' **********************************************************************
' ** Program : gmbdae.bas   -    Version :   1.2                      **
' ** Compiler : BASCOM 8051 DEMO, (IDE and LIB V.2.0.11.0)            **
' ** Board : GMB HR168 with GMM ACZero                                **
' ** Corporate:   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                      **
' ** sales@grifo.it          tech@grifo.it          grifo@grifo.it    **
' **                                                                  **
' ** Written by:  Graziano Gaiba                          02.02.2005  **
' **********************************************************************
'
' This demo uses section 0 of Mini Module PCA to generate, on CN7, a PWM signal
' with preset frequency and duty cycle programmable in percent by console.
' Such signal, connected to an opportune intergrating circuit (RC network,
' operational amplifire with capacitor on feedback, etc.) allows to obtain an
' anlog signal like the one of a D/A. Demo execution depends on which Mini
' Module is used and serial line configuration.
'
'
' Rel. 1.1   03.03.04 - By Graziano Gaiba
'
' Rel. 1.2   02.02.05 - By Graziano Gaiba
'
' Modified to work with GMM ACZero
'
'
' !!!!!!!!!!!!!!!!!!!!!!! ATTENTION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
' In menu Options/Compiler/Misc set:
' - Byte End(hex) at least A0
'
'
'   The file compiled is smaller than 2048 bytes, so it can be compiled
'   with free demo version of BASCOM 8051.
'
'
'****************** Compiler directives **************************
'
$regfile = "8951cc03.dat"
$romstart = &H0                           ' start address of code for FLASH
$ramstart = &H0                           ' start address of external RAM
$ramsize = &H100                          ' 256 bytes of external RAM
$crystal = 14745600                       ' Microcontroller clock
$baud = 19200                             ' RS-232 baud rate
'$large                                   ' 16 bit addressing for jumps
                                          ' (Not for demo version)
$map                                      ' Generates address map
'
'
'****************** Constants declatation ***********************
'
Const Cret = 13                           ' Carriage return
Const Nl = 10                             ' New line
Const Clrscr = 12                         ' Clear screen
Const Bell = 7                            ' Bell

Cr Alias Ccon.6                           ' PCA timer control
'
'
'****************** Variables declaration **********************
'

' Generic use
Dim S As Byte , C As Byte                 ' Generico use and SetPwm
Dim S1 As String * 1
'
'
'************************** Main program ******************************
'
Main:

' Inizializes demo
Disable Interrupts                        ' Disabiles interrupts
Auxr = &H0C                               ' Selects Eram on external data area
Eecon = &H00                              ' Disables Eeprom of Micro
P3 = &HFF                                 ' Sets port 3 as input

Do
   Print Chr(clrscr);                     ' Clear screen
   Print "Demo 1.2 for GMB HR168  ds 110104"
   Print
   Print "Is the GMB HR168 in RS 422 or 485 (Y/N)? ";
   Do
      S1 = Waitkey
      S1 = Ucase(s1)
   Loop Until S1 = "Y" Or S1 = "N"
   Print S1
   If S1 = "Y" Then
      Print "Pin 6 of CN4 may be used for communication direction."
      Print "PWM for D/A not available."
      Do
      Loop
   End If

' Management of PCA capture/compare modules as PWM generators
   Print
   Print "Demo of PCA as PWM on pin 6 of GMB HR168 CN7"
   Print
   Print "Pin 6 of CN7 can generate a PWM signal that can become an analog signal"
   Print "(D/A) by a simple integrator (RC network, op. amp. with capacitor on"
   Print "feedback circuit, etc). PWM resolution is 8 bit while frequency can be"
   Print "set by software."
   Print "This demo allows to program duty cicle and uses a frequecy=Fclk/(2*6*256)KHz."

   C = Adcf
   C.3 = 0
   Adcf = C                               ' P1.3 as I/O
   Cmod = &H00                            ' Clock frequency is
                                    ' FPca divide by 6, peripheral enabled to
                                    ' work also in Idle Mode, no interrupt
   Cr = 1                                 ' Enable PCA Timer/Counter
   Do
      Print
      Do
         Input "Duty Cycle (0..100 %): " , S
      Loop Until S >= 0 And S <= 100
      S = S * 2.55
      Ccapm0 = &H42                       ' Enable PWM on module 0 PCA
      Ccap0h = S                          ' Activate PWM output
      Print "Setting performed."
   Loop
   Cr = 0                                 ' Stops PCA Timer/Counter
End
'
'
'************************ Program end ***************************
'