volatile char *AD_MUX = (char*)0x7C; 
volatile char *ADC_SRB = (char*)0x7B;
volatile char *ADC_SRA = (char*)0x7A;
volatile short *ADC_LH = (short*)0x78;

short prev;
char count = 1;
void setup() {
  Serial.begin(9600);
  init_timer();
  init_port();
  lcd_init();
}

void init_timer(){
  volatile char *TCCR1_A = 0x80;
  volatile char *TCCR1_B = 0x81;
  volatile short *TCNT_1 = 0x84;
  volatile short *OCR1_A = 0x88;
  volatile char *TIMSK_1 = 0x6F;

  *TCCR1_A = 0;
  *TCCR1_B = 0x0C;
  *TCNT_1  = 0;
   
  *OCR1_A  = 60000;
  *TIMSK_1 = 0x03;
}

ISR(ADC_vect){
  // Serial.println(*ADC_LH);
  if(prev==1000 && *ADC_LH==0){
    // incr_cursor();
    write_lcd(" ");
    count++;
    // Serial.println(count,DEC);
    // Serial.println("Right");
  }else if(prev==1000 && *ADC_LH==1023){
    decr_cursor();
    write_lcd(" ");
    // count--;
    // Serial.println(count,DEC);
    // Serial.println("left");
  }

  // if(count==0){
  //   second_line();
  //   write_lcd(' ');
  // }

  prev = *ADC_LH;
}

ISR(TIMER1_COMPA_vect){
  adc_read();
}


void init_port(){
  volatile char *ddr1 = (char*)0x107;
  *ddr1 = 0x0FF;

  volatile char *ddr2 = (char*)0x10A;
  *ddr2 = 0x0F;
}

void control_lcd(char data){
  volatile char *out = (char*)0x10B;
  *out = data;
}

void data_lcd(char data){
  volatile char *out = (char*)0x108;
  *out = data;
}


void lcd_init(){
  data_lcd(0x38);
  enable();
  data_lcd(0x80);
  enable();
  data_lcd(0x0F);
  enable();
}

void write_lcd(char data){
  data_lcd(data);
  register_enable();
}

void register_enable(){
  control_lcd(0x02);
  delay1();
  control_lcd(0x03);
  delay1();
}

void enable(){
  control_lcd(0x01);
  delay1();
  control_lcd(0x00);
  delay1();
}

void adc_read(){
  *AD_MUX = 0b11000000;
  *ADC_SRA = 0b11011111;
}

void incr_cursor(){
  data_lcd(0x38);
  enable();
  data_lcd(0x06);
  enable();
  // data_lcd(0x0F);
  // enable();
}

void decr_cursor(){
 data_lcd(0x38);
  enable();
  data_lcd(0x04);
  enable();
  // data_lcd(0x0F);
  // enable();
}

void second_line(){
  data_lcd(0x38);
  enable();
  data_lcd(0xC0);
  enable();
}

void delay1(){
  volatile long i;
  for(i=0;i<1000;i++);
}

void loop() {
  // put your main code here, to run repeatedly:

}