'-------------------------------------------------------------------------------
'                                 Version Française
'                            (c) 2004 MCS Electronics
'                 Cette démo   montre un exemple de l'emploi de TWI
'                      Not all AVR chips have TWI (hardware I2C)
'-------------------------------------------------------------------------------

'The chip will work in TWI/I2C master mode
$regfile = "M128def.dat"       ' the used chip
$crystal = 8000000       ' frequency used

'-------I2C config ------------------------------------------------------
$lib "i2c_twi.lbx"       ' we do not use software emulated I2C but the TWI
Config Sda = Portd.1       ' I2C Data.
Config Scl = Portd.0       ' I2C Clock.
'-------LCD----if use--------------------------------------------------
 Config Lcd = 20 * 2
 Config Lcdpin = Pin , Db4 = Portf.2 , Db5 = Portf.3 , Db6 = Portf.4 , Db7 = Portf.5 , E = Portf.6 , Rs = Portf.7
 Cls
I2cinit   ' we need to set the pins in the proper state

Config Twi = 100000       ' wanted clock frequency
'will set TWBR and TWSR
'Twbr = 12                                                   'bit rate register
'Twsr = 0                                                    'pre scaler bits

Dim B As Byte , Xbyte As Byte
Dim Action As Byte , Xsend As Byte
Dim Index As Byte , Kword As Word , Jbyte As Byte
Dim Valuesingle As Single
Dim Value As Long , Klong As Long , Dummy As Long
Dim R1 As Single
Dim Arraywork(5) As String * 1
Dim Arrayreceived(5) As Byte
Action = 12       ' action to do by the slave 12=COS
Valuesingle = 1.151917217       'example :value in radian of 66°
Valuesingle = Valuesingle * 1000       'removing the dot
Value = Valuesingle
Gosub Decomposition
Do
      I2cstart
       I2cwbyte &H70       ' slave address write
       I2cwbyte Action       ' write choice
       For Jbyte = 1 To 4
            I2cwbyte Arraywork(jbyte)
        Next
       I2cstop
       If Err > 0 Then
         Locate 2 , 1 : Lcd "Error : " ; Err       ' show error status
       End If
       Waitms 50

       I2cstart
       I2cwbyte &H71
           For Xbyte = 1 To 4
             I2crbyte Arrayreceived(xbyte) , Ack
          Next

       I2crbyte Arrayreceived(5) , Nack
       I2cstop
         If Err > 0 Then
         Locate 2 , 1 : Lcd "Error : " ; Err       ' show error status
       End If
     Gosub Recomposition
     Locate 2 , 1 : Lcd Spc(20)
     Locate 2 , 1 : Lcd "rec: " ; R1
       Waitms 50       'wait a bit
Loop
End

Decomposition:
 Index = 0
         Kword = Highw(value)
          Jbyte = High(kword)       '1° quart du long
       Index = Index + 1
        Arraywork(index ) = Chr(jbyte)
         Jbyte = Kword       '2° quart du long
      Index = Index + 1
            Arraywork(index ) = Chr(jbyte)
          Kword = Value       'pour prendre le low word de ARG1
          Jbyte = High(kword)       '3° quart du long
      Index = Index + 1
            Arraywork(index ) = Chr(jbyte)
          Jbyte = Kword       '4° quart du long
      Index = Index + 1
            Arraywork(index ) = Chr(jbyte)
Return

Recomposition:
 Jbyte = Arrayreceived(4) : Klong = Jbyte
 Dummy = Arrayreceived(3) : Dummy = Dummy * 256 : Klong = Klong + Dummy
 Dummy = Arrayreceived(2) : Dummy = Dummy * 65536 : Klong = Klong + Dummy
 Dummy = Arrayreceived(1) : Dummy = Dummy * 16777216 : Klong = Klong + Dummy
           R1 = Klong
           R1 = R1 / 1000
Waitms 100
Return


'--------------------Jean-Pierre Duval 12-12-2005-------------------------
'                         coprocesseur mathématique I2C
' mathématic coprocessor I2C
'------------------------------------------------------------------------------

$regfile = "m8def.dat"
$crystal = 8000000
'
' port I2C SCL= C.5  to be TWI
' port I2C SDA= C.4
Dim J As Byte
Dim Choice As Byte , Dummy As Long , Jbyte As Byte

Dim Klong As Long
Dim Kword As Word
Dim Index As Byte       '
Dim R1 As Single
Dim Arrayreceived(5) As Byte
Dim Arraywork(4)as String * 1

' config LCD------------------------------------------------------------------------------
Config Lcdmode = Port       ' config  4 bit
Config Lcdpin = Pin , Db4 = Portd.3 , Db5 = Portd.2 , Db6 = Portd.1 , Db7 = Portd.0 , E = Portd.4 , Rs = Portd.5

Config Twislave = &H70 , Btr = 5 , Bitrate = 100000
'                                       Btr =choice + R1*'4byte,)

'Const Pi = 3.14159265358979 just a pleasure
'calculate PI
'Ms1 = Atn(1) * 4
Cls
Locate 1 , 1 : Lcd "M8 TWI-slave"
Wait 1
Cls
Enable Interrupts

'------------main-----------------------------
Do
  nop
Loop

End
'----les sub-routines slaves------------------
Twi_stop_rstart_received:
         'reception of Start and stop
Return


Twi_addressed_goread:
'master sent out slave address and will  send data
 Return

Twi_addressed_gowrite:
'Master will go write
 Return

Twi_gotdata:
'here the master send data, Twi_btw is a var which count the number of bytes
'received
'TWI is the var which stock the actual byte
'We need to make an array to collect data. We are here each time we receive a byte
Arrayreceived(twi_btw) = Twi
 If Twi_btw = 5 Then
    Choice = Arrayreceived(1)
     If Choice > 0 Then
          Jbyte = Arrayreceived(5) : Klong = Jbyte
           Dummy = Arrayreceived(4) : Dummy = Dummy * 256 : Klong = Klong + Dummy
           Dummy = Arrayreceived(3) : Dummy = Dummy * 65536 : Klong = Klong + Dummy
           Dummy = Arrayreceived(2) : Dummy = Dummy * 16777216 : Klong = Klong + Dummy
           R1 = Klong       'R1 is a string,   Klong= RI*1000 (do by the master)
           R1 = R1 / 1000       ' we devise by 1000 to match the real R1
Locate 2 , 1 : Lcd "rec:" ; R1
           Gosub Calcul
           Gosub Preparation
     End If
End If
Return
'   * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Twi_master_needs_byte:
' this label is needed when Master need response
'The var TWI will be the value sends back to the master
'twi_btr is define in the config.
For Jbyte = 1 To Twi_btr
 Twi = Arraywork(jbyte)
Next
  Return
'   * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Twi_master_need_nomore_byte:
'when the mast has all bytes received this label will be called
Return

Preparation:
' this label is called to prepare the byte to send back
     R1 = R1 * 1000       'transforme the single in long again
     Klong = R1
 Index = 0
        Kword = Highw(klong)
          Jbyte = High(kword)       '1° quart du long
       Index = Index + 1
        Arraywork(index ) = Chr(jbyte)
         Jbyte = Kword       '2° quart du long
      Index = Index + 1
            Arraywork(index ) = Chr(jbyte)
          Kword = Klong       'pour prendre le low word
          Jbyte = High(kword)       '3° quart du long
      Index = Index + 1
            Arraywork(index ) = Chr(jbyte)
          Jbyte = Kword       '4° quart du long
      Index = Index + 1
            Arraywork(index ) = Chr(jbyte)
Return

Calcul:
Select Case Choice
      Case 1       ' exponentielle -----------------------------
            R1 = Exp(r1)
      Case 2       ' logarithme   -----------------------
             R1 = Log(r1)
      Case 3       ' logarithme   base 10--------------
             R1 = Log10(r1)
      Case 4       'Sqr---------------------------------
             R1 = Sqr(r1)
      '   SQR-single----------------------------------------------------------
      'Case 5       'puissance instruction POWER--R1^ R2
      '    R1 = Power(r1 , R2 )
     Case 10       'deg2rad-------------------------
          R1 = Deg2rad(r1)
     Case 11       'rad2deg----------------------
            R1 = Rad2deg(r1)
     Case 12       ' cos---------
          R1 = Cos(r1)
     Case 13       ' sin---------
          R1 = Sin(r1)
     Case 14       ' tan----------------------------------
          R1 = Tan(r1)
      Case 15       '   arctangente-------------------
                R1 = Atn(r1)
        Case 16       ' cos hyperbolique
           R1 = Cosh(r1)
        Case 17       'sin hyperbolique
           R1 = Sinh(r1)
        Case 18       'tangente hyperbolique
           R1 = Tanh(r1)
     '        Case 19       ' atn2-----------------------------
     '          R1 = Atn2(r1 , R2)
        Case 20       'Arc-sinus---------------------
            R1 = Asin(r1)
        Case 21       ' arc cosinus----------------------
            R1 = Acos(r1)
         Case 30       'int---------------------
            R1 = Int(r1)
         Case 31       ' frac-------------------------
            R1 = Frac(r1)
     '         Case 32       'modulo---------------------------
     '            R1 = R1 Mod R2
         Case 33
           R1 = R1
           Case Else
                Return
     End Select
Return