/*****************************************************
File name			: 
Chip type           : ATmega16L
Program type        : Application
Clock frequency     : 4.000000 MHz
Memory model        : Small
External SRAM size  : 0
Data Stack size     : 256
*****************************************************/

// CodeVisionAVR C Compiler
// (C) 1998-2001 Pavel Haiduc, HP InfoTech S.R.L.

// I/O registers definitions for the ATmega16


#pragma used+
#pragma used+
sfrb TWBR=0;
sfrb TWSR=1;
sfrb TWAR=2;
sfrb TWDR=3;
sfrb ADCL=4;
sfrb ADCH=5;
sfrw ADCW=4;      // 16 bit access
sfrb ADCSRA=6;
sfrb ADMUX=7;
sfrb ACSR=8;
sfrb UBRRL=9;
sfrb UCSRB=0xa;
sfrb UCSRA=0xb;
sfrb UDR=0xc;
sfrb SPCR=0xd;
sfrb SPSR=0xe;
sfrb SPDR=0xf;
sfrb PIND=0x10;
sfrb DDRD=0x11;
sfrb PORTD=0x12;
sfrb PINC=0x13;
sfrb DDRC=0x14;
sfrb PORTC=0x15;
sfrb PINB=0x16;
sfrb DDRB=0x17;
sfrb PORTB=0x18;
sfrb PINA=0x19;
sfrb DDRA=0x1a;
sfrb PORTA=0x1b;
sfrb EECR=0x1c;
sfrb EEDR=0x1d;
sfrb EEARL=0x1e;
sfrb EEARH=0x1f;
sfrw EEAR=0x1e;   // 16 bit access
sfrb UBRRH=0x20;
sfrb UCSRC=0X20;
sfrb WDTCR=0x21;
sfrb ASSR=0x22;
sfrb OCR2=0x23;
sfrb TCNT2=0x24;
sfrb TCCR2=0x25;
sfrb ICR1L=0x26;
sfrb ICR1H=0x27;
sfrb OCR1BL=0x28;
sfrb OCR1BH=0x29;
sfrw OCR1B=0x28;  // 16 bit access
sfrb OCR1AL=0x2a;
sfrb OCR1AH=0x2b;
sfrw OCR1A=0x2a;  // 16 bit access
sfrb TCNT1L=0x2c;
sfrb TCNT1H=0x2d;
sfrw TCNT1=0x2c;  // 16 bit access
sfrb TCCR1B=0x2e;
sfrb TCCR1A=0x2f;
sfrb SFIOR=0x30;
sfrb OSCCAL=0x31;
sfrb OCDR=0x31;
sfrb TCNT0=0x32;
sfrb TCCR0=0x33;
sfrb MCUCSR=0x34;
sfrb MCUCR=0x35;
sfrb TWCR=0x36;
sfrb SPMCR=0x37;
sfrb TIFR=0x38;
sfrb TIMSK=0x39;
sfrb GIFR=0x3a;
sfrb GICR=0x3b;
sfrb OCR0=0X3c;
sfrb SPL=0x3d;
sfrb SPH=0x3e;
sfrb SREG=0x3f;
#pragma used-

// Interrupt vectors definitions


// Needed by the power management functions (sleep.h)
#asm
	#ifndef __SLEEP_DEFINED__
	#define __SLEEP_DEFINED__
	.EQU __se_bit=0x40
	.EQU __sm_mask=0xB0
	.EQU __sm_powerdown=0x20
	.EQU __sm_powersave=0x30
	.EQU __sm_standby=0xA0
	.EQU __sm_ext_standby=0xB0
	.EQU __sm_adc_noise_red=0x10
	.SET power_ctrl_reg=mcucr
	#endif
#endasm



flash unsigned char led_7[10]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F};//段選碼
flash unsigned char position[6]={0xFB,0xF7,0xEF,0xDF,0xBF,0x7F};                  //位選碼

unsigned char dis_buff[4]={0,0,0,0},posit;
bit time_2ms_ok;

// ADC電壓值送顯示緩沖區(qū)函數(shù)
void adc_to_disbuffer(unsigned int adc)		
{
	unsigned char i;
	for (i=0;i<=3;i++)
	{
		dis_buff[i]=adc%10;     //將電壓值分解成四位數(shù)碼管顯示
		adc /= 10; 
	}
}

// Timer 0 比較匹配中斷服務(wù),2ms發(fā)生一次計(jì)時(shí)中斷
interrupt [20] void timer0_comp_isr(void)
{
	time_2ms_ok = 1;
}

// ADC 轉(zhuǎn)換完成中斷服務(wù)
interrupt [15] void adc_isr(void)
{   
    unsigned int adc_data,adc_v;
    adc_data=ADCW;                  //讀取ADC置換結(jié)果                  
    adc_v=(unsigned long)adc_data*5000/1024;    //換算成電壓值
    adc_to_disbuffer(adc_v);               //將電壓值分解
}

void display(void)	// 4位LED數(shù)碼管動(dòng)態(tài)掃描函數(shù)
{
    PORTA |= 0xFF;	                //數(shù)碼管位選信號(hào)無(wú)效
	PORTC = led_7[dis_buff[posit]]; //數(shù)碼管段選信號(hào)
	if (posit==3) PORTC |= 0x80;    //當(dāng)PA5顯示時(shí)，要顯示小數(shù)點(diǎn)
	PORTA &= position[posit];       //數(shù)碼管位選信號(hào)有效
	if (++posit >=4 ) posit = 0;    //當(dāng)PA5顯示后，重新從PA2開(kāi)始顯示
}

void main(void)
{
	DDRA=0x3C;       //初始化PA2~PA5為輸出口
	PORTA=0x3C;		 
			
	DDRC=0xFF;      // LED顯示控制I/O端口初始化
	PORTC=0x00;
	// T/C0 初始化
	TCCR0=0x0B;     // 內(nèi)部時(shí)鐘，64分頻（4M/64=62.5KHz），CTC模式
	TCNT0=0x00;     
	OCR0=0x7C;      // OCR0 = 0x7C(124),(124+1)/62.5=2ms
	TIMSK=0x02;     // 允許T/C0比較中斷

    // ADC 初始化
    ADMUX=0x40;     // 參考電源AVcc、ADC0單端輸入
    SFIOR&=0x1F;    
    SFIOR|=0x60;    // 選擇T/C0比較匹配中斷為ADC觸發(fā)源
    ADCSRA=0xAD;    // ADC允許、自動(dòng)觸發(fā)轉(zhuǎn)換、ADC轉(zhuǎn)換中斷允許、ADCclk=125Kz
 
    #asm("sei")     // 開(kāi)放全局中斷

    while (1)
    {
        if (time_2ms_ok)     //每2ms成立一次，有T0控制
        {
        	display();  	// LED掃描顯示        
            time_2ms_ok = 0;
        }
    }
}