$regfile = "m8def.dat"
$crystal = 16000000

'20070127 v00 skeleton test lcd and i2c led flash
'20070128 v01 basic dds calculation (clumsy!) and display/button control
'20070128 v02 dds clock set in menu
'20070130 v03 dds clock multiplier in menu
'20070131 v04 finishing touches
'20070201 v05 documented
'20070206 v06 choose between pcf8574 and pcf8574a i/o expander
'20070212 v07 changed i2c pinning
'20070213 v08 corrected error in ddsclock frequency menu setting
'20070221 v09 internal pull-up on pcf8574type pin
'20070318 v10 loop-led on portd7.7
'20070328 v11 longer buttons debounce time (20->40msec)
'20070401 v12 buttons now read out in polling mode directly on portd

'-------- update version lcd!
'
'Charlos Potma, PA3CKR
'Bascom program to control an AD9951 DDS.
'An I2C I/O port expander IC type PCF8574A is used to read eight buttons:
'button 1 increases dds output frequency with step value
'button 2 decreases dds output frequency with step value
'button 3 increases frequency stepvalue (1Hz..10MHz)
'button 4 decreases frequency stepvalue (1Hz..10MHz)
'button 5 cycles through 10 frequency memories
'button 6 stores the dds frequency in the current memory
'button 7 recalls the frequency from the current memory
'button 8 starts a simple menu:
'-first, a dds reference clock multiplier can be chosen: either 1 (no multiplication)
' or a multiplier in the range 4..20
'-second, the basic dds refence clock frequency (before multiplication)
' can be changed using button 1..4
' the resulting multiplier and dds basic reference clock frequency are stored in eeprom
'When changing the dds basic reference clock frequency, please note that you must
'keep in mind that the resulting dds reference clock is kept within the AD9951
'limits. The program does not do that to allow you a fair amount of overclocking!
'My AD9951 was ok with a 50MHz basic reference and a multiplier of 15,
'resulting in a reference clock of 750MHz...
'Note that this program sets the vco range control bit if reference clock
'is higher than 250MHz.
'
'When the ATMega8 is programmed, the eeprom is probably empty, the AD9951 will
'generate frequency 0Hz.
'Then switch on the ATMega8 while one of the buttons is pressed,
'until the LCD reports : "Deflts restored ".
'The default list is shown below in the source, see   'Write Default Data To Eeprom
'

'Config LCD
Config Lcd = 16 * 2
Config Lcdpin = Pin , Db4 = Portb.0 , Db5 = Portb.1 , Db6 = Portb.2 , Db7 = Portb.3 , E = Portb.4 , Rs = Portb.5

Config Portd = Input
Config Pinc.0 = Output
Config Pinc.1 = Output
Config Pinc.2 = Output
Config Pinc.3 = Output
Config Pinc.5 = Output
Ad9951reset Alias Portc.0
Ad9951sclk Alias Portc.1
Ad9951sdio Alias Portc.2
Ad9951ioupdate Alias Portc.3
Led Alias Portc.5

'AD9951 ftw0 register write address
Const Ad9951ftw0 = &B0000100
'AD9951 control function register number 2 address
Const Ad9951cfr2 = &B00000001
'AD9951 ref clock multiplier low limit
Const Ad9951rcmlow = 4
'AD9951 ref clock multiplier high limit
Const Ad9951rcmhigh = 20
'AD9951 vco range control trip (sets bit 2 in cfr2 when ddscock > 250MHz)
Const Ad9951vcohigh = 250000000

'Buttons on Portd
'Frequency up button is on bit0 of Portd
Const Frequp = &B11111110
'Frequency down button is on bit1 of Portd
Const Freqdn = &B11111101
'Step up button is on bit2 of Portd
Const Stepup = &B11111011
'Step down button is on bit3 of Portd
Const Stepdn = &B11110111
'Memory button is on bit4 of Portd
Const Mem = &B11101111
'Memory store button is on bit5 of Portd
Const Memstr = &B11011111
'Memory recall button is on bit6 of Portd
Const Memrcl = &B10111111
'Menu button  is on bit7 of Portd
Const Menu = &B01111111

'Number of frequency memories
Const Freqmemmax = 10
'Number of frequency stepvalues in data block (minus 1)
Const Fstepsnum = 7
'Default Fsteps data table index
Const Fstepsdefault = 1
'constant used in dds frequency calculation
'2^31
Const Twop31 = 2147483648
'2^9
Const Twop9 = 512
'2^8
Const Twop8 = 256

'AD9951 register address
Dim Ddsregaddress As Byte
'temporary storage
Dim Tmpword As Word
Dim Tmpint As Integer
'1 if there is work to do in main loop
Dim Doflag As Bit
'last memory place used
Dim Memdispflag As Bit
'1 if menu button has been pressed
Dim Menuflag As Bit
'multiplier entry flag
Dim Multflag As Bit
'last frequency memory number used
Dim Lastmemnum As Byte
'AD9951 ref clock multiplier temporary
Dim Ddsrcmtmp As Byte
'AD9951 ref clock multiplier
Dim Ddsrcm As Byte
'AD9951 dds output frequency
Dim Ddsfrequency As Long
'AD9951 dds output frequency as double
Dim Ddsfrequencydbl As Double
'AD9951 temporary dds output frequency
Dim Tmpddsfrequency As Long
'index in frequency steps array
Dim Ddsfreqstepindex As Byte
'Frequency step value
Dim Ddsfreqstep As Long
'frequency step value exponent
Dim Ddsfsexp As Integer
'high limit dds frequency as long
Dim Ddshighlng As Long
'low limit dds frequency as long
Dim Ddslowlng As Long
'AD9951 basic clock frequency (external clock frequency)
Dim Ddsclockbasic As Long
'AD9951 clock frequency (after multiplication with ref clock multiplier)
Dim Ddsclock As Long
'AD9951 clock frequency as double
Dim Ddsclockdbl As Double
'AD9951 tuning word as a double
Dim Ftwdbl As Double
'AD9951 tuning word as single
Dim Ftwsgl As Single
'AD9951 tuning word as long
Dim Ftwlng As Long
'constant used in tuning word calculation
Dim Cftwdbl As Double
'strings used in formatting frequency info for lc display
Dim Tmpstr As String * 12
Dim Tmpddsfreqstr As String * 12
Dim Ddsfreqstr As String * 12
'cursor blink position to indicate fstep value
Dim Blinkposition As Byte
'used in strin manipulations
Dim Strlen As Integer
'holds button bit pattern
Dim Buttons As Byte

'do not use first eeprom byte, could be trashed during a reset
Dim Eedummy As Eram Byte
'last frequency saved
Dim Eelastmemnum As Eram Byte
'last frequency step used
Dim Eelastfreqstepindex As Eram Byte
'frequency memories
Dim Eefrequencies(freqmemmax) As Eram Long
'current AD9951 basic clock frequency
Dim Eeddsclock As Eram Long
'ref clock multiplier
Dim Eeddsrcm As Eram Byte
'current constant used in dds tuning word calculation
'Dim Eecftwdbl As Eram Long


'sub to handle buttons
Declare Sub Handlebuttons
'setup AD9951 with ref clock multiplier
Declare Sub Setad9951mult
'sub to program AD9951
Declare Sub Progad9951
'sub to calculate constant used in tuning word calculation
Declare Sub Calccftwconstant
'sub to calculate dds frequency tuning word
Declare Sub Calccftw
'sub to update lcdisplay, calc ftw
Declare Sub Updddsdisp
'sub to reset AD9951
Declare Sub Resetad9951
'calculate frequency step value and cursor position
Declare Sub Calcstpexp
'make frequency display string
Declare Sub Calcfreqstr

'enable weak pull-up on portd
Portd = 255
'clear lcd, report version
Cls
Cursor Off
Lcd "AD9951 v12"
Locate 2 , 1
Lcd "PA3CKR"
Wait 1
Cls

''If any of the buttons is pressed at power-up, restore memory defaults
If Pind <> 255 Then
  'Write Default Data To Eeprom
  Eelastmemnum = 1
  Eelastfreqstepindex = 1
  Eefrequencies(1) = 10000000
  Eefrequencies(2) = 11000000
  Eefrequencies(3) = 12000000
  Eefrequencies(4) = 13000000
  Eefrequencies(5) = 14000000
  Eefrequencies(6) = 15000000
  Eefrequencies(7) = 16000000
  Eefrequencies(8) = 17000000
  Eefrequencies(9) = 18000000
  Eefrequencies(10) = 19000000
  Eeddsclock = 50000000
  Eeddsrcm = 1
  Cls
  Lcd "Deflts restored "
  Wait 3
End If

Cls
Lcd "Resetting AD9951"
Call Resetad9951
Wait 1

Lastmemnum = Eelastmemnum
Ddsfrequency = Eefrequencies(lastmemnum)
Ddsfreqstepindex = Eelastfreqstepindex
'calculate frequency step value and cursor position
Call Calcstpexp

Ddsclockbasic = Eeddsclock
Ddsrcm = Eeddsrcm
Ddsclock = Ddsclockbasic * Ddsrcm
Cls
Lcd "Bclck: " ; Ddsclockbasic
Locate 2 , 1
Lcd "Rcm  : " ; Ddsrcm
Wait 3
'set dds low limit to 100kHz
Ddslowlng = 100000
'set dds high limit to 40% of ddsclock
Ddshighlng = Ddsclock / 10
Ddshighlng = Ddshighlng * 4

Reset Doflag
Reset Menuflag
Reset Memdispflag

Call Updddsdisp
Call Calccftwconstant
Call Calccftw
Call Setad9951mult
Call Progad9951

'main loop starts here
Do
  'show we are alive...
  Toggle Led
  'read buttons
  Buttons = Pind
  If Buttons <> 255 Then
    'yes, a button was pressed
    Set Doflag
    Waitms 200
  End If
  If Doflag = 1 Then
    Reset Doflag
    Call Handlebuttons
    'update lc display
    Call Updddsdisp
    'calculate new tuning word
    Call Calccftw
  End If
  'program multiplier
  Call Setad9951mult
  'program AD9951 frequency
  Call Progad9951
  'Locate 2 , 1
  'Lcd Ddsrcm ; " " ; Ftwlng
  Waitms 10
Loop

'#############################subroutines follow################################

Sub Handlebuttons
  'Frequency up button
  If Buttons = Frequp Then
    Reset Memdispflag
    If Menuflag = 1 Then
      'increase dds clock frequency
      Ddsclockbasic = Ddsclockbasic + Ddsfreqstep
      Ddsclock = Ddsclockbasic * Ddsrcm
      'set dds high limit to 40% of ddsclock
      Ddshighlng = Ddsclock / 10
      Ddshighlng = Ddshighlng * 4
      Call Calccftwconstant
    Elseif Multflag = 1 Then
      If Ddsrcm = 1 Then
        Ddsrcm = 4
      Else
        Ddsrcmtmp = Ddsrcm + 1
        If Ddsrcmtmp <= Ad9951rcmhigh Then
          'increase multiplier
          Ddsrcm = Ddsrcmtmp
        End If
      End If
      Call Setad9951mult
      Ddsclockbasic = Eeddsclock
      Ddsclock = Ddsclockbasic * Ddsrcm
      'set dds high limit to 40% of ddsclock
      Ddshighlng = Ddsclock / 10
      Ddshighlng = Ddshighlng * 4
      Call Calccftwconstant
    Else
      'increase dds frequency
      Tmpddsfrequency = Ddsfrequency + Ddsfreqstep
      If Tmpddsfrequency <= Ddshighlng Then
        Ddsfrequency = Tmpddsfrequency
      End If
    End If
  End If

  'Frequency down button
  If Buttons = Freqdn Then
    Reset Memdispflag
    If Menuflag = 1 Then
      'decrease dds clock frequency
      Ddsclockbasic = Ddsclockbasic - Ddsfreqstep
      Ddsclock = Ddsclockbasic * Ddsrcm
      'set dds high limit to 40% of ddsclock
      Ddshighlng = Ddsclock / 10
      Ddshighlng = Ddshighlng * 4
      Call Calccftwconstant
    Elseif Multflag = 1 Then
      If Ddsrcm = 4 Then
        Ddsrcm = 1
      Else
        Ddsrcmtmp = Ddsrcm - 1
        If Ddsrcmtmp >= Ad9951rcmlow Then
          'decrease multiplier
          Ddsrcm = Ddsrcmtmp
        End If
      End If
      Call Setad9951mult
      Ddsclockbasic = Eeddsclock
      Ddsclock = Ddsclockbasic * Ddsrcm
      'set dds high limit to 40% of ddsclock
      Ddshighlng = Ddsclock / 10
      Ddshighlng = Ddshighlng * 4
      Call Calccftwconstant
    Else
      'decrease dds frequency
      Tmpddsfrequency = Ddsfrequency - Ddsfreqstep
      If Tmpddsfrequency >= Ddslowlng Then
        Ddsfrequency = Tmpddsfrequency
      End If
    End If
  End If

  'Frequency stepvalue up button
  If Buttons = Stepup Then
    Reset Memdispflag
    Reset Multflag
    'increase step frequency
    If Ddsfreqstepindex < Fstepsnum Then
      Ddsfreqstepindex = Ddsfreqstepindex + 1
      Call Calcstpexp
    End If
  End If

  'Frequency stepvalue down button
  If Buttons = Stepdn Then
    Reset Memdispflag
    Reset Multflag
    'decrease step frequency
    If Ddsfreqstepindex > 0 Then
      Ddsfreqstepindex = Ddsfreqstepindex - 1
      Call Calcstpexp
    End If
  End If

  'Memory button (do only if not in menu)
  If Buttons = Mem Then
    Reset Multflag
    If Menuflag = 1 Then
      'we were in menu mode, jump out
      Ddsclock = Eeddsclock
      Reset Menuflag
    Else
      If Memdispflag = 0 Then
        Set Memdispflag
      Else
        'cycle through memories
        If Lastmemnum = Freqmemmax Then
          Lastmemnum = 1
        Else
          Lastmemnum = Lastmemnum + 1
        End If
        Set Memdispflag
      End If
    End If
  End If

  'Store button
  If Buttons = Memstr Then
    If Menuflag = 1 Then
      'we were in menu mode, jump out
      Ddsclock = Eeddsclock
      Reset Menuflag
    Else
      'store frequency in current memory
      Eelastmemnum = Lastmemnum
      Eefrequencies(lastmemnum) = Ddsfrequency
      Cls
      Locate 1 , 1
      Lcd "Stored"
      Reset Memdispflag
      Wait 1
    End If
  End If

  'Recall button
  If Buttons = Memrcl Then
    If Menuflag = 1 Then
      'we were in menu mode, jump out
      Ddsclock = Eeddsclock
      Reset Menuflag
    Else
      'recall frequency from current memory
      Eelastmemnum = Lastmemnum
      Ddsfrequency = Eefrequencies(lastmemnum)
      Call Progad9951
      Cls
      Locate 1 , 1
      Lcd "Recalled"
      Reset Memdispflag
      Wait 1
    End If
  End If

  'Menu button
  If Buttons = Menu Then
    'always reset memory mode
    Reset Memdispflag
    If Multflag = 1 Then
      Reset Multflag
      Set Menuflag
    Else
      If Menuflag = 1 Then
        'we were in menu mode, save clock frequency and exit
        Reset Menuflag
        'store new ref clock frequency and multiplier
        Eeddsclock = Ddsclockbasic
        Eeddsrcm = Ddsrcm
        Cls
        Lcd "Store dds clock"
        Locate 2 , 1
        Lcd "Store dds rcm"
        Wait 1
      Else
        'we were in normal mode, set menu flag
        Set Multflag
      End If
    End If
  End If
End Sub

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

Sub Setad9951mult
  'send ref clock multiplier to the ad9951
  'put multiplier in bits 7..3 of byte
  Ddsrcmtmp = Ddsrcm
  Shift Ddsrcmtmp , Left , 3
  If Ddsclock > Ad9951vcohigh Then
    'set vco bit for high clock speed
    Ddsrcmtmp = Ddsrcmtmp + 4
  End If
  'shift cfrd0 register address out, data on rising edge of clock
  Ddsregaddress = Ad9951cfr2
  Shiftout Ad9951sdio , Ad9951sclk , Ddsregaddress , 1 , 8
  'shift two zero bytes
  Ddsregaddress = 0
  Shiftout Ad9951sdio , Ad9951sclk , Ddsregaddress , 1 , 8
  Shiftout Ad9951sdio , Ad9951sclk , Ddsregaddress , 1 , 8
  Shiftout Ad9951sdio , Ad9951sclk , Ddsrcmtmp , 1 , 8
  'Toggle Ioupdate Pin
  Set Ad9951ioupdate
  Waitus 20
  Reset Ad9951ioupdate
End Sub

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

Sub Progad9951
  'send control byte and four bytes of the tuning word to the ad9951
  'shift ftw0 register address out, data on rising edge of clock
  Ddsregaddress = Ad9951ftw0
  Shiftout Ad9951sdio , Ad9951sclk , Ddsregaddress , 1 , 8
  'shift tuning word out, data on rising edge of clock
  'Ftwlng = &H051EB851
  Shiftout Ad9951sdio , Ad9951sclk , Ftwlng , 1 , 32
  'Toggle Ioupdate Pin
  Set Ad9951ioupdate
  Waitus 20
  Reset Ad9951ioupdate
End Sub

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

Sub Calccftwconstant
  'calculate constant used in tuning word calculation
  'this calculation is rather clumsy because bascom does not have
  'unsigned long and unsigned longlong data types
  'first fill cftw with 2^31 (cannot use 2^32 as the leftmost bit is used
  'as sign bit
  Cftwdbl = Twop31
  'divide this value with current dds clock frequency
  Ddsclockdbl = Ddsclock
  Cftwdbl = Cftwdbl / Ddsclockdbl
  'now the result is small enough to multiply with 2^9 and avoid overflow
  'multiply by 2^9 to get 2^40 (why 2^40 ??? see sub calccftw)
  Cftwdbl = Cftwdbl * Twop9
End Sub

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

Sub Calccftw
  'calculate actual dds frequency tuning word as a four byte integer
  'first, multiply the actaul dds frequency with the constant calculated in Calccftwconstant
  Ddsfrequencydbl = Ddsfrequency
  Ftwdbl = Ddsfrequencydbl * Cftwdbl
  'shift the result right eight bits to correct for the fact that cftw was
  'calculated with effectively 2^40. This value is used so as not to lose
  'accuray in the resulting dds frequency tuning word
  Ftwdbl = Ftwdbl / Twop8
  'store the result in a single. We now lose accuracy!,
  'this is now used instead of a yet to be written procedure to get the correct
  'integer value from a double.
  Ftwsgl = Ftwdbl
  'and get the integer value
  Ftwlng = Int(ftwsgl)
  'Cls
  'Lcd "f" ; Ftwlng
  'Wait 1
End Sub

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

Sub Updddsdisp
  'update lcdisplay
  'display current dds frequency formatted as: xxx,xxx.xxx
  If Multflag = 1 Then
    Cls
    Cursor Off
    Lcd "Multiplier : " ; Ddsrcm
    Locate 2 , 1
    Lcd "Set mult,mnu=nxt"
  Elseif Menuflag = 0 Then
    Tmpddsfreqstr = Str(ddsfrequency)
    Call Calcfreqstr
    Locate 1 , 1
    Lcd Ddsfreqstr ; "MHz  "
    Locate 2 , 1
    Lcd "                "
    If Memdispflag = 1 Then
      Tmpddsfrequency = Eefrequencies(lastmemnum)
      Tmpddsfreqstr = Str(tmpddsfrequency)
      Call Calcfreqstr
      Locate 2 , 1
      Lcd Ddsfreqstr
      Lcd "  M" ; Lastmemnum
    End If
  Else
  'menuflag is set
    Call Calccftwconstant
    Tmpddsfrequency = Ddsclockbasic
    Tmpddsfreqstr = Str(tmpddsfrequency)
    Call Calcfreqstr
    Cls
    Lcd Ddsfreqstr
    Locate 2 , 1
    Lcd "Set clk,mnu=exit"
  End If
  Locate 1 , Blinkposition
  Cursor On , Noblink
End Sub

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

Sub Resetad9951
  'reset ad9951 several times
  For Tmpint = 1 To 5
    Set Ad9951reset
    Waitms 200
    Reset Ad9951reset
  Next Tmpint
End Sub

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

Sub Calcstpexp
  'sub to calculate 10^fstepindex
  Blinkposition = Lookup(ddsfreqstepindex , Fblink)
  Ddsfsexp = Lookup(ddsfreqstepindex , Fsteps)
  Ddsfreqstep = 1
  If Ddsfsexp > 0 Then
    For Tmpint = 1 To Ddsfsexp
    Ddsfreqstep = 10 * Ddsfreqstep
    Next Tmpint
  End If
End Sub

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

Sub Calcfreqstr
'sub to make dds frequency string for display
  Ddsfreqstr = "  0,   .   "
  Strlen = Len(tmpddsfreqstr)
  'Cls
  'Lcd "strlen:" ; " " ; Strlen
  'Wait 2
  Strlen = Strlen - 2
  Tmpstr = Mid(tmpddsfreqstr , Strlen , 3)
  Mid(ddsfreqstr , 9 , 3) = Tmpstr
  Strlen = Strlen - 3
  Tmpstr = Mid(tmpddsfreqstr , Strlen , 3)
  Mid(ddsfreqstr , 5 , 3) = Tmpstr
  Strlen = Strlen - 3
  Tmpint = -2
  If Strlen > -2 Then
    Strlen = Strlen + 2
    Tmpstr = Left(tmpddsfreqstr , Strlen)
    Tmpint = 4 - Strlen
    Mid(ddsfreqstr , Tmpint , Strlen) = Tmpstr
  End If
End Sub

End

'Note: when Fsteps,fblink changes, Fstepsnum constant must be updated accordingly!
'Frequency step values
Fsteps:
Data 0% , 1% , 2% , 3% , 4% , 5% , 6% , 7%
Fblink:
Data 11 , 10 , 9 , 7 , 6 , 5 , 3 , 2 , 1