'GPS Info by doncarlos with atmega128 and PCF8833 display for processing standard NMEA data

$regfile = "m128def.dat"
$crystal = 11059200
$hwstack = 256
$swstack = 256
$framesize = 256
$lib "lcd-pcf8833BR2.lbx"

Config Graphlcd = Color , Controlport = Portc , Cs = 1 , Rs = 0 , Scl = 3 , Sda = 2

'######################## Color definitons ###################################
Const Blue = &B00000011
Const Yellow = &B11111100
Const Red = &B11100000
Const Green = &B00011100
Const Black = &B00000000
Const White = &B11111111
Const Brightgreen = &B00111110
Const Darkgreen = &B00010100
Const Darkred = &B10100000
Const Darkblue = &B00000010
Const Brightblue = &B00011111
Const Orange = &B11111000
'###############################################################################

Config Com1 = 9600 , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0
Config Com2 = 9600 , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0

Config Serialin = Buffered , Size = 250 , Bytematch = 13    ' GPS Buffer

Dim Gps_data_flag As Byte
Dim Strbytes(252) As Byte
Dim Gpsline As String * 251 At Strbytes(1) Overlay          ' NMEA sentence holder
Dim Gpsline_t As String * 251

Dim Strlen As Byte
Dim Index As Byte
Dim Chksum As Byte
Dim Gps_chksum As String * 2
Dim Gps_chksum_b As Byte

Dim Dollar As String * 1
Dim Z As Byte
Dim Gps_adatok(21) As String * 15                                'Array for storing various GPS data

Dim Gpstime_s As String * 10
Dim Gpsdate_s As String * 10
Dim Gpslat_s As String * 10
Dim Gpslon_s As String * 10
Dim Pos_status As String * 1 , Nofix As Bit

Dim Dms_lat As String * 15 , Dms_long As String * 15

Dim We As String * 1 , Ns As String * 1

Dim Pdop As String * 4 , Hdop As String * 4 , Vdop As String * 4 , Magassag As String * 6 , Sebesseg As String * 7

Dim Fix_type(4) As String * 8 , Fix_szam As Byte

Dim Sat_track As String * 2

Dim Timezone As Byte

Dim Perc As String * 2 , Mp As String * 2 , Ora As String * 2 , Ora_b As Byte            'Time values: min, sec, hour
Dim Nap As String * 2 , Honap As String * 2 , Ev As String * 2                                 'Date values: date, month, year
Dim Ido As String * 8 , Datum As String * 8

Dim Sentence_count As Byte , Sentence_num As Byte , Satinview As Byte
Dim Szamlalo As Byte , Szamlalo2 As Byte , Cim As Byte , L As Byte , K As Byte , Cim_temp As Byte , Lineindex As Byte  'some indexing values
Dim Satinfo(64)as String * 3                                                                                 'Array for the PRN display data (PRN, Azimuth, Elevation, SNR)

Dim I As Byte , H As Byte
Dim Index_temp1 As Byte , Index_temp2 As Byte , Dy As Byte , Dx As Byte            'More indexing values

Dim Pr_number As String * 2 , Ele As String * 2 , Azi As String * 3 , Snr As String * 2
Dim Azi_single As Single , Ele_int As Integer

Dim Ticker As Byte

Timezone = 2                                                                                                       'Modify this for setting your timezone

Declare Function Dmtodms(byval Szog_string As String) As String
Declare Sub Skyplot(azimuth As Single , Byval Elevation As Integer , Prn As String * 2 , Byval Ncolor As Byte)

'######################### LCD Init ############################################
Glcdcmd &H21
Glcdcmd &H36
Glcddata &H48                                               '40 = RGB or 48 = BGR
'###############################################################################

Open "Com2:" For Binary As #2
Enable Interrupts

Cls

Print "Serial1 init"
Print #2 , "Serial2 init"

Setfont Color8x8
Lcdat 63 , 30 , "GPS" , Black , White

Cls
Fix_type(1) = "SPS fix"
Fix_type(2) = "DGPS fix"
Fix_type(3) = "PPS fix"
Fix_type(4) = "RTK fix"
Szamlalo = 1
Szamlalo2 = 1

'!!!!!!!!!!!!!!!!!!  For now this is the function selector !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
'!!!!!!!!!!!!!!!!!  uncomment one of the gotos to select  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!! a function, if both commented out the text display will run  !!!!!!!!!!!!!!!!!!

'Goto Sky
'Goto Prn_snr

'!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

'###############################################################################

Lcdat 4 , 2 , "GPS Ido:" , Black , White
Lcdat 14 , 2 , "Koordinatak:" , Black , White
Lcdat 44 , 2 , "Elev:" , Black , White
Lcdat 54 , 2 , "Speed:" , Black , White

Szoveges:
Do
   If Gps_data_flag > 0 Then Gosub Processgps

   If Pos_status = "V" Then
      If Nofix = 1 Then Goto Szoveges
      Nofix = 1
      Lcdat 74 , 2 , "     NO FIX!     " , Black , White
      Lcdat 4 , 66 , "         " , Black , White
      Lcdat 24 , 2 , "                " , Black , White
      Lcdat 34 , 2 , "                " , Black , White
      Lcdat 44 , 56 , "                " , Black , White                        'clearing the display
      Lcdat 54 , 56 , "                " , Black , White                        'this is faster then a cls
      Lcdat 64 , 2 , "                " , Black , White
      Lcdat 94 , 2 , "                " , Black , White
      Lcdat 104 , 2 , "                " , Black , White
      Lcdat 114 , 2 , "                " , Black , White
   Else
      Nofix = 0
      Ora = Mid(gpstime_s , 1 , 2)
      Perc = Mid(gpstime_s , 3 , 2)
      Mp = Mid(gpstime_s , 5 , 2)

      Nap = Mid(gpsdate_s , 1 , 2)
      Honap = Mid(gpsdate_s , 3 , 2)
      Ev = Mid(gpsdate_s , 5 , 2)

      Ora_b = Val(ora) + Timezone
      If Ora_b > 24 Then Ora_b = Ora_b - 24
      Ora = Str(ora_b)

      Ido = Ora + ":" + Perc + ":" + Mp
      Datum = Ev + "." + Honap + "." + Nap

      Dms_lat = Dmtodms(gpslat_s)
      Dms_long = Dmtodms(gpslon_s)

      Lcdat 4 , 66 , Ido , Black , White
      Lcdat 24 , 2 , Ns ; " " ; Dms_lat , Black , White
      Lcdat 34 , 2 , We ; " " ; Dms_long , Black , White
      Lcdat 44 , 56 , Magassag ; "M"
      Lcdat 54 , 56 , Sebesseg ; "Km/h"
      Lcdat 64 , 2 , "Sat trk: " ; Sat_track
      Lcdat 74 , 2 , Fix_type(fix_szam) ; "        "
      Lcdat 94 , 2 , "PDOP: " ; Pdop ; "      "
      Lcdat 104 , 2 , "HDOP: " ; Hdop ; "      "
      Lcdat 114 , 2 , "VDOP: " ; Vdop ; "      "
   End If
Loop
'###############################################################################
Prn_snr:
Cls
Do
   If Gps_data_flag > 0 Then Gosub Processgps

   Lcdat 4 , 2 , "PRN" , Black , White : Lcdat 4 , 34 , "Ele" , Black , White : Lcdat 4 , 70 , "Azi" , Black , White : Lcdat 4 , 102 , "SNR" , Black , White

   For I = 1 To Satinview
      For H = 1 To 4
         Index_temp1 = I - 1
         Index_temp1 = Index_temp1 * 4
         Index_temp2 = H + Index_temp1

         Dy = I - 1
         Dx = H - 1

         Dy = Dy * 8                                        '12
         Dy = Dy + 15

         Dx = Dx * 35
         Dx = Dx + 4

         Setfont Color5x5
         Lcdat Dy , Dx , Satinfo(index_temp2)
         Setfont Color8x8
      Next H
   Next I
Loop
'###############################################################################
Sky:
Cls

Circle(66 , 66) , 60 , Black                                'Drawing the skyplot background
Circle(66 , 66) , 40 , Black                                '            |
Circle(66 , 66) , 20 , Black                                '            |

Line(66 , 0) -(66 , 132) , Black                            '          |
Line(0 , 66) -(132 , 66) , Black                            '          ˇ
Do
   If Gps_data_flag > 0 Then Gosub Processgps
   For I = 1 To Satinview
         Index_temp1 = I - 1
         Index_temp1 = Index_temp1 * 4

         Pr_number = Satinfo(1 + Index_temp1)
         Ele = Satinfo(2 + Index_temp1) : Ele_int = Val(ele)
         Azi = Satinfo(3 + Index_temp1) : Azi_single = Val(azi)

         If Azi_single <> 0 And Ele_int <> 0 And Pr_number <> "" Then
         'Call Skyplot(azi_old , Ele_old , Pr_number , White)
         Call Skyplot(azi_single , Ele_int , Pr_number , Red)
         End If
         'Azi_old = Azi_single : Ele_old = Ele_int
   Next I
Waitms 250
Loop
'###############################################################################
Serial0charmatch:
   Pushall
   Incr Gps_data_flag                                       'Increment the NMEA sentence counter
   Popall
Return

'###############################################################################
Processgps:
Decr Gps_data_flag
'############################################
Do
   Dollar = Inkey()                                         'Start finding
   If Dollar = "" Then Return
Loop Until Dollar = "$"
'############################################

Input Gpsline Noecho

'############################################
Strlen = Len(gpsline)
Chksum = 0
Gps_chksum_b = 0
Strlen = Strlen - 3

For Index = 1 To Strlen
   Chksum = Chksum Xor Strbytes(index)                      'Checksum generation
Next Index

Gps_chksum = Right(gpsline , 2)

Gps_chksum_b = Hexval(gps_chksum)
'#############################################

If Chksum = Gps_chksum_b Then                               'If the checksum matches then we can process the right data
    Gpsline_t = Left(gpsline , Strlen)
    Z = Split(gpsline_t , Gps_adatok(1) , ",")

    Select Case Gps_adatok(1)
      Case "GPRMC"                                          'position and time data
         Pos_status = Gps_adatok(3)

         If Pos_status = "A" Then
            Gpstime_s = Gps_adatok(2)
            Gpsdate_s = Gps_adatok(10)
            Gpslat_s = Gps_adatok(4)
            Gpslon_s = Gps_adatok(6)
            We = Gps_adatok(7)
            Ns = Gps_adatok(5)
         End If

      Case "GPGGA"                                          'fix type, tracked sat number and elevation
         Fix_szam = Val(gps_adatok(7))
         If Fix_szam <> 0 Then Magassag = Gps_adatok(10)
         Sat_track = Gps_adatok(8)

      Case "GPGSA"                                          'DOP values
         Pdop = Gps_adatok(16)
         Hdop = Gps_adatok(17)
         Vdop = Left(gps_adatok(18) , 4)

      Case "GPVTG"                                          'speed
         Sebesseg = Gps_adatok(8)

      Case "GPGSV"
         Satinview = Val(gps_adatok(4))
         Sentence_count = Val(gps_adatok(2))
         Sentence_num = Val(gps_adatok(3))
         If Sentence_num <= Sentence_count Then
            If Sentence_num = Szamlalo Then
            '###################################################################
             For L = 1 To 4                                    'Filling up the satinfo array
               If Szamlalo2 > Satinview Then
                  Szamlalo2 = 1
                  Exit For
               Else
                  For K = 1 To 4
                     Cim_temp = L - 1
                     Cim_temp = Cim_temp * 4
                     Cim = K + Cim_temp
                     Lineindex = K + Cim_temp
                     Lineindex = Lineindex + 4
                     Cim_temp = Sentence_num - 1
                     Cim_temp = Cim_temp * 16
                     Cim = Cim + Cim_temp
                     Satinfo(cim) = Gps_adatok(lineindex)
                  Next K
                  Incr Szamlalo2
               End If
             Next L
             If Szamlalo = Sentence_count Then
               Szamlalo = 1
             Else
               Incr Szamlalo
             End If
            '###################################################################
            End If
         End If

      Case Else
    End Select

End If

Return
'###############################################################################

Function Dmtodms(szog_string As String) As String 'function to convert the nmea degrees and miutes to degrees minutes and seconds
Local Szogmp As Single
Local Fok_s As String * 3 , Szogperc_s As String * 2 , Szogmp_s As String * 5

If Len(szog_string) = 9 Then
   Fok_s = Left(szog_string , 2)
   Szogperc_s = Mid(szog_string , 3 , 2)
   Szogmp_s = Right(szog_string , 5)
   Szogmp_s = "0" + Szogmp_s
   Szogmp = Val(szogmp_s)
   Szogmp = Szogmp * 60
   Szogmp_s = Fusing(szogmp , "#.##")
End If

If Len(szog_string) = 10 Then
   Fok_s = Left(szog_string , 3)
   Szogperc_s = Mid(szog_string , 4 , 2)
   Szogmp_s = Right(szog_string , 5)
   Szogmp_s = "0" + Szogmp_s
   Szogmp = Val(szogmp_s)
   Szogmp = Szogmp * 60
   Szogmp_s = Fusing(szogmp , "#.##")
End If

Dmtodms = Fok_s + Chr(127) + Szogperc_s + Chr(39) + Szogmp_s + Chr(34)      
End Function

Sub Skyplot(azimuth As Single , Elevation As Integer , Prn As String * 2 , Ncolor As Byte)
Local X As Single , Y As Single
Local X1 As Integer , Y1 As Integer
Local X2 As Integer , Y2 As Integer
Local Azimuth_rad As Single
Local Temp As Single , Temp2 As Single

   Temp = Azimuth - 90                                      'Turning the polar coordinate system with 90°
   Azimuth_rad = Deg2rad(temp)

   Temp2 = 90 - Elevation                                   'Inverting the elevation values because for a normal polar coordinate system 90° of elevation would be the furthest and in a skyplot the 90° is the center of the coordinate system
   Temp2 = Temp2 * 0.666667                                 'Scaling down the elevation value because the small screen space


X = Cos(azimuth_rad)
X = X * Temp2                                               'or * Elevation if you have a bigger screen to work with
X = X + 66
X1 = X
X2 = X1 - 4

Y = Sin(azimuth_rad)
Y = Y * Temp2                                               'or * Elevation
Y = Y + 63
Y1 = Y
Y2 = Y1 - 4

Lcdat Y2 , X2 , Chr(132) , Ncolor , White                   'GPS sat icon drawing
Y2 = Y2 + 9 : X2 = X2 - 1                                   'PRN number align
Setfont Color5x5
Lcdat Y2 , X2 , Prn                                         'Prn
Setfont Color8x8
End Sub

Close #2
End
'fonts
$include "color8x8.font"
$include "color5x5.font"
 

Do
   If Gps_data_flag > 0 Then Gosub Processgps

   If Pos_status = "V" Then
      If Nofix = 1 Then Goto Szoveges
      Nofix = 1
      Print "No fix!"
   Else
      Nofix = 0
      Ora = Mid(gpstime_s , 1 , 2)
      Perc = Mid(gpstime_s , 3 , 2)
      Mp = Mid(gpstime_s , 5 , 2)

      Nap = Mid(gpsdate_s , 1 , 2)
      Honap = Mid(gpsdate_s , 3 , 2)
      Ev = Mid(gpsdate_s , 5 , 2)

      Ora_b = Val(ora) + Timezone
      If Ora_b > 24 Then Ora_b = Ora_b - 24
      Ora = Str(ora_b)

      Ido = Ora + ":" + Perc + ":" + Mp
      Datum = Ev + "." + Honap + "." + Nap

      Dms_lat = Dmtodms(gpslat_s)
      Dms_long = Dmtodms(gpslon_s)

      Print Ido
      Print Ns ; " " ; Dms_lat
      Print We ; " " ; Dms_long
      Print Magassag ; "M"
      Print Sebesseg ; "Km/h"
      Print "Sat trk: " ; Sat_track
      Print Fix_type(fix_szam)
      Print "PDOP: " ; Pdop
      Print "HDOP: " ; Hdop
      Print "VDOP: " ; Vdop
   End If
Loop