UV Dental timer

/*Using the Boost C Compiler for pic micro  MD Harrington purchased from Maplin electronics now closed
8 years ago before people changed for the worse I was doing this
A dental  UV tooth whitener I built for someone in an urgent hurry  so they could hang on to a job

They might not remember I do though */


/* You can find the full code  on my git hub account plus schematics parts list , PCB outlay and hex code
https://github.com/markh2016/UV_Dental_Timer

https://www.facebook.com/mark.harrington.14289/



*/



#include <system.h>
// DATA CONFIGURATION FOR 12F675
#ifndef _PIC12F675
#error "This sample code was designed for PIC12F675"
#pragma DATA_CONFIG, _CPD_OFF & _CP_OFF  & _WDT_OFF & _BODEN_OFF & _PWRTE_OFF  & _MCLRE_OFF & _INTRC_OSC_NOCLKOUT
#endif //_PIC12F675
// CONFIG FOR OSCAL 344C
// GLOBAL VARIABLES
/* These are the Interrupts and flags for later use
GIE Global interrupt enable
PIE Peripheral interrupt enable
INTF Interrupt Flag must be cleared after interrupt
TOIE                Timer interrupt enable
TIOF                Timer interrupt Overflow Flag
GPIE                general purpose interrupt enable
GPIF  general purpose interrupt flag
*/
#define  CLEAR  0x00 ;
#define  Pressed  0 ;      // this is bit 0 of our Flags register
#define     State    1 ;   // this  is bit 1 of our Flags Register
#define     TimerState 2 ;    // this is bit 2 of ourFlags register
unsigned swVal = 0 ;
unsigned char  curState ;
unsigned char  timer    ;
unsigned char seconds ;       // stores and increments seconds
unsigned char minutes ;       // stores and increments minutes
unsigned char milliseconds ;  // stores and  increments the milliseconds
unsigned char TMRFlag  ;      /* stores the status of the timer
   when timer is activated for light is Zero
   for final minute countdown this is 1 */
unsigned char max_seconds ;   /* For storing the maximum seconds
  when light is on this 9 when final minute
  this is equals  1 */
unsigned char tmrOffset ;
unsigned char oldseconds = 0x00 ;
// method forward declaration
void startTimerLight(unsigned char maxMinutes);
void init(void) ;
void sound(unsigned char period , unsigned char cycles, unsigned char duration) ;
unsigned char startTimer(unsigned char maxvalue) ;
unsigned char  getKeyPress(void) ;
void notifyFinish(unsigned char lastSecs , unsigned char secsInterrupt) ;
/*
 personal notes for PCB Layout this may differ
 from time to time
 Soundport gpio.2 ;
    button    gpio.0 ;
    Luxion    gpio.1 ;
*/
void interrupt(void)
{
 // HANDLES  TIMER INTERRUPT
 // disable GIE
clear_bit(intcon, T0IE);            // Disable Timer 0 Interrupts
clear_bit(intcon, GIE);             // clear Global interrupt
 if(TMRFlag == 0x00)
 {
 startTimerLight(9) ;
 }
clear_bit(intcon, T0IF);
  if((timer == 1)&&(TMRFlag == 0x00))
 {
  set_bit(intcon,GIE) ;
  set_bit(intcon, T0IE);
 }
 if ((TMRFlag == 0x01)&&(timer ==0))
 {
  set_bit(intcon,GIE) ;
  set_bit(intcon, T0IE);
   // final minute call notify
   notifyFinish(60,1);
 }
}
// 12F675 register settings
       /* | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
          NU   NU  out in  nu  out out  in
          0    0   0    1   0   0    0   1
 =  0x11 hex
  */
void init(void)
{
    vrcon = CLEAR;                    // Turn off the voltage reference peripheral
    cmcon = 0b00000111;              // Disble comparator module - make Port  digital I/O port
    ansel = CLEAR;                    // For the 12F675 Only
    gpio = CLEAR;                    // Clear the output ports
 trisio = 0x11  ;                 // set up port direction
    wpu = 0b00000000;                // En/disable Weak Pull Ups
 /* T1CON — TIMER1 CONTROL REGISTER (ADDRESS: 10h)
          7
          6   Gate enable bit sued for external triggering
       5   T1CKPS1: Next two bits are the pre scale bits
          4   T1CKPS0
   3   T1OSCEN: LP Oscillator Enable Control bit If INTOSC without CLKOUT oscillator is active:
   2   T1SYNC: Timer1 External Clock Input Synchronization Control bit
   1   TMR1CS: Timer1 Clock Source Select bit
          0   TMR1ON: Timer1 On bit setting enables timer
    */
   // clear all registers
    seconds = CLEAR ;
    minutes = CLEAR ;
    milliseconds = CLEAR ;
    TMRFlag = CLEAR ;
    max_seconds = CLEAR ;
    tmrOffset = CLEAR  ;
    oldseconds = CLEAR ;
    timer = 0x00 ;
 // Enable/disbale interrupts
    clear_bit(intcon, T0IE);            // Disable Timer 0 Interrupts
    clear_bit(intcon, GIE);             // Disable Global Interrupts
    clear_bit(intcon, T0IF);
 delay_us(100) ; // allow time for cpu to settle
}
void sound(unsigned char period , unsigned char cycles, unsigned char duration)
{
 for(int j = 0 ; j < duration; j++ )
 {
 for(int i = 0 ; i < cycles; i ++)
 {
 delay_us(period);
 {
  toggle_bit(gpio,2) ;
 }
 }
 }
 gpio.2 = 0 ; // switch off luxian
}
/*Notes A simpler way to access a bit within a byte is to use a constant expression of the form
 (1 << n)
where n is the bit number and << is the left shift operator
*/
// starts the TMR0 interrupt loads timer with value and
// begins light time on sequence
unsigned char startTimer(unsigned char maxvalue)
{
    tmr0 = CLEAR ;
   // GPPU INTEDG T0CS T0SE PSA PS2 PS1 PS0
 //   0    0     0     0   0   1    1  1
    option_reg = 0x07 ; // use  256 pre scaling
    // enable interrupts and timer interrupt
    // clear overflow flag to start with
    clear_bit(intcon, T0IF);
    set_bit(intcon, GIE);             // enable Global Interrupts
    tmr0 = maxvalue ;
 set_bit(intcon, T0IE);            // enable Timer 0 Interrupts
    return 0x01 ;
}
unsigned char getKeyPress(void)
{
        unsigned char  value = 0x00 ;
     while(value == 0x00)
 {
     value = gpio.0 ; // get the value
 delay_us(255);
 }
 value = (0x11 & value) ;  // masking to ensure we have correct bits for input
     return value  ;
}
void startTimerLight(unsigned char maxMinutes)
{
milliseconds += 1 ; // increment milliseconds by one
            if(milliseconds == 60)
 { milliseconds  = 0 ; // reset milliseconds
 seconds +=1 ;  // increment seconds by one
 if(seconds == 60)
 {
  seconds = 0 ;
  minutes += 1 ;
   if(minutes == maxMinutes)
   {
 minutes = 0 ;
     TMRFlag = 0x01 ;
 timer = 0 ;
   }// end if minutes
 }// end if seconds
 }// end if milliseconds
 tmr0 = CLEAR ;
 tmr0 = tmrOffset ;
}
void notifyFinish(unsigned char lastSecs , unsigned char secsInterrupt)
{
  milliseconds +=1 ;
     if(milliseconds == 60)
     {
 milliseconds  = 0 ; // reset milliseconds
 seconds +=1 ;  // increment seconds by one
 oldseconds+=1 ;
 if(oldseconds == secsInterrupt)
 {
   // sound alarm for finishing
   sound(200,200,5);  // makes a beep noise for number of reps
   oldseconds = 0 ;
 }
 if(seconds == lastSecs)
 {
 seconds = 0;
                    timer = 0 ; // we have finshed back to key press
 TMRFlag = 0x00 ; // reset this flag to notify back into timer state
 gpio.1 = 0 ; // switch off led
 gpio = CLEAR ;
 // finally disable intrerrupts again
  // disable intterupt
     clear_bit(intcon, T0IE);            // Disable Timer 0 Interrupts
     clear_bit(intcon, GIE);             // Disable Global Interrupts
     clear_bit(intcon, T0IF);
 }
  }
 tmr0 = CLEAR ;
 tmr0 = tmrOffset ;
}
void main()
{
   // sets up the calibration of Osscal
 asm{
 bsf _status,RP0
        call 0x3ff
        movwf _osccal
        bcf _status,RP0
 }// end asm
// sound the buzzer once and light the led for a second
   init() ;
   gpio.1 = 1 ;         // turn on the led
   sound(200,255,10);  // makes a beep noise for number of reps
   gpio.1 = 0 ; // turn this off
 //main program loop start here
 while(1)
  {
        // check to see if timer is on Zero indicates off
        if(timer == 0)
        {
         swVal= getKeyPress();
 if(swVal==1)
 { TMRFlag = 0x00 ;
     tmrOffset  = 188 ;
 timer =  startTimer(tmrOffset) ;
 gpio.1 = 1;
 }
         }
   }
}