n_fill.c

PIC_Hi-Tech_C_Mike_Pearces_12C509_logic_gate_replacement源码

//***************************************************************************
//                               N_Fill.c
//
//                             Version 1.00
//
// Software to replace logic driving the Liquid Nitrogen Filler system
// Uses PIC12C508 - 3 inputs, 1 output, 15 minute timeout.
//
// Author: Michael Pearce
//         Chemistry Department, University of Canterbury.
//
// Started: 30 November 1998
//
//***************************************************************************
#include <pic.h>

#define  XTAL_FREQ 4MHZ
#include "delay.h"
#include "delay.c"

#define  TIMEOUT  8         //-- Minutes to timeout
#define  MAXTIME  (TIMEOUT * 60 * 1000000)/256    //-- us divided by 256
#define  SECOND   (1000000/256)                  //-- counts per second
#define  OFF 1              //-- OFF State of output
#define  ON  0              //-- ON  State of output
#define  TIMEOUT_ON  1      //-- ON State for Timeout LED
#define  TIMEOUT_OFF 0      //-- OFF State for Timeout LED

#define  TRUE  1
#define  FALSE 0



#define BITNUM(adr, bit)       ((unsigned)(&adr)*8+(bit))
static bit  DEAD       @ BITNUM(GPIO, 0);  //- Dangerously LOW
static bit  EMPTY      @ BITNUM(GPIO, 1);  //- Lower Limit
static bit  FULL       @ BITNUM(GPIO, 2);  //- Upper Limit
static bit  OUTPUT     @ BITNUM(GPIO, 4);  //- Output Control Pin
static bit  TIMEOUTPIN @ BITNUM(GPIO, 5);  //- Timeout Indicator.

unsigned long Counter;
bit CountEnabled;
bit Filling;
bit TMRHIGH;

void Error(char Type);


//***************************************************************
//main
//***************************************************************
void main (void)
{
 char HourNotUp=0,Minute,Second;

 OPTION=0xD8;              //- 11011000  Set upt the option Register

 GPIO=0xFF;                //-- All Outputs HIGH
 TIMEOUTPIN=TIMEOUT_OFF;   //-- No Timeout yet so turn LED OFF
 OUTPUT=OFF;               //-- Don't Fill so Output is OFF
 TRIS=0x0F;                //-- Set Up 0 to 3 as input rest as output

 CountEnabled=0;
 Counter=0;
 Filling=0;
 TMRHIGH=0;


 while(1)
 {
  //********************* Check the Timeout *********************
  if(CountEnabled)
  {
  	if(TMR0 >0x80 && TMRHIGH==0)   //-- If TMR0 > 0x80 then dec counter once
  	{
    TMRHIGH=1;                 //-- set flag so multi decrement does not happen
	 Counter++;                 //-- increment the counter
	 if(Counter > MAXTIME)      //-- Check for Timeout rollaround
	 {
	  //-- Halt the system cause ya just timed out!!!!
	  //-- After a 1 hour wait - give it another go.
	  Counter=0;   //-- Reset Outside counter to restart after the hour.
	  HourNotUp=1;
	  Minute=0;
	  Second=0;
	  while(HourNotUp)
	  {
	  	OUTPUT=OFF;                //-- Disable the filler
	  	TIMEOUTPIN=TIMEOUT_ON;     //-- Indicate a timeout occured
	  	DelayMs(250);              //-- Flash the LED at 1 Hz
	  	DelayMs(250);
	  	TIMEOUTPIN=TIMEOUT_OFF;    //-- with a 50% duty Cycle
	  	DelayMs(250);
	  	DelayMs(250);
	  	if(++Second>=60)           //-- Done a Minute?
	  	{
	    Second=0;                 //-- reset for next count.
       if(++Minute>=60)          //-- Done an Hour??
       {
        HourNotUp=0;             //-- Times Up - so restart
       }
	  	}
	  }
	  //-- RESTART HERE
     CountEnabled=0;
     Counter=0;
	  Filling=0;
	  TMRHIGH=0;
     TIMEOUTPIN=TIMEOUT_OFF;   //-- No Timeout yet so turn LED OFF
     OUTPUT=OFF;               //-- Don't Fill so Output is OFF
	 }
	}
	else
	{
	 //-- enable the next increment of the timeout counter
	 if(TMR0 <0x80) TMRHIGH=0;
   }
  }
  //******************* Check the Pin Status *********************

  //***** Above FULL? *****
  if(FULL)
  {
  	OUTPUT=OFF;              //-- Disable the Filler
  	TIMEOUTPIN=TIMEOUT_OFF;  //-- Disable Timeout/Error Indicator
  	CountEnabled=FALSE;      //-- Disable the Timeout Counter
  	Counter=0;               //-- Reset the Counter
  	if(!EMPTY)
  	{
    //-- If FULL but indicating Empty then a SENSOR error occured
	 Error(1);
   }
  }
  else
  {
   //***** Below Empty? *****
   if(!EMPTY)
   {
    OUTPUT=ON;
	 CountEnabled=TRUE;
   }
  }
  //-- Ignore this pin - no longer required to be monitored.
  //if(!DEAD)
  //{
	//-- Something Badly Wrong - Keep Trying to fill until TimeOut Occurs
   //Error(2);
  //}
 }
}
//***************** END OF main

//***************************************************************
//Error - Flashes the Timeout LED in different Pattern to usual
//***************************************************************
void Error(char Type)
{
 Type++;
 for(;Type>0;Type--)
 {
  TIMEOUTPIN=TIMEOUT_ON;
  DelayMs(100);
  TIMEOUTPIN=TIMEOUT_OFF;
  DelayMs(200);
 }
 DelayMs(250);
 DelayMs(250);
 if(CountEnabled==1)
 {
  Counter-=(SECOND);
 }
}
//********** END OF Error