$regfile = "2313def.dat"
$crystal = 4000000

Config Sda = Portd.5
Config Scl = Portd.4
Config I2cdelay = 10
Config Pind.6 = Output

Const Jcl1562bwrite = &H70
Const Jcl1562bread = &H71
'mask out all but the lower six dac bits
Const Jcl1562bcompon = &B11000000
'make this pin high to use it as input
Const Jclmask = &B00000001

Dim Dacval As Byte
Dim Dacwrite As Byte
Dim Jclinput As Byte

Cls
Do
  Reset Portd.6
  For Dacval = 0 To 63 Step 1
    Dacwrite = Dacval Or Jcl1562bcompon
    I2cstart
    I2cwbyte Jcl1562bwrite
    I2cwbyte Jclmask
    I2cwbyte Dacwrite
    I2cstop
    I2cstart
    I2cwbyte Jcl1562bread
    I2crbyte Jclinput , Nack
    I2cstop
    Jclinput = Jclinput And Jclmask
    If Jclinput = Jclmask Then
      Exit For
    End If
  Next Dacval
  Locate 1 , 1
  Lcd Dacval ; "    "
Loop

End