' **********************************************************************
' ** Program : gmbsere.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                      **
' **                                                                  **
' ** Written by:  Graziano Gaiba                       02.02.2005     **
' **********************************************************************
'
' This demo is a simple example of communication capableto work with all
' electric protocols available on CN6 (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.
'
' 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


Tia Alias Scon.1                          ' flag of transmission happened on serial A
Ria Alias Scon.0                          ' flag of reception happened on serial A
'
'
'****************** Constants declaration ***********************
'
Const Cret = 13                           ' Carriage return
Const Nl = 10                             ' New line
Const Clrscr = 12                         ' Clear screen
Const Bell = 7                            ' Bell

Const Attivo = 1                          ' Value to enable driver 422 or 485
Const Disattivo = 0                       ' Value to disable driver 422 or 485
'
'
'*********************** Variables declaration *************************
'
' Generic use
Dim S1 As String * 1                      ' One character strings
Dim S0 As Bit                             ' Generic use bit
Dim S As Byte

' Used by serial demo
Dim Bitrate As Long
'
'
'****************** Procedures declaration **********************
'
Declare Sub Ser_a                         ' Setting serial line A
Declare Sub Txa(s As Byte)                ' Manages transmission on serial line A
Declare Sub Rxa                           ' Manages reception on serial line A
'
'**************************** Main program *********************************
'
Main:

   Disable Interrupts                     ' Disables interrupts
   Auxr = &H0C                            ' Selects Eram on external data area
   Eecon = &H00                           ' Disables write to micro Eeprom
   Call Setp01234input()

   Print Chr(clrscr)                      ' Clears screen
   Print "Demo 1.2 for Module GMB HR168 d.s. 110104"
   Print
   ' 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 J6, J7 e J8 in 2-3"
   ' We use low level communication because BASCOM
   ' does not manage communication direction with high level instructions
   Input "Baud rate:" , Bitrate
   ' Valore = 256 -((2*14745600) /(384 * BaudRate)) or
   ' Valore = 256 -((14745600) /(384 * BaudRate)) according to CKCON for UART
   Bitrate = 384 * Bitrate
   S = 14745600 / Bitrate
   S = 256 - S
   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 IC10 and IC11"
   Print "-J5=2-3 J6,J7,J8=1-2 J10=1-2"
   Print
   Print "RS485:"
   Print "-install SN75176 or MAX483 on IC10"
   Print "-J5=1-2 J6,J7,J8=1-2 J10=1-2"
   Print
   Print "If at net termination, J3 and J4 must be connected"
   Print "R switches transmitter"

   S0 = Disattivo                         ' memorize status
   P2.3 = 1                               ' Set as output
   Do
      Call Rxa                            ' Receive from serial line A
      If S <> 0 Then                      ' Character available on serial line A
         Call Txa(s)                      ' Send character to serial line A
         S = S Or &H20                    ' Convert to lower case
         If S = "r" Then
            If S0 = Attivo Then           ' If it was off
               P2.3 = 1                   ' enable transmission
                                          ' of driver 422 or 485
               S0 = Disattivo
            Else                          ' viceversa
               P2.3 = 0                   ' disable transmission
                                          ' of driver 422 or 485
               S0 = 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(s As Byte)                        ' Gestisce la trasmissione sulla seriale A
   Bitwait Tia , Set                      ' Wait for previous character sent
   Tia = 0                                ' reset transmision bit
   Sbuf = S                               ' 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
      S = Sbuf                            ' Read received character
   Else
      S = 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 = S                                ' Baud rate decided by the user
   Set Tcon.6                             ' T1 on, start timer1, enable communication on A
End Sub
'
'
' Set all ports as input
'
Sub Setp01234input()
   P0 = &HFF                              ' Set P0 as input
   S = P0
   Adcf = &H00                            ' Set P1 as I/O
   P1 = &HFF                              ' Set P1 as input
   S = P1
   P2 = &HFF                              ' Set P2 as input
   S = P2
   P3 = &HFF                              ' Set P3 as input
   S = P3
   P4 = &HFF                              ' Set P4 as input
   S = P4
End Sub