' **********************************************************************
' ** Program: k51terme.BAS    -    Version : 1.1   -   20 June 2005   **
' ** Compiler : Bascom AVR IDE - LIB 1.11.7.4                         **
' ** Board : GMB HR168 and GMM AM128 + K51-AVR                        **
' ** Society: grifo(r) ITALIAN TECHNOLOGY                             **
' ** Via Dell' Artigiano 8/6          40016 San Giorgio di Piano (BO) **
' ** Tel.+39 051 892 052     Fax +39 051 893 661                      **
' ** http://www.grifo.com    http://www.grifo.it                      **
' ** Written by:  Graziano Gaiba                                      **
' **********************************************************************
'
' 20.06.05 - Rel 1.1 By Graziano Gaiba
' This demo allows to drive an I2C BUS peripheral on board of K51-AVR,
' DS1621, through mini-BLOCK module GMB HR168 and grifo(r) mini module.
' DS1621 is a programmable digital thermometer, whose resolution is half
' Celsius degreese, all the operations of programming and temperature
' acquisition are performed through synchronous serial interface I2C BUS.
' This demo shows the temperature acquired on the 7 segments display of
' K51-AVR.
'
'
'
' !!!!!!!!!!!!!!!!!!!!!!!!!!! IMPORTANT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
' In menu Options | Compiler | Chip, set:
'
' Chip:       M128
' HW Stack:   at least 64
' Soft Stack: at least 32
' Framesize:  at least 64
'
'
$regfile = "m128def.dat"
$crystal = 7372800
$baud = 19200
'
'********************* Constants declaration ***************************
'
' Time out in case a TWI command receives no response
Const Ee_timeout = 50000
' TWI reading options
Const Twi_ack = 1
Const Twi_nack = 0

Const Saa1064 = &H38                                        ' Slave address SAA1064
Const Wsaa1064 = &H70                                       ' Slave address SAA1064 in Write
Const Rsaa1064 = &H71                                       ' Slave address SAA1064 in Read
'****************** Addresses list for Saa1064 *************************
Const Ctb = 0                                               ' Address Control byte
Const Dig1 = 1                                              ' Address Digit 1
Const Dig2 = 2                                              ' Address Digit 2
Const Dig3 = 3                                              ' Address Digit 3
Const Dig4 = 4                                              ' Address Digit 4
'
' **********************************************************************
'
Const Ds1621 = &H4C                                         ' Slave address DS1621
Const Wds1621 = &H98                                        ' Slave address DS1621 in Write
Const Rds1621 = &H99                                        ' Slave address DS1621 in Read
' ***************** Commands list of DS1621 ****************************
Const Cfg = &HAC                                            ' R/W Config register of DS1621
Const Rtemp = &HAA                                          ' read temperature 2 bytes
Const Strct = &HEE                                          ' Start temperature conversion
Const Stpct = &H22                                          ' Stop temperature conversion
'*********************** Variables declaration *************************
'
'Generic use
Dim T1 As Byte , T2 As Byte , I2cstatus As Byte

Dim Cifc As Byte                                            ' figure of hundreds
Dim Cifd As Byte                                            ' figure of decines
Dim Cifu As Byte                                            ' figure of units
Dim Getdati(2) As Byte                                      ' 2 bytes vector
'
'********************** Procedure declarations *************************
'
' Send a command to TWI interface, wait for it to complete and returns status
Declare Function Twi_cmd(byval Cmd As Byte) As Byte
Declare Sub Twiinit(byval Clockrate As Byte)                ' Initialize TWI hardware interface
Declare Function Twistart() As Byte                         ' Generate a start by TWI hardware interface
Declare Function Twiwbyte(byval Dato As Byte) As Byte       ' Send a byte by TWI hardware interface
Declare Function Twirbyte(twi_data As Byte , Byval Assert_ack As Byte) As Byte       ' Read a byte from TWI hardware interface
Declare Function Twistop() As Byte                          ' Generate a stop by TWI hardware interface

Declare Sub Check_ready()
Declare Function Check_ready_2() As Byte
Declare Sub Iniz                                            ' Peripherals initialization
Declare Sub Temperatura()                                   ' reads temperature
Declare Sub Cifre(byval Valore As Byte )
                                          ' converts a number in 2 HEX figures
Declare Function Digit(byval Dig As Byte ) As Byte          ' Converts a number in range
                                               ' 0 to 9 in 7 segments
Declare Sub Vis_temp(byval Th As Byte , Byval Tl As Byte)   ' visualizes temperature
'
'*************************** Main program ******************************
'
Main:
   Print Chr(12)                                            ' Clears the screen
   Print "Demo of thermometer DS1621."
   Print
   Call Check_ready()
   Print "7 segments displays show temperature measured."
   Call Iniz()                                              ' initializations
   Do
      Call Temperatura()                                    ' read temperature
      T1 = Getdati(1)                                       ' get high byte
      T2 = Getdati(2)                                       ' get low byte
      Call Vis_temp(t1 , T2)                                ' visualize temperature
   Loop
End
'
'**************************** Program end ******************************
'
'
'**************************** Procedures *******************************
'
' ********************** Peripherals initialization ********************
' This procedure performs all the system initializations.
' Parameters:
' Input : nothing
' Output : nothing
' ************************************************************************
'
Sub Iniz()                                                  ' Peripherals initialization

   Local Valore As Byte

   ' Initialize hardware I2C BUS interface at about 72 kHz
   Call Twiinit(72)

   Do
      I2cstatus = Twistart()                                ' Start sequence for I2CBUS
      I2cstatus = Twiwbyte(rsaa1064)
      I2cstatus = Twirbyte(valore , Twi_nack)               ' Read the status register
      I2cstatus = Twistop()
      'I2creceive Rsaa1064 , Valore
   Loop Until Valore = 0                                    ' Wait for SAA1064 to turn on

   I2cstatus = Twistart()                                   ' Start sequence for I2CBUS
   I2cstatus = Twiwbyte(wsaa1064)                           ' Communicate the Slave address
   I2cstatus = Twiwbyte(ctb)                                ' Point to control register
   I2cstatus = Twiwbyte(&B00100111)                         ' bit0 =1 dynamic mode
                                          ' bit1 =1 digit 1+3 not blanked
                                          ' bit2 =1 digit 2+4 not blanked
                                          ' bit3 =0 no test segment
                                          ' bit4 =0 no 3mA segment current
                                          ' bit5 =1 6mA segment current
                                          ' bit6 =0 no 12mA segment current
                                          ' bit7 =0 indifferent
   I2cstatus = Twiwbyte(0)                                  ' set DY1 off
   I2cstatus = Twiwbyte(0)                                  ' set DY2 off
   I2cstatus = Twiwbyte(0)                                  ' set DY3 off
   I2cstatus = Twiwbyte(0)                                  ' set DY4 off
   I2cstatus = Twistop()


   I2cstatus = Twistart()                                   ' Start sequence for I2CBUS
   I2cstatus = Twiwbyte(wds1621)                            ' point to Configuration register
   I2cstatus = Twiwbyte(cfg)
   I2cstatus = Twistop()
   'I2csend Wds1621 , Cfg
   I2cstatus = Twistart()                                   ' Start sequence for I2CBUS
   I2cstatus = Twiwbyte(rds1621)
   I2cstatus = Twirbyte(valore , Twi_nack)
   I2cstatus = Twistop()
   'I2creceive Rds1621 , Valore                              ' read Configuration register
   Valore = Valore And 1                                    ' mask Bit 0
   If Valore = 1 Then                                       ' if temperature conversion not actived
      I2cstatus = Twistart()                                ' Start sequence for I2CBUS
      I2cstatus = Twiwbyte(wds1621)                         ' Communicate the Slave address
      I2cstatus = Twiwbyte(cfg)                             ' point to Configuration register
      I2cstatus = Twiwbyte(&B00001010)                      ' write Configuration register
                                          ' bit1= 1 polarity "1"
                                          ' bit0= 0 continuous conversion
      I2cstatus = Twistop()
      Waitms 50                                             ' delay
  End If
   I2cstatus = Twistart()                                   ' Start sequence for I2CBUS
   I2cstatus = Twiwbyte(wds1621)                            ' read Configuration register
   I2cstatus = Twiwbyte(strct)
   I2cstatus = Twistop()
   'I2csend Wds1621 , Strct                                  ' start temperature conversion
End Sub
'
'
' *************************** read temperature ***************************
' This procedure reads the value of the temperature.
' Parameters:
' Input : nothing
' Output : Getdati(0), contains TH, high byte of temperature
'          Getdati(1), contains TL, low byte of temperature
' ************************************************************************
'
Sub Temperatura                                             ' read temperature

  Local Temp1 As Byte , Temp2 As Byte

   ' ask to read temperature
   I2cstatus = Twistart()                                   ' Start sequence for I2CBUS
   I2cstatus = Twiwbyte(wds1621)                            ' read Configuration register
   I2cstatus = Twiwbyte(rtemp)
   I2cstatus = Twistop()
   'I2csend Wds1621 , Rtemp
   I2cstatus = Twistart()                                   ' Start sequence for I2CBUS
   I2cstatus = Twiwbyte(rds1621)
   I2cstatus = Twirbyte(temp1 , Twi_ack)
   I2cstatus = Twirbyte(temp2 , Twi_nack)
   I2cstatus = Twistop()
   Getdati(1) = Temp1
   Getdati(2) = Temp2
   'I2creceive Rds1621 , Getdati(1) , 0 , 2                  ' read TH and TL
End Sub
'
'
' *********** Converts a figure in range from 0 to F in 7 segments *****
' This procedure converts a figure in range from 0 to 9 in 7 segments format, if
' value is equal to or greater than 11 the display is off, if equal to 10 a
' negative sign is displayed.
' Parameters:
' Input : dig as byte, value from 0 to 9
' Output : byte, value in 7 segments format.
' ************************************************************************
'
Function Digit(byval Dig As Byte ) As Byte                  ' Converts a figure in range from 0 to 9 in 7 segments

   Local Valore As Byte

   If Dig < 10 Then                                         ' if number is lower thawn 10
      Valore = Lookup(dig , Tab_7seg)                       ' read value from table
   Else
      If Dig > 10 Then                                      ' if true trun off dispaly
         Valore = 0
      Else                                                  ' if = 10
         Valore = 64                                        ' show "-"
      End If
   End If

   Digit = Valore

End Function
'
'
' ***************** Converte 1 byte in two "temperature" figures *************
' This procedure converts 1 byte from 0 to 255 in a temperature, that is a
' value from 0 to 125 means positive centigrad degreeses (+0..+125), while a
' value from 255 to 201 means negative centigrad degreeses (-0..-55), bit 7 is
' the sign bit, negative degreeses are obtained complementing.
' E.g.: Not 255=0, Not 201=54
' Parameters:
' Input : Valore as byte, value from 0 to 255
' Uscita : Cifc As Byte , Cifd As Byte , Cifu As Byte, which contain hundreds,
'    decines and unitsofthe temperature.
' *****************************************************************************
'
Sub Cifre(valore As Byte )
   If Valore > 127 Then                                     ' temperature results negative
      Cifc = 10                                             ' minus sign actived
      Valore = Not Valore                                   ' complement the value
   Else
      If Valore > 99 Then                                   ' if positive, over 99
         Cifc = 1                                           ' activate figure "1" of hundreds
         Valore = Valore - 100                              ' subtract 100
      Else
         Cifc = 11                                          ' not over 99, turn off the figure
                                          ' of hundreds
      End If
   End If
   If Valore > 9 Then                                       ' freater than 9
      Cifd = Valore / 10                                    ' calculate figure of decines
      Cifu = Cifd * 10                                      ' calculate figure of units
      Valore = Valore - Cifu
      Cifu = Valore
   Else
      If Cifc = 11 Then                                     ' lower than 9 and figure of hundreds off
         Cifd = 11                                          ' turn off figure of decines
      Else
         If Cifc = 10 Then                                  ' lower than 9, and negative temperature
            Cifd = 11                                       ' turn off figure of decines
         Else
            Cifd = 0                                        ' lower than 9 and figure of hundreds on
                                          ' show a zero
         End If
      End If
      Cifu = Valore                                         ' save value of units
   End If
End Sub
'
'
' *********************** Temperature visualization ***********************
' This procedure allows to visualize the temperature stored in 2 bytes
' TH high byte and TL low byte
' TL indicates helf degree 0 or 128 (0 .. 0.5).
' TH indicates degreeses from 0 to 125 (+0..+125), and from 255 to 21 ( -0..-54).
' Parameters:
' Input : TH as byte, high byte value
'         TL as byte, low byte value
' Output : nothing
' ************************************************************************
'
Sub Vis_temp(byval Th As Byte , Byval Tl As Byte)           ' Temperature visualization

   Local Valore As Byte

   I2cstatus = Twistart()                                   ' Start sequence for I2CBUS
   I2cstatus = Twiwbyte(wsaa1064)                           ' Communicate the Slave address
   I2cstatus = Twiwbyte(dig1)                               ' point to display 1 (DY1)

   Call Cifre(th )                                          ' convert in 3 figures
   Valore = Digit(cifc)                                     ' convert figure of hundreds in 7 segments
   I2cstatus = Twiwbyte(valore)                             ' output to the first display

   Valore = Digit(cifd)                                     ' convert figure of decines in 7 segments
   I2cstatus = Twiwbyte(valore)

   Valore = Digit(cifu)                                     ' convert figure of units in 7 segments
   Valore = Valore Or 128                                   ' turn on decimal point
   I2cstatus = Twiwbyte(valore)                             ' output to third terzo display

   If Tl = &H80 Then                                        ' visualize the half degree
      Valore = Digit(5)                                     ' convert figure of units in 7 segments
   Else
      Valore = Digit(0)                                     ' convert figure of units in 7 segments
   End If
   I2cstatus = Twiwbyte(valore)                             ' output to fourth display
   I2cstatus = Twistop()                                    ' Stop sequence for I2CBUS
End Sub
'
'******************************************************************************
'*                     I2C BUS hardware management procedures                 *
'******************************************************************************
'
'
'
' Writes command passed in parameter cmd into control register TWI and waits
' for the completion of operation, then reads the status of TWI interface and
' returns it.
'
Function Twi_cmd(byval Cmd As Byte) As Byte

  Local Time_out As Word , I As Byte

  Twcr = Cmd                                                ' Writes the command
  Time_out = 0                                              ' Timeout counter
  Do
     Incr Time_out                                          ' Increment counter
  Loop Until Twcr.twint = 1 Or Time_out = Ee_timeout
  ' Reads status and masks not significant bits
  I = Twsr
  I = I And &HF8
  Twi_cmd = I
End Function
'
'
' Initializes hardware TWI interface
'
Sub Twiinit(byval Clockrate As Byte)
   Twsr = Twsr And &HFC                                     ' No prescaler
   Twbr = Clockrate                                         ' Set clock rate
End Sub
'
'
' Send start for hardware TWI interface
'
Function Twistart() As Byte
   Twistart = Twi_cmd(&Ha4)                                 ' Start
End Function
'
'
' Send byte to hardware TWI interface
'
Function Twiwbyte(byval Dato As Byte) As Byte
   Twdr = Dato                                              ' Write data
   Twiwbyte = Twi_cmd(&H84)
End Function
'
'
' Read byte from hardware TWI interface
'
Function Twirbyte(twi_data As Byte , Byval Assert_ack As Byte) As Byte
   If Assert_ack = 1 Then
      Twirbyte = Twi_cmd(&Hc4)
   Else
      Twirbyte = Twi_cmd(&H84)
   End If

   Twi_data = Twdr
End Function
'
'
' Send stop on hardware TWI interface.
' Returns 0 if there are no errors, a value different from 0 in case of
' timeout.
'
Function Twistop() As Byte

   Local Time_out As Word

   Twcr = &H94                                              ' Stop
               ' Waits for the stop completer or timeout
   Time_out = 0
   Do
     Incr Time_out
   Loop Until Twcr.twsto = 0 Or Time_out = Ee_timeout

   If Time_out = Ee_timeout Then
      Twistop = 1
   Else
      Twistop = 0
   End If

End Function
'
'******************************************************************************
'*                              Generic procedures                            *
'******************************************************************************
'
'
'
' Supporting function for Check_ready().
'
Function Check_ready_2() As Byte

  Local Time_out As Word , I As Byte

  Time_out = 0                                              ' Timeout counter
  Do
     Incr Time_out                                          ' Increment counter
  Loop Until Twcr.twint = 1 Or Time_out = Ee_timeout
  I = Twsr
  I = I And &HF8
  Check_ready_2 = I
End Function
'
'
' Check for card ready
'
Sub Check_ready()

   Local Check As Byte , Test As Byte

   Do                                                       ' Loop to check for card ready
      Twsr = Twsr And &HFC
      Check = Twdr Or &HF4
      Test.4 = Not Check.3
      Twbr = 72
      Twcr = &HA4
      Check = Check_ready_2()
      Test = Check Or Twcr
      If Check = &H09 Then
         Test = &H67
      Else
         Test.1 = Not Test.1
      End If
      Twdr = &HA0
      Twcr = &H84
      Check = Check_ready_2()
      Twcr = &H94
      Waitms 27
   Loop Until Check = &H18 Or Test <> 1
   Twcr.twen = 0
End Sub
'
' ***** Conversion table for 7 segments figure in the range from 0 to 15 *******
Tab_7seg:
' num.  0      1      2      3      4      5      6      7      8      9
Data &H3F , &H06 , &H5B , &H4F , &H66 , &H6D , &H7D , &H07 , &H7F , &H6F
' ******************************************************************************
'