/*
Power Shutdown circuit for LiPo and LiFe
PIC12F675

GP5 NC
GP4 NC
GP3 NC
GP2 LED
GP1 FET-OFF
GP0 AN-INPUT

LiPo
1S 3-4.2V
2S 6-8.4V
3S 9-12.6V
4S 12-16.8V

128*1.4=179.2
179-128=51
*/
#define stop_count 100

#define LED GPIO.GPIO2
#define OUT GPIO.GPIO1
unsigned short voltage;
unsigned short count;
unsigned short time1;
unsigned short time2;
unsigned short flag;
unsigned short pres;

void interrupt(){
  if(INTCON.T0IF){
    INTCON.T0IF=0;
    flag|=0x01;
    if(!ADCON0.GO_DONE){
      ADCON0.GO_DONE=1;
    }
  }
  return;
}

void init(){
  TRISIO=0x39;
  GPIO=0x00;
  ANSEL=0x61;
  ADCON0=0x01;
  OPTION_REG=0xD7;
  INTCON=0xE0;
  return;
}


main(){
  init();
  OUT=0;
  LED=1;
  count=0;
  pres=0;
  while(1){
    if(PIR1.ADIF){
      PIR1.ADIF=0;
      voltage=ADRESH;
      if(voltage<=127){
        time2=0;
        if(count>=stop_count){
          OUT=1;
          while(1);
        }else{
          count++;
        }
      }else{
        count=0;
        time2=voltage-127;
      }

    }

    if(flag&0x01){
      pres++;
      if(time2>=51){
        LED=1;
        time1=0;
      }else if(time2==0){
        LED=0;
      }else if(time1>=time2){
        time1=0;
        LED=!LED;
      }else if(pres==0){
        time1++;
      }
    }

  }
}