//********************************************************************** 
/*
　　＜簡易電圧計（高分解能22ビット）＞ 
*/
//********************************************************************** 
//■マクロ定義 
#define BYTE        unsigned short
#define WORD        unsigned int
#define DWORD       unsigned long
//LCD
sbit LCD_RS at RB6_bit;
sbit LCD_EN at RB7_bit;
sbit LCD_D7 at RA1_bit;
sbit LCD_D6 at RA0_bit;
sbit LCD_D5 at RA7_bit;
sbit LCD_D4 at RA6_bit;
sbit LCD_RS_Direction at TRISB6_bit;
sbit LCD_EN_Direction at TRISB7_bit;
sbit LCD_D7_Direction at TRISA1_bit;
sbit LCD_D6_Direction at TRISA0_bit;
sbit LCD_D5_Direction at TRISA7_bit;
sbit LCD_D4_Direction at TRISA6_bit;
//
#define INPUT_MODE  1
#define OUTPUT_MODE 0
//********************************************************************** 
//■関数宣言 
extern  void    main();
extern  long    mcp3551_read();
extern  void    mcp3551_init();
//********************************************************************** 
//■メイン関数 
void    main()
{
        double  v1;
        WORD    v2;
        short   cnt;
        char    buf1[16], buf2[16];
        char    *space = "             ";
        //
        OSCCON = 0b01110000;
        ANSEL  = 0b00000100;
        TRISA  = 0b11111111;
        TRISB  = 0b00000100;
        //
        mcp3551_init();
        ADCON1.VCFG1 = 1;
        ADCON1.VCFG0 = 0;
        ADC_Init();
        //
        Lcd_Init();
        Lcd_Cmd(_LCD_CURSOR_OFF);
        Lcd_Cmd(_LCD_CLEAR);
        Lcd_Out(1, 1, "Voltmeter(22bit)");
        Delay_ms(1000);
        Lcd_Cmd(_LCD_CLEAR);
        //
        while (1) {
        	//測定 
                v1 = mcp3551_read();
                v2 = ADC_Get_Sample(2);
                //補正 
                v1 = v1 * 0.9765625;  // 分解能＝0.9765625uV = 4096000uV ÷ 4194304 
                v2 = v2 * 4;          // 分解能＝4mV = 4096mV ÷ 1024
                //表示 
                FloatToStr(v1, buf1);
                WordToStr(v2, buf2);
                Lcd_Out(1, 1, "uV:");
                Lcd_Out(2, 1, "mV:");
                Lcd_Out(1, 4, space);
                Lcd_Out(2, 4, space);
                Lcd_Out(1, 4, buf1);
                Lcd_Out(2, 4, &buf2[1]);
                //
                Delay_ms(500);
        }
}
//**********************************************************************
//MCP3551
sbit  CS   at RB1_bit;
sbit  SDO  at RB2_bit;
sbit  SCK  at RB3_bit;
sbit  CS_Direction   at  TRISB1_bit;
sbit  SDO_Direction  at  TRISB2_bit;
sbit  SCK_Direction  at  TRISB3_bit;
//
void    mcp3551_init()
{
	CS_Direction  = OUTPUT_MODE;
	SDO_Direction = INPUT_MODE;
	SCK_Direction = OUTPUT_MODE;
	//
        CS = 1;
        SCK = 1;
}
//**********************************************************************
long    mcp3551_read()
{
        long    dat;
        short   cnt;
        //
        dat = 0;
        CS = 0;
        while (SDO == 1)
                ;
        for (cnt = 0; cnt < 24; cnt++) {
                SCK = 0;
                SCK = 1;
                if (SDO == 1) {
                        dat |= 0x01;
                }
                dat <<= 1;
        }
        CS = 1;
        return (dat & 0b001111111111111111111111);
}
//**********************************************************************