' **********************************************************************
' ** Program : gmbsere.bas    -    Version :   1.1   -   24 June 2003 **
' ** Compiler : BASCOM 8051 DEMO, (IDE and LIB V.2.0.11.0)            **
' ** Board : GMB HR84 with CAN GMx or GMM yyyy                        **
' ** 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                                      **
' **********************************************************************
'
' This demo is a simple example of communication capableto work with all
' electric protocols available on CN2 (RS 232, RS 422, RS 485, current loop or
' TTL).
' In detail, through high level functions, it is possible to program baud rate
' from console, then each character received from serial port is sent to the
' port itself; reception of character 'r' decides how to manage the
' communication direction (signal DIR) for RS 422 and RS 485.
'
' 24.06.03 - Rel 1.1 By Graziano Gaiba
'
'   The file compiled is smaller than 2048 bytes, so it can be compiled
'   with free demo version of BASCOM 8051.
'
'****************** Compiler directives **************************
'
' Set to 80h internal memory limit by:
' Options/Compiler/Misc
$regfile = "grifo_mm.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

' Board where the demo is running
Const Can_gm1 = "1"
Const Can_gm2 = "2"
Const Gmm_5115 = "3"

Const Attivo = 1                          ' Value to activate driver 422 or 485
Const Disattivo = 0                       ' Value to deactivate driver 422 or 485

Tia Alias Scon.1                          ' Transmission flag for serial A
Ria Alias Scon.0                          ' Reception flag for serial A
'
'****************** Variables declaration **********************
'
' Generic use
Dim S1 As String * 1                      ' Generic input
Dim V1bit As Bit                          ' Transmission driver status

' Used by low level procedures
Dim Char As Byte
Dim Rate As Long                          ' Baud rate required by the user
Dim Valore As Byte                        ' Timer value for baud rate

' Board where the demo is running
Dim Board As Byte
'
'********************* Procedures declaration *************************
'
Declare Sub Ser_a                         ' Programming serial line A
Declare Sub Txa(char As Byte)             ' Manages transmission on serial line A
Declare Sub Rxa                           ' Manages reception on serial line A
'
'************************** Main program ******************************
'
Main:
' Inizializes demo
   Disable Interrupts                     ' Disabiles interrupts
   Auxr = &H0C                            ' Selects Eram on external data area
   Eecon = &H00                           ' Disables Eeprom of Micro
   Adcf = &H00                            ' Port 1 as I/O
   P3 = &HFF                              ' Sets port 3 as input

Do
   Print Chr(clrscr);                     ' Clear screen
   Print "Demo 1.1 for GMB HR84  ds 100203"
   Print
   Print "Which Mini Modulo grifo(r) is the demo running on:"
   Print "1) GM1"
   Print "2) GM2 or 5115"
   Print
   Print "SELECT: ";
   Do
      Board = Inkey                       ' Stand by a key
   Loop Until Board <> 0

   Print Chr(board)
   ' UART management in RS 232 and TTL
   Print
   Print "In RS 232: set ON switches 2 and 3, set OFF switches 4 and 5 of DSW1"
   Print "Software management is made by Bascom,see documentation for more info"
   Print "Set OFF switches 2 and 3, set ON switches 4 and 5, to have UART TTL signals"
   Print "directly to the socket pins."
   Print
   Print "Press a key to continue..."
   S1 = Waitkey
   Print
   Print "Connect J7 in ";
   If Board = Can_gm1 Then                ' Correct connection of DIR
      Print "1-2"
   Else
      Print "2-3"
   End If
   ' Low level communication because BASCOM
   ' does not manage direction with high level instructions
   Input "Baud rate:" , Rate
   ' Value = 256 -((14745600) /(384 * BaudRate))
   Rate = 384 * Rate
   Valore = 14745600 / Rate
   Valore = 256 - Valore
   Call Ser_a
   Print "Test in RS232, then configure GMB for other protocol:"
   Print "turn off power supply, set DSW1:"
   Print "2=3=OFF,4=5=ON, then:"
   Print
   Print "RS422:"
   Print "-install SN75176 or MAX483 on IC1 and IC2"
   Print "-J2=1-2 J3=1-2 J4=1-2 J5=2-3"
   Print
   Print "RS485:"
   Print "-install SN75176 or MAX483 on IC1"
   Print "-J2=1-2 J3=1-2 J4=1-2 J5=1-2"
   Print
   Print "If at net termination->J1 connected"
   Print "R switches transmitter"

   V1bit = Disattivo                      ' memorize status
   If Board = Can_gm1 Then
      P2.3 = 1                            ' Set as output
   Else
      P1.3 = 1                            ' Set as output
   End If

   Do
      Call Rxa                            ' Receive from serial line A
      If Char <> 0 Then                   ' Character available on serial line A
         Call Txa(char)                   ' Send character to serial line A
         Char = Char Or &H20              ' Convert to lower case
         If Char = "r" Then
            If V1bit = Attivo Then        ' If it was off
               If Board = Can_gm1 Then
                  P2.3 = 1
               Else
                  P1.3 = 1                ' enable transmission
                                          ' of driver 422 or 485
               End If
               V1bit = Disattivo
            Else                          ' viceversa
               If Board = Can_gm1 Then
                  P2.3 = 0
               Else
                  P1.3 = 0                ' disable transmission
                                          ' del driver 422 o 485
               End If
               V1bit = Attivo
            End If
         End If
      End If
   Loop
End
'
'************************ Program end ***************************
'
'
'**************************** Procedures ********************************
'
'
' **************** Manages transmission on serial line A ***********************
' * This procedure allows to send on character to serial line A, character to  *
' * send in variable char                                                      *
' ******************************************************************************
'
Sub Txa(char As Byte)                     ' Gestisce la trasmissione sulla seriale A
   Bitwait Tia , Set                      ' Wait for previous character sent
   Tia = 0                                ' reset transmision bit
   Sbuf = Char                            ' Send character
End Sub
'
' ***************** Manages reception from serial line A ***********************
' * This procedure returns the character received from serial line A,stores it *
' * in variable valore, if no char received returns 0 in variable char.        *
' ******************************************************************************
'
'
Sub Rxa                                   ' Manages reception on serial line A
   If Ria = 1 Then
      Ria = 0                             ' Reset reception bit
      Char = Sbuf                         ' Read received character
   Else
      Char = 0                            ' No character received
   End If
End Sub


' Initialization baud rate generators
Sub Ser_a
   Tcon = 0
   Scon = &B01010010                      '01010010
                                          '||||||||__ RI must be initialized 0
                                          '|||||||___ TI must be initialized 1
                                          '||||||____ Not important in this case
                                          '|||||_____ Not important in this case
                                          '||||______ Enable reception flag
                                          '|||_______ Disables multiprocesor
                                          '||________
                                          '|________> 8 bits UART
'
   Tmod = &B00100011                      '00100011
                                          '||||||||__
                                          '|||||||__> T0 8 bits timer/counter with autoreload
                                          '||||||____ T0 as Timer.
                                          '|||||_____ T0 off
                                          '||||______
                                          '|||______> T1 8 bits timer/counter with autoreload
                                          '||________ T1 as timer
                                          '|_________ T1 off
'
   Pcon = &B00000000                      '00000000 MSB in PCON must be 0
                                          '|
                                          '|
                                          '|________Smod, If= 1, doubles Baud Rate
                                          '               set on serial line A
'
   Th1 = Valore                           ' Baud rate decided by the user
   Set Tcon.6                             ' T1 on, start timer1, enable communication on A
End Sub