Jump to content

NMEA Decoder (position report)

iamtheky

By iamtheky,
in AutoIt Example Scripts

 Share

Recommended Posts

iamtheky Universalist

iamtheky

Posted
Posted (edited)

This function decodes the NMEA position reports (e.g. type 1,2,3) from a ships AIS system and returns a 2D array with labels. 

;~ nmea
#include<array.au3>
#include<file.au3>

$sData = "100NtTwP00JVkTPFit5irww@2>`<"
_ArrayDisplay(_NMEA_Position_Decoder($sData) , $sData)



Func _NMEA_Position_Decoder($sEncString)

$aAsc = StringToASCIIArray($sData)  ; any ASCII over 119 is invalid , ascii 64-87 and 88-95 are not used

for $i = 0 to ubound($aAsc) - 1
    If $aAsc[$i] < 48 Then
        msgbox(0, $aAsc[$i] , $aAsc[$i] & " asc less than 48" & @LF & chrw($aAsc[$i]) & " is not a valid char" )
        exit
    EndIF
    If $aAsc[$i] > 88 And $aAsc[$i] < 95 Then
        msgbox(0, $aAsc[$i] , $aAsc[$i] & " asc in invalid range 88-95")
        exit
    EndIF
    If $aAsc[$i] > 119 Then
        msgbox(0, $aAsc[$i] , $aAsc[$i] & " asc above 119")
        exit
    EndIF
next

;~ _ArrayDisplay($aAsc , 'ASCII values') ;check ASCII conversion
;subtract 48 from each

for $i = 0 to ubound($aAsc) - 1
    $aAsc[$i] = number($aAsc[$i] - 48)
    $aAsc[$i] = $aAsc[$i] > 40 ? $aAsc[$i] - 8 : $aAsc[$i] ; if still over 40 subtract 8
Next

;~ _ArrayDisplay($aAsc, 'armored payload') ;check armored payload

for $i = 0 to UBound($aAsc) - 1

    If $aAsc[$i] = "0" Then $aAsc[$i] = "000000"
    If $aAsc[$i] = "1" Then $aAsc[$i] = "000001"
    If $aAsc[$i] = "2" Then $aAsc[$i] = "000010"
    If $aAsc[$i] = "3" Then $aAsc[$i] = "000011"
    If $aAsc[$i] = "4" Then $aAsc[$i] = "000100"
    If $aAsc[$i] = "5" Then $aAsc[$i] = "000101"
    If $aAsc[$i] = "6" Then $aAsc[$i] = "000110"
    If $aAsc[$i] = "7" Then $aAsc[$i] = "000111"
    If $aAsc[$i] = "8" Then $aAsc[$i] = "001000"
    If $aAsc[$i] = "9" Then $aAsc[$i] = "001001"
    If $aAsc[$i] = "10" Then $aAsc[$i] = "001010"
    If $aAsc[$i] = "11" Then $aAsc[$i] = "001011"
    If $aAsc[$i] = "12" Then $aAsc[$i] = "001100"
    If $aAsc[$i] = "13" Then $aAsc[$i] = "001101"
    If $aAsc[$i] = "14" Then $aAsc[$i] = "001110"
    If $aAsc[$i] = "15" Then $aAsc[$i] = "001111"
    If $aAsc[$i] = "16" Then $aAsc[$i] = "010000"
    If $aAsc[$i] = "17" Then $aAsc[$i] = "010001"
    If $aAsc[$i] = "18" Then $aAsc[$i] = "010010"
    If $aAsc[$i] = "19" Then $aAsc[$i] = "010011"
    If $aAsc[$i] = "20" Then $aAsc[$i] = "010100"
    If $aAsc[$i] = "21" Then $aAsc[$i] = "010101"
    If $aAsc[$i] = "22" Then $aAsc[$i] = "010110"
    If $aAsc[$i] = "23" Then $aAsc[$i] = "010111"
    If $aAsc[$i] = "24" Then $aAsc[$i] = "011000"
    If $aAsc[$i] = "25" Then $aAsc[$i] = "011001"
    If $aAsc[$i] = "26" Then $aAsc[$i] = "011010"
    If $aAsc[$i] = "27" Then $aAsc[$i] = "011011"
    If $aAsc[$i] = "28" Then $aAsc[$i] = "011100"
    If $aAsc[$i] = "29" Then $aAsc[$i] = "011101"
    If $aAsc[$i] = "30" Then $aAsc[$i] = "011110"
    If $aAsc[$i] = "31" Then $aAsc[$i] = "011111"
    If $aAsc[$i] = "32" Then $aAsc[$i] = "100000"
    If $aAsc[$i] = "33" Then $aAsc[$i] = "100001"
    If $aAsc[$i] = "34" Then $aAsc[$i] = "100010"
    If $aAsc[$i] = "35" Then $aAsc[$i] = "100011"
    If $aAsc[$i] = "36" Then $aAsc[$i] = "100100"
    If $aAsc[$i] = "37" Then $aAsc[$i] = "100101"
    If $aAsc[$i] = "38" Then $aAsc[$i] = "100110"
    If $aAsc[$i] = "39" Then $aAsc[$i] = "100111"
    If $aAsc[$i] = "40" Then $aAsc[$i] = "101000"
    If $aAsc[$i] = "41" Then $aAsc[$i] = "101001"
    If $aAsc[$i] = "42" Then $aAsc[$i] = "101010"
    If $aAsc[$i] = "43" Then $aAsc[$i] = "101011"
    If $aAsc[$i] = "44" Then $aAsc[$i] = "101100"
    If $aAsc[$i] = "45" Then $aAsc[$i] = "101101"
    If $aAsc[$i] = "46" Then $aAsc[$i] = "101110"
    If $aAsc[$i] = "47" Then $aAsc[$i] = "101111"
    If $aAsc[$i] = "48" Then $aAsc[$i] = "110000"
    If $aAsc[$i] = "49" Then $aAsc[$i] = "110001"
    If $aAsc[$i] = "50" Then $aAsc[$i] = "110010"
    If $aAsc[$i] = "51" Then $aAsc[$i] = "110011"
    If $aAsc[$i] = "52" Then $aAsc[$i] = "110100"
    If $aAsc[$i] = "53" Then $aAsc[$i] = "110101"
    If $aAsc[$i] = "54" Then $aAsc[$i] = "110110"
    If $aAsc[$i] = "55" Then $aAsc[$i] = "110111"
    If $aAsc[$i] = "56" Then $aAsc[$i] = "111000"
    If $aAsc[$i] = "57" Then $aAsc[$i] = "111001"
    If $aAsc[$i] = "58" Then $aAsc[$i] = "111010"
    If $aAsc[$i] = "59" Then $aAsc[$i] = "111001"
    If $aAsc[$i] = "60" Then $aAsc[$i] = "111100"
    If $aAsc[$i] = "61" Then $aAsc[$i] = "111101"
    If $aAsc[$i] = "62" Then $aAsc[$i] = "111110"
    If $aAsc[$i] = "63" Then $aAsc[$i] = "111111"

next

;~ _ArrayDisplay($aAsc , 'bitstream') ;check bit stream

$sBitStream = _ArrayToString($aAsc , "")

$sMsgType = stringleft($sBitStream , 6)
$sRptIndicator = stringmid($sBitStream , 7 , 2)
$sMMSI = StringMid($sBitStream , 9 , 30)
$sNavStatus   = StringMid($sBitStream , 39 , 4)
$sRateOfTurn = StringMid($sBitStream , 43 , 8)
$sSpeedOverGrnd = StringMid($sBitStream , 51 , 10)
$sPositionAccuracy = StringMid($sBitStream , 61 , 1)
$slongitude = StringMid($sBitStream , 62 , 28)
$slatitude = StringMid($sBitStream , 90 , 27)
$sCourseOverGround = StringMid($sBitStream , 117 , 12)
$sHeading = StringMid($sBitStream , 129 , 9)
$sTimeStamp = StringMid($sBitStream , 138 , 6)
$sManeuverIndicator = StringMid($sBitStream , 144 , 2)
$sSpare = StringMid($sBitStream , 146 , 3) ;unused
$sRAIMflag = StringMid($sBitStream , 149 , 1)
$sRadioStatus = StringMid($sBitStream , 150 , 19) ;ending at 168 (or 28 blocks of 6)

;~ local $aBitStream[1][2] = [["message" , $sMsgType]]

local $aBitStream[16][2] = [["msg_type" , _BinaryToDec($sMsgType)] , ["Repeat Ind" , _BinaryToDec($sRptIndicator)] , ["MMSI" , _BinaryToDec($sMMSI)] , ["Nav Status" , _BinaryToDec($sNavStatus)] , ["Turn Rate" , _BinaryToDec($sRateOfTurn) / 10] , _
["Speed" , _BinaryToDec($sSpeedOverGrnd) / 10] , ["Accuracy" , _BinaryToDec($sPositionAccuracy)] , ["longitude" , $slongitude] , ["latitude" , $slatitude], ["Course" , _BinaryToDec($sCourseOverGround) / 10] , ["Heading" , _BinaryToDec($sHeading)] , ["TimeStamp" , _BinaryToDec($sTimeStamp)] , _
["Maneuver Ind" , _BinaryToDec($sManeuverIndicator)] , ["Spare" , $sSpare] , ["RAIM flag" , _BinaryToDec($sRAIMflag)] , ["Radio Status" , _BinaryToDec($sRadioStatus)]]

Return $aBitStream

EndFunc ;NMEA Position Decoder



;~ ;-------------Binary To Dec-----------------


Func _BinaryToDec($strBin)
Local $Return
Local $lngResult
Local $intIndex

    If StringRegExp($strBin,'[0-1]') then
    $lngResult = 0
    For $intIndex = StringLen($strBin) to 1 step -1
    $strDigit = StringMid($strBin, $intIndex, 1)
    Select
    case $strDigit="0"
    ; do nothing
    case $strDigit="1"
    $lngResult = $lngResult + (2 ^ (StringLen($strBin)-$intIndex))
    case else
    ; invalid binary digit, so the whole thing is invalid
    $lngResult = 0
    $intIndex = 0 ; stop the loop
    EndSelect
    Next

    $Return = $lngResult
        Return $Return
    Else
        MsgBox(0,"Error","Wrong input, try again ...")
        Return
    EndIf
EndFunc

 

Edited by iamtheky 

,-. .--. ________ .-. .-. ,---. ,-. .-. .-. .-.
|(| / /\ \ |\ /| |__ __||| | | || .-' | |/ / \ \_/ )/
(_) / /__\ \ |(\ / | )| | | `-' | | `-. | | / __ \ (_)
| | | __ | (_)\/ | (_) | | .-. | | .-' | | \ |__| ) (
| | | | |)| | \ / | | | | | |)| | `--. | |) \ | |
`-' |_| (_) | |\/| | `-' /( (_)/( __.' |((_)-' /(_|
'-' '-' (__) (__) (_) (__)

Link to comment
Share on other sites
czardas Universalist

czardas

Posted
Posted (edited)

You could simplify and optimize the code - something like this. 

for $i = 0 to UBound($aAsc) - 1

    $aAsc[$i] = StringFormat('%06i', DecToBase($aAsc[$i], 2))

    #cs
    If $aAsc[$i] = "0" Then $aAsc[$i] = "000000"
    If $aAsc[$i] = "1" Then $aAsc[$i] = "000001"
    If $aAsc[$i] = "2" Then $aAsc[$i] = "000010"
    If $aAsc[$i] = "3" Then $aAsc[$i] = "000011"
    If $aAsc[$i] = "4" Then $aAsc[$i] = "000100"
    If $aAsc[$i] = "5" Then $aAsc[$i] = "000101"
    If $aAsc[$i] = "6" Then $aAsc[$i] = "000110"
    If $aAsc[$i] = "7" Then $aAsc[$i] = "000111"
    If $aAsc[$i] = "8" Then $aAsc[$i] = "001000"
    If $aAsc[$i] = "9" Then $aAsc[$i] = "001001"
    If $aAsc[$i] = "10" Then $aAsc[$i] = "001010"
    If $aAsc[$i] = "11" Then $aAsc[$i] = "001011"
    If $aAsc[$i] = "12" Then $aAsc[$i] = "001100"
    If $aAsc[$i] = "13" Then $aAsc[$i] = "001101"
    If $aAsc[$i] = "14" Then $aAsc[$i] = "001110"
    If $aAsc[$i] = "15" Then $aAsc[$i] = "001111"
    If $aAsc[$i] = "16" Then $aAsc[$i] = "010000"
    If $aAsc[$i] = "17" Then $aAsc[$i] = "010001"
    If $aAsc[$i] = "18" Then $aAsc[$i] = "010010"
    If $aAsc[$i] = "19" Then $aAsc[$i] = "010011"
    If $aAsc[$i] = "20" Then $aAsc[$i] = "010100"
    If $aAsc[$i] = "21" Then $aAsc[$i] = "010101"
    If $aAsc[$i] = "22" Then $aAsc[$i] = "010110"
    If $aAsc[$i] = "23" Then $aAsc[$i] = "010111"
    If $aAsc[$i] = "24" Then $aAsc[$i] = "011000"
    If $aAsc[$i] = "25" Then $aAsc[$i] = "011001"
    If $aAsc[$i] = "26" Then $aAsc[$i] = "011010"
    If $aAsc[$i] = "27" Then $aAsc[$i] = "011011"
    If $aAsc[$i] = "28" Then $aAsc[$i] = "011100"
    If $aAsc[$i] = "29" Then $aAsc[$i] = "011101"
    If $aAsc[$i] = "30" Then $aAsc[$i] = "011110"
    If $aAsc[$i] = "31" Then $aAsc[$i] = "011111"
    If $aAsc[$i] = "32" Then $aAsc[$i] = "100000"
    If $aAsc[$i] = "33" Then $aAsc[$i] = "100001"
    If $aAsc[$i] = "34" Then $aAsc[$i] = "100010"
    If $aAsc[$i] = "35" Then $aAsc[$i] = "100011"
    If $aAsc[$i] = "36" Then $aAsc[$i] = "100100"
    If $aAsc[$i] = "37" Then $aAsc[$i] = "100101"
    If $aAsc[$i] = "38" Then $aAsc[$i] = "100110"
    If $aAsc[$i] = "39" Then $aAsc[$i] = "100111"
    If $aAsc[$i] = "40" Then $aAsc[$i] = "101000"
    If $aAsc[$i] = "41" Then $aAsc[$i] = "101001"
    If $aAsc[$i] = "42" Then $aAsc[$i] = "101010"
    If $aAsc[$i] = "43" Then $aAsc[$i] = "101011"
    If $aAsc[$i] = "44" Then $aAsc[$i] = "101100"
    If $aAsc[$i] = "45" Then $aAsc[$i] = "101101"
    If $aAsc[$i] = "46" Then $aAsc[$i] = "101110"
    If $aAsc[$i] = "47" Then $aAsc[$i] = "101111"
    If $aAsc[$i] = "48" Then $aAsc[$i] = "110000"
    If $aAsc[$i] = "49" Then $aAsc[$i] = "110001"
    If $aAsc[$i] = "50" Then $aAsc[$i] = "110010"
    If $aAsc[$i] = "51" Then $aAsc[$i] = "110011"
    If $aAsc[$i] = "52" Then $aAsc[$i] = "110100"
    If $aAsc[$i] = "53" Then $aAsc[$i] = "110101"
    If $aAsc[$i] = "54" Then $aAsc[$i] = "110110"
    If $aAsc[$i] = "55" Then $aAsc[$i] = "110111"
    If $aAsc[$i] = "56" Then $aAsc[$i] = "111000"
    If $aAsc[$i] = "57" Then $aAsc[$i] = "111001"
    If $aAsc[$i] = "58" Then $aAsc[$i] = "111010"
    If $aAsc[$i] = "59" Then $aAsc[$i] = "111001"
    If $aAsc[$i] = "60" Then $aAsc[$i] = "111100"
    If $aAsc[$i] = "61" Then $aAsc[$i] = "111101"
    If $aAsc[$i] = "62" Then $aAsc[$i] = "111110"
    If $aAsc[$i] = "63" Then $aAsc[$i] = "111111"
    #ce
next


Obviously you need to include the missing function: 

Func DecToBase($iInt, $iBase) ; for bases 2 to 9
    Local $iRem, $sRet = ''
    While $iInt > $iBase -1
        $iRem = Mod($iInt, $iBase)
        $sRet = $iRem & $sRet
        $iInt = Int(($iInt - $iRem) /$iBase)
    WEnd
    Return $iInt & $sRet
EndFunc ;==> DecToBase


I always find it interesting to see miscellaneous real world applications of encoded binary information. Thanks for sharing.

Edited by czardas

operator64  ArrayWorkshop

Link to comment
Share on other sites
iamtheky Universalist

iamtheky

Posted
  • Author
Posted

sonofabitch that would have saved many minutes of typing all that out.   

,-. .--. ________ .-. .-. ,---. ,-. .-. .-. .-.
|(| / /\ \ |\ /| |__ __||| | | || .-' | |/ / \ \_/ )/
(_) / /__\ \ |(\ / | )| | | `-' | | `-. | | / __ \ (_)
| | | __ | (_)\/ | (_) | | .-. | | .-' | | \ |__| ) (
| | | | |)| | \ / | | | | | |)| | `--. | |) \ | |
`-' |_| (_) | |\/| | `-' /( (_)/( __.' |((_)-' /(_|
'-' '-' (__) (__) (_) (__)

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...