'-------------------------------------------------------------------
'                       TIM1.BAS  Dzehzahlmesser mit 90S8515
'                      Messung der Impulszeiten mit T1
'-------------------------------------------------------------------
 $regfile = "8515def.dat"
 $crystal = 4000000                                         ' 4 MHz Takt

 Config Pinb.3 = Input


 Dim Impulse As Byte
 Dim V As Long
Dim W As Long
Dim W1 As Long
Dim W2 As Long
Dim W3 As Long
Config Timer1 = Timer , Prescale = 256 , Capture Edge = Rising


Config Lcdpin = Pin , Db4 = Portc.4 , Db5 = Portc.5 , Db6 = Portc.6 , Db7 = Portc.7 , Rs = Portc.3 , E = Portc.1
Config Lcd = 16 * 2


 On Ovf1 Ontvf1
 On Icp1 Oncapture
 Enable Icp1
 Enable Ovf1

 Enable Interrupts

     Main:

  V = 0
  W3 = 0

 Impulse = 0

 Cls
      Cursor Off

      Lcd "Drehzahl"

      Locate 2 , 1

      Lcd V

      Lcd " UpM    "



 Tcnt1l = 0                                                 ' Loesche Timer1
 Tcnt1h = 0


 Do

   Loop

   End


Oncapture:

Disable Icp1
Disable Ovf1

 W3 = Timer1

  Timer1 = 0

 W2 = W2 + W3

Incr Impulse

   If Impulse = 10 Then                                     ' 10 Impulse Zaehlen damit ruhiger Zaehler


      W1 = W2 * 3200                                        '    Taktzeit bei Presc. 256 + 8,0 MHz
                                                                 ' wg. der t 32 us

    W = W1 / 100                                            ' Dann das ganze durch 100 Teilen
                                                             ' 1 / W2 * 60 wird ersetzt durch
                                                             '
                                                             ' 600000000 erspart das malnehmen mit 6
      V = 600000000 / W



      Locate 2 , 1

      Lcd V

      Lcd " UpM     "

       W = 0
       W2 = 0
       W3 = 0
       V = 0
          Impulse = 0

        Else

        End If

       Enable Icp1
      Enable Ovf1

     Return


     Ontvf1:

      Disable Icp1
      Disable Ovf1

      V = 0

      Locate 2 , 1

      Lcd V

      Lcd " UpM     "

       W = 0
       W2 = 0
       V = 0

       Enable Icp1
      Enable Ovf1
      Timer1 = 0
     Return