/* 
 **********************************************************************
 * File  S1deb4.C     -     Rel. 1.1  compile with  uC/51 V. 1.10.10  *
 * GRIFO(R)   via Dell'Artigiano 8/6   40016 S. Giorgio di Piano (BO) *
 * Cards: GPC 554 d.s. 100997 and DEB01 or TIO16                      *
 *     Tel. +39 051 892052                      Fax. +39 051 893661   *
 *     http://www.grifo.com                     http://www.grifo.it   *
 *     sales@grifo.it         tech@grifo.it          grifo@grifo.it   *
 *     by Graziano Gaiba                                   26.09.03   *
 **********************************************************************

 Rel. 1.1 - 26.09.2003 by Graziano Gaiba

 Connect CN5 of GPC(r) 554 to CN15 of DEB01 or CN1 of TIO16 through a
 20 pins+26 pins flat.

 This program shows the status of jumpers J2, J7 and J8 on port A.
*/

#include <reg52.h>
#include <stdio.h>
#include <ctype.h>

// Clock frequency of CPU used
#define FCLOCK              22118400

// On board peripherals registers allocation addresses.
near   unsigned char	    P4	    @ 0xC0;
near   unsigned char	    P5	    @ 0xC4;
static unsigned char  	    RUNDEB  @ 0xFFFF;

	
/********* General purpose utilities and hw sections management ***********/
void iniser(unsigned long baud)
/* Initialise serial port with:		Bit x chr   = 8
					Stop bit    = 1
					Parity	    = None
					Baud rate   = baud
   using timer 1 as baud rate generator.				   */
{
  SCON=0x052;					  // Modo 1, receiver enabled
  TMOD&=0x00F;				       // Timer 1 in auto-reload mode
  TMOD|=0x020;
  TR1=0;						      // Stop TIMER 1
  TH1=256-((2*FCLOCK)/(384*baud));		       // baud at 14.7456 MHz
  PCON=PCON|0x080;			   // Set SMOD=1 for higher baud rate
  TR1=1;						     // Start TIMER 1
}


// Wait for signals settling
void setup(void)
{
  unsigned int i;

  for(i=10000; i!=0; i--)
    ;
}


// Set port A
void setPortA(unsigned char v)
{
  P4=v;
}


// Set port C
void setPortC(unsigned char v)
{
  P1=v;
}


// Get port A
unsigned char getPortA(void)
{
  return P4;
}


// Get port C
unsigned char getPortC(void)
{
  return P1;
}


// Reads status of jumper J2.
// Returns     0x01 if J2 is connected
//             0x00 if J2 is not connected
unsigned char getJ2(void)
{
  return (RUNDEB & 0x80 ? 0x00: 0x01);
}


// Reads status of jumper J7.
// Returns     0x01 if J7 is connected
//             0x00 if J7 is not connected
unsigned char getJ7(void)
{
  return (P5 & 0x80 ? 0x00 : 0x01);
}


// Reads status of jumper J8.
// Returns     0x01 if J8 is connected
//             0x00 if J8 is not connected
unsigned char getJ8(void)
{
  return (P5 & 0x40 ? 0x00 : 0x01);
}


// Delay to prevent serial line overrun
void ritardo(void)
{
  unsigned int i;

  for(i=0xffff; i!=0; i--)
    ;
}


// **************************** Main program *****************************

void main(void)
{
  unsigned char r;

  setup();                         // Wait for signals settling

  iniser(19200);
  TI=0;
  RI=0;

  // Comment next two lines if serial port is used in polling (SIOTYPE=p or k)
  ES=1;                                 // Enable serial port interrupt
  EA=1;					// Enable all interrupts


  puts("********************* Demo S1DEB4  **********************");
  puts("");
  puts("Shows status of jumpers J2, J7 and J8 respectively in the first 3 bits");
  puts("of PORT A.");

  for (;;)		           // Infinite loop.
  {
    r=0xFF;
    if(getJ2())
    {
      r&=~0x01;                    // J2 connected
    }

    if(getJ7())
    {
      r&=~0x02;                    // J7 connected
    }

    if(getJ8())
    {
      r&=~0x04;                    // J8 connected
    }

    setPortA(r);
  }			  			  	 
}