// MCU BASIC: https://www.basic4mcu.com
// DateTime : 2018-12-09 오후 3:01:29
// by Ok-Hyun Park
//
#include <avr/io.h>
#define F_CPU 16000000UL
#include <util/delay.h>
#include <avr/interrupt.h>
//
#define    TRIG1     PORTA|=0x40  // 트리거 출력 PA6
#define    TRIG0     PORTA&=~0x40 
#define    ECHO      (PINA&0x80)  // Echo 입력 PA7
//
#define BIT4_LINE2_DOT58        0x28 // 4 Bit Mode,2 Lines,5x8 Dot
#define DISPON_CUROFF_BLKOFF    0x0C // Display On,Cursor Off,Blink Off
#define DISPOFF_CUROFF_BLKOFF   0x08 // Display Off,Cursor Off,Blink Off
#define INC_NOSHIFT             0x06 // Entry Mode,Cursor Increment,Display No Shift
#define DISPCLEAR               0x01 // Display Clear,Address 0
#define CURHOME                 0x02 // Cursor Home
#define CUR1LINE                0x80
#define CUR2LINE                0xC0
//
char CLCD_NUM[]="000.0";
char state=0;
int  distance_1st,distance_2nd,height,number;
//-------------------------------------------------
void CLCD_cmd(char cmd){
  PORTC=cmd&0xf0; PORTD=0x10; _delay_us(1); PORTD=0;
  PORTC=cmd<<0x4; PORTD=0x10; _delay_us(1); PORTD=0; _delay_ms(5);
}
//
void CLCD_data(char data){
  PORTC=data&0xf0; PORTD=0x14; _delay_us(1); PORTD=4;
  PORTC=data<<0x4; PORTD=0x14; _delay_us(1); PORTD=4; _delay_us(50);
}
//
void CLCD_puts(char *s){ while(*s)CLCD_data(*s++); }
//
void CLCD_num_display(int n){
  CLCD_NUM[0]=(n/1000)%10+0x30;
  CLCD_NUM[1]=(n/100)%10+0x30;
  CLCD_NUM[2]=(n/10)%10+0x30;
  CLCD_NUM[3]='.';
  CLCD_NUM[4]=n%10+0x30;
  CLCD_NUM[5]=0; //null
  CLCD_puts(CLCD_NUM);
}
//
void init_CLCD(){
  _delay_ms(50);
  CLCD_cmd(BIT4_LINE2_DOT58); CLCD_cmd(DISPON_CUROFF_BLKOFF);
  CLCD_cmd(INC_NOSHIFT);      CLCD_cmd(DISPCLEAR);
}
//-------------------------------------------------
unsigned int read_distance(){
  unsigned int distance=0;
  TRIG1; _delay_us(10); TRIG0;
  while(!ECHO); TCNT1=0; TCCR1B=2; //0.5us
  while( ECHO); TCCR1B=0;
  distance=TCNT1;
  distance=(unsigned int)((float)distance/11.6);
  return(distance);
}
//-------------------------------------------------
void menu0(){
  CLCD_cmd(DISPCLEAR);
  CLCD_cmd(CUR1LINE); CLCD_puts("If Ready");
  CLCD_cmd(CUR2LINE); CLCD_puts("Press Switch!");
  state=1;
}
//-------------------------------------------------
void menu1(){
  distance_1st=read_distance(); //초음파센서
  CLCD_cmd(DISPCLEAR);
  CLCD_cmd(CUR1LINE); CLCD_puts("First: "); CLCD_num_display(distance_1st);
  state=2;
}
//-------------------------------------------------
void menu2(){
  distance_2nd=read_distance(); //초음파센서
  CLCD_cmd(CUR2LINE); CLCD_puts("Second: "); CLCD_num_display(distance_2nd);
  state=3;
}
//-------------------------------------------------
void menu3(){
  CLCD_cmd(DISPCLEAR);
  CLCD_cmd(CUR1LINE); CLCD_puts("Height: ");
  height=distance_2nd-distance_1st;
  if(height<0)CLCD_puts("Error!");
  else        CLCD_num_display(height);
  state=0;
}
//-------------------------------------------------
ISR(INT4_vect){
  _delay_ms(100); EIFR|=1x10; if(PINE&=0x10)return; // 채터링 return
  //-------------------------------------------------------------------
  switch(state){ // 스위치 누른 횟수
    case 0: menu0(); break;
    case 1: menu1(); break;
    case 2: menu2(); break;
    case 3: menu3(); break;
  }
}
//-------------------------------------------------
void TX0_char(char c){ while(!(UCSR0A&0x20)); UDR0=c; }
void TX0_STR(char *s){ while(*s)TX0_char(*s++); }
//-------------------------------------------------
interrupt [USART0_RXC] void usart0_rx_isr(void){         // 수신 인터럽트
  char r;
  r=UDR0;
  if(r=='0')menu0();
  if(r=='1')menu1();
  if(r=='2')menu2();
  if(r=='3')menu3();
}
//
int main(void){
  DDRA=0x40;   // 초음파거리센서 TRIG(PA6,출력),ECHO(PA7,입력)
  DDRC=0xFF;   // CLCD PORT(data&command)
  DDRD=0x1C;   // CLCD PORT(control 출력: RS=bit2,RW=bit3,E=bit4)
  PORTE=0x10;  // SW1 내부플업저항
  init_CLCD();
  UCSR0B=0x98; UBRR0L=103; // 9600 
  EICRB=0xAA;  EIMSK=0x10; // INT4 하강 에지(Fallin Edge)
  SREG|=0x80;
  while(1){}
}