/*  LCD V-Meter 6bit
    2011/02/06    AT90S2313       2/13 BY M.Kikuchi
    Used ROM (bytes): 1264 (62%)  Free ROM (bytes): 784 (38%)
*/

// Lcd pinout settings
sbit LCD_RS at PORTD0_bit;
sbit LCD_EN at PORTD1_bit;
sbit LCD_D4 at PORTD2_bit;             // LCD_D4-D7 LCDPin
sbit LCD_D5 at PORTD3_bit;
sbit LCD_D6 at PORTD4_bit;
sbit LCD_D7 at PORTD5_bit;

// Pin direction
sbit LCD_RS_Direction at DDD0_bit;
sbit LCD_EN_Direction at DDD1_bit;
sbit LCD_D4_Direction at DDD2_bit;
sbit LCD_D5_Direction at DDD3_bit;
sbit LCD_D6_Direction at DDD4_bit;
sbit LCD_D7_Direction at DDD5_bit;

char AD_Converter(){                   // 6bit 0-63
     char     i,AD_TEMP;
     
     DDRB=0b11111100;                  // 1=out 0=in
     ACD_bit = 0;                      // 0=active
     PORTB = 0;                        // to ACO=1
     for (i = 0;i < 64;i ++){
         PORTB = (i<<2) & 0b11111100;  //6bit
         if (ACO_bit==0){
            AD_TEMP = i;
            i = 64;
         }
     }
     ACD_bit = 1;
     DDRB = 0;                         //0=in
     return (AD_TEMP);
}

void main() {
     char   TEMP,ad10,ad1,Flag;
//
     DDRB = 0;                         //1=out 0=in
     DDRD = 0b01111111;
     PORTD = 0xff;
//
     Lcd_Init();                       // Initialize LCD
     Lcd_Cmd(_LCD_CLEAR);              // Clear display
     Lcd_Cmd(_LCD_CURSOR_OFF);         // Cursor off
//
     while(1){
         TEMP = AD_Converter();
         if ((TEMP & 1)==1)
            Flag = 0x35;               //0.5V check
         else
            Flag = 0x30;
         TEMP >>= 1;
// 文字列に変更する
         ad10 =(TEMP/10)+0x30;         // 10 V
         if (ad10==0x30)
              ad10=0x20;
         ad1  =(TEMP%10)+0x30;         // 1 V
         Lcd_Chr(1, 2, ad10);
         Lcd_Chr_Cp(ad1);
         Lcd_Chr_Cp('.');
         Lcd_Chr_Cp(Flag);
         Lcd_Chr_Cp(' ');
         Lcd_Chr_Cp('V');
         Delay_ms(300);
     }
}