$regfile = "attiny85.dat"
$crystal = 8000000

Dim Colour(3) As Single
Dim Black(3) As Single
Dim White(3) As Single
Dim Eblack(3) As Eram Single
Dim Ewhite(3) As Eram Single
Dim Colourout(3) As Byte
Dim Sensinput As Byte
Dim Sensoutput As Byte
Dim Samples As Byte
Dim Modus As Byte
Dim Rest As Byte                                            '10ms/LSB
Dim Acclim As Byte                                          '1ms/LSB
Dim Settings(6) As Byte

Dim I As Byte
Dim J As Byte

Config Portb.0 = Output
Config Portb.1 = Output
Config Portb.2 = Output
Config Portb.4 = Input

Config Adc = Single , Prescaler = Auto
Start Adc

Declare Function Getreading(byval Times As Byte) As Single
Declare Sub Setbalance
Declare Sub Getcolour
Declare Sub Outputcolour

Modus = 0
Portb.0 = 1
Portb.1 = 1
Portb.2 = 1

Do

Select Case Modus

   Case 0:
      Serin Settings(1) , 6 , B , 3 , 9600 , 0 , 8 , 1
      If Settings(6) = Crc8(settings(1) , 5) Then
            Modus = Settings(1)
            Samples = Settings(2) D
            Acclim = Settings(3)
            Rest = Settings(4) * 10
            Sensoutput = &HAA
      Else
            Sensoutput = &HAB
      End If
      Serout Sensoutput , 1 , B , 5 , 9600 , 0 , 8 , 1
      If Sensoutput = &HAA And Settings(5) = 1 Then
            Call Setbalance
      End If

   Case 1:
      Call Getcolour
      Call Outputcolour
      Wait Rest

   Case 2:
      Serin Sensinput , 1 , B , 3 , 9600 , 0 , 8 , 1
      If Sensinput = &HBB Then
      Call Getcolour
      Call Outputcolour
      End If
End Select

Loop

End


Function Getreading(byval Times As Byte) As Single
      Local Tally As Single
      Tally = 0
      Local Reading As Integer
      Reading = 0
      For J = 1 To Times
         Reading = Getadc(2)
         Tally = Tally + Reading
         Waitms 10
      Next
      Getreading = Tally / Times
End Function

Sub Getcolour
      Local Greydiff As Single
      For I = 0 To 2
        Toggle Portb.i
        Waitms Acclim
        Colour(i + 1) = Getreading(samples)
        Toggle Portb.i
        White(i + 1) = Ewhite(i + 1)
        Black(i + 1) = Eblack(i + 1)
        Greydiff = White(i + 1) - Black(i + 1)
        Colour(i + 1) = Colour(i + 1) - Black(i + 1)
        Colour(i + 1) = Colour(i + 1) / Greydiff
        Colour(i + 1) = Colour(i + 1) * 255
        Colour(i + 1) = Round(colour(i + 1))
        If Colour(i + 1) < 0 Then Colour(i + 1) = 0
        If Colour(i + 1) > 255 Then Colour(i + 1) = 255
        Colourout(i + 1) = Colour(i + 1)
        Waitms Acclim
      Next
End Sub

Sub Outputcolour
      For I = 1 To 3
         Serout Colourout(i) , 1 , B , 5 , 9600 , 0 , 8 , 1
      Next
End Sub

Sub Setbalance
     Sensoutput = &HAC
     Serout Sensoutput , 1 , B , 5 , 9600 , 0 , 8 , 1
     Wait 5
     For I = 0 To 2
         Toggle Portb.i
         Waitms Acclim
         White(i + 1) = Getreading(samples)
         Ewhite(i + 1) = White(i + 1)
         Toggle Portb.i
         Waitms Acclim
     Next
     Serout Sensoutput , 1 , B , 5 , 9600 , 0 , 8 , 1
     Wait 5
     For I = 0 To 2
         Toggle Portb.i
         Waitms Acclim
         Black(i + 1) = Getreading(samples)
         Eblack(i + 1) = Black(i + 1)
         Toggle Portb.i
         Waitms Acclim
     Next
     Sensoutput = &HAA
     Serout Sensoutput , 1 , B , 5 , 9600 , 0 , 8 , 1

End Sub