Virtual Integrated Design, RS232 relay circuit

Relay Circuit

RS232 relay driver

RS232 relay controller

File 1:

#pragma option +v

// relay.c
// 03/04/2000
// (C) Virtual Integrated Design

#include <16c54.h>
#include <rx12.c>
#include <tx12.c>
#include <delay12.h>

#define address 0x01

void xmit_19200_4mhz(unsigned char);
unsigned char receive_19200_4mhz(void);

unsigned char x @0x0F;
unsigned char y @0x10;

void main(void)
{

__TRIS(0x1,PORTA); // 0=input 1,2,3=outputs
__TRIS(0x00,PORTB); // all output
NOP();
PORTA=0XB;
PORTB=0x00;

while(1)
{

x=receive_19200_4mhz();

if(x==address)
{
    y=receive_19200_4mhz();
    PORTB=y;
    xmit_19200_4mhz(x);
    xmit_19200_4mhz(y);
    PORTA.3=0; // led on
}
else
{
   PORTA.3=1; // led off
}

}

}
//------------------------------------------------------
#include <delay12.lib>

File 2:

#pragma option +v

// rx12.c
// 03/04/2000
// (C) Virtual Integrated Design

#include <16c54.h>
#include <delay12.h>

unsigned char receive_19200_4mhz(void)
{
unsigned char i, x=0;

// Start Bit
while(PORTA.0);
PORTA.2=1; // debug
Delay_10xUs_4MHz(7);
PORTA.2=0; // debug
NOP();
NOP();

// Bits 1-7
for(i=0;i<7;i++)
{
PORTA.2=1; // debug
   if(PORTA.0)
   {
    x|=0x80;
   }
   else
   {
    x|=0x01;
    NOP();
   }
   x=x>>1;
   Delay_10xUs_4MHz(3);
PORTA.2=0; // debug
}

PORTA.2=1; // debug

// Bit 8
if(PORTA.0)
{
x|=0x80;
}
Delay_10xUs_4MHz(5);

PORTA.2=0; // debug

return x;
}
/*-----------------------------------*/
#include <delay12.lib>

File 3:

#pragma option +v

// tx12.c
// 03/04/2000
// (C) Virtual Integrated Design

#include <16c54.h>
#include <delay12.h>

void xmit_19200_4mhz(unsigned char t)
{
unsigned char i;

// Start Bit
PORTA.1=0;
Delay_10xUs_4MHz(3);

for(i=0;i<8;i++)
{
t=t>>1;
if(STATUS.C)
{
   PORTA.1=1;
}
else
{
   PORTA.1=0;
   NOP();
   NOP();
   NOP();
}
Delay_10xUs_4MHz(3);
NOP();
NOP();
}

// Stop Bit
NOP();
NOP();
NOP();
PORTA.1=1;
Delay_10xUs_4MHz(4);

}
/*-----------------------------------*/
#include <delay12.lib>

Hex File:

:020000040000FA
:08000000520A6A000506020A1B
:080008004505070C260945041B
:08001000000000006900070C6C
:08001800890003061D0A4505DD
:080020000507140AEA05160A9F
:080028000A05000003042A038D
:08003000030C26094504A90296
:080038000B0A45050506EA0567
:08004000050C260945040A0223
:0800480027000008000027005A
:080050000000000000000000A8
:08005800000000000000E702B7
:08006000280A00082B0025040A
:08006800030C26096C00080CD2
:080070008C0003064B0A030497
:080078002B030307410A2505D3
:08008000450A25040000000000
:080088000000030C2609000032
:080090000000AC02370A000079
:08009800000000002505040C26
:0800A00026090008010C05000F
:0800A800000C060000000B0C27
:0800B0002500660001090702AA
:0800B8002F00010C8F0043072B
:0800C0006B0A01090702300080
:0800C80026000F0232091002AC
:0800D000320965046C0A6505A4
:0400D8005A0A0008B8
:0203FE0063009A
:00000001FF