInMeters($REF_LAT, $REF_LON, $GpsLatitude_Decimal, $GpsLongitude_Decimal)
ConsoleWrite(StringFormat("CurrLat %s CurrLon %s Distance %s"  & @CRLF,$GpsLatitude_Decimal, $GpsLongitude_Decimal,$distance))

 

[RTFC]

Three observations:

1. you're reviving a long-dead thread.
2. Other than the final conversion from km to meters (actually 10m, given you round to two decimals instead of three, why?), the distance calculation is identical to the earlier-posted one.
3. Suggesting accuracy to the meter (given your function's name) is misleading, not only because of the 10m fudge factor, but more importantly, because the calculation itself is inaccurate, in assuming a spherical Earth (its radius is ca. 21 kilometers less at the poles); GPS instead uses a reference ellipsoid such as WGS-84. If accuracy to the meter is required, you'll need a specific ellipsoid for a given part of the globe (for example, an Airy ellipsoid for mainland Britain); needless to say, such a computation is more involved. Finally, in the context of GPS usage, if you hold several commercial GPS devices next to one another, they often don't agree very well, so deriving a distance in meters from a (commerical-device's) GPS-produced output won't be accurate anyway (military-grade GPS devices are another story though...).

Edited June 8, 2023 by RTFC

[littlebigman]

I don't understand why it's such a problem adding to a thread that dealt with the same problem, or close enough to not justify creating a new one, but I can live with that.