// CONFIG
#pragma config FOSC = INTOSCIO  // Oscillator Selection bits (INTRC oscillator; port I/O function on both RA6/OSC2/CLKO pin and RA7/OSC1/CLKI pin)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = ON       // Power-up Timer Enable bit (PWRT enabled)
#pragma config MCLRE = ON       // RA5/MCLR/VPP Pin Function Select bit (RA5/MCLR/VPP pin function is MCLR)
#pragma config BOREN = OFF      // Brown-out Reset Enable bit (BOR disabled)
#pragma config LVP = OFF        // Low-Voltage Programming Enable bit (RB3/PGM pin has digital I/O function, HV on MCLR must be used for programming)
#pragma config CPD = OFF        // Data EE Memory Code Protection bit (Code protection off)
#pragma config WRT = OFF        // Flash Program Memory Write Enable bits (Write protection off)
#pragma config CCPMX = RB2      // CCP1 Pin Selection bit (CCP1 function on RB2)
#pragma config CP = OFF         // Flash Program Memory Code Protection bit (Code protection off

#include <xc.h>
#include <stdlib.h>
#include "skSD1602LCD.h"

#define _XTAL_FREQ 8000000 //8MHz

#define CLK RB0
#define DAT RB1

#define LCD_RS    RB2
#define LCD_EN    RB3
#define LCD_D4    RB4
#define LCD_D5    RB5
#define LCD_D6    RB6
#define LCD_D7    RB7

#define WAIT_HIGH while(CLK == 0);
#define WAIT_LOW while(CLK == 1);

char getCharacter();

void main(void)
{
    OSCCON = 0b01110000; //周波数8MHz
    OPTION_REGbits.nRBPU = 0; //PORTBを内部プルアップ
    ADCON0 = 0b00000000; //ADコンバータOFF
    ADCON1 = 0b00000110; //RA2 RA3 Vref使わない
    TRISA  = 0b00000000; //全て出力
    TRISB  = 0b00000011; //RB0 RB1入力
    PORTA  = 0b00000000; //全てLOWにする
    PORTB  = 0b00000011;
    
    char ch;

    lcd_init() ;
    lcd_clear();
    
    while(1)
    {
        if(CLK == 0) //スタートビット
        {
            ch = getCharacter();
            switch(ch & 0xf0)
            {
                case 0x80:
                    lcd_setCursor(ch & 0xf, 0);
                    break;
                case 0x90:
                    lcd_setCursor(ch & 0xf, 1);
                    break;
                default:
                    lcd_putc(ch);
                    break;
            }
        }
    }
}

char getCharacter()
{
  unsigned char val, bi;

  val = 0;
  WAIT_HIGH
  for(int n = 0; n < 8; n++)
  {
    WAIT_LOW
    bi = DAT;
    val |= bi << n;
    WAIT_HIGH
  }

  return val;
}