' **********************************************************************
' ** Program: gmbdae.BAS    -    Version : 1.1   -   29 January 2004  **
' ** Compiler : Bascom AVR IDE - LIB 1.11.7.4                         **
' ** Scheda : GMB HR84 and GMM AM08                                   **
' ** 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                      **
' ** sales@grifo.it          tech@grifo.it          grifo@grifo.it    **
' **                                                                  **
' ** Written by:  Graziano Gaiba                                      **
' **********************************************************************
'
' Rel. 1.1   29.01.04 - By Graziano Gaiba
'
' This demo uses Timer 2 of Mini Module to generate, on CN4, 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.
'
'   Compiled file is smaller than 2048 bytes, so it can becompliled with free
'   demo of BASCOM AVR.
'
'
' !!!!!!!!!!!!!!!!!!!!!!!!!!! IMPORTANT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
' In menu Options | Compiler | Chip, set:
'
' Chip:       M8
' HW Stack:   at least 64
' Soft Stack: at least 32
' Framesize:  at least 64
'
'
$regfile = "m8def.dat"
$crystal = 7372800
$baud = 19200
'
' ********************* Constans declarations *************************
'
Const Cret = 13                                             ' Codice di ritorno di carrello
Const Nl = 10                                               ' Codice nuova linea
Const Clrscr = 12                                           ' codice di clear screen
Const Bell = 7                                              ' codice di Bell
'
'****************** Variables declaration **********************
'
' Generic use
Dim S As Byte                                               ' Generic use and SetPwm
Dim S1 As String * 1
'
'****************** Procedures declartion **********************
'
Declare Sub Init()                                          ' Initialization
Declare Function Leggi_char() As Byte                       ' Read one character (blocking)
'
'************************** Main program ******************************
'
Main:

Do
   Call Init()
   Print "PWM demo"
   Print
   Print "Timer 2 (8 bit) is configured as PWM (pin 8 of socket)."
   Do
      Inputhex "Duty cycle in hex (E.g. 0F): " , S
      Ocr2 = S                                              ' Set duty cycle
      Print "F to exit or any other key to re-set duty cycle"
      S = Leggi_char()
   Loop Until S = "F"
   Tccr2 = &H48                                             ' Stop Timer 2
Loop
End
'
' *************************** Program end ******************************
'
'
' **************************** Procedures ******************************
'
'
' Initialize demo
'
Sub Init()
   Ddrb = Ddrb Or &H08                                      ' Set portb.3 as output
   Ocr2 = &H80                                              ' Duty Cycle 50%
   ' Timer 2 configured for Fast PWM, No Prescaler, Sets to 1 pin 8 of socket
   ' on every match between register OCR2 and counter register of Timer 2
   Tccr2 = &H79
   Tcnt2 = 0                                                ' Reset timer
End Sub
'
'
' Reads a character in blocking way,converts it in capital letter and prints it
'
Function Leggi_char() As Byte

   Local C As Byte

   C = Waitkey()
   Print Chr(c)
   C = C And &HDF                                           ' Converts ASCII character in capital letter

   Leggi_char = C
End Function