/*****************************************************
File name	    : demo_10_3.c
Chip type           : ATmega16L
Program type        : Application
Clock frequency     : 4.000000 MHz
Memory model        : Small
External SRAM size  : 0
Data Stack size     : 256
*****************************************************/

#include <mega16.h>
	#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

flash unsigned char led_7[10]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};   //共陽極數(shù)碼管
flash unsigned char position[4]={0x80,0x40,0x20,0x10};    //位選

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;
		adc /= 10;
	}
}

// Timer 0 比較匹配中斷服務(wù)
interrupt [TIM0_COMP] void timer0_comp_isr(void)
{
	time_2ms_ok = 1;
}

// ADC 轉(zhuǎn)換完成中斷服務(wù)
interrupt [ADC_INT] void adc_isr(void)
{
    unsigned int adc_data,adc_v;
    adc_data=ADCH;                             //讀取ADC置換結(jié)果
    adc_v=(unsigned long)adc_data*5000/256;    //換算成電壓值
    adc_to_disbuffer(adc_v);
}

void display(void)	// 4位LED數(shù)碼管動態(tài)掃描函數(shù)
{
        PORTC &= 0xf0;
	PORTD = led_7[dis_buff[posit]];
	if (posit==3) PORTD &=~0x80;
	PORTC |= position[posit];
	if (++posit >=4) posit = 0;
}

void main(void)
{
	DDRC=0xFF;
	PORTC=0xFF;
	DDRD=0xFF;       // LED顯示控制I/O端口初始化
	PORTD=0x00;

    // T/C0 初始化
	TCCR0=0x0B;     // 內(nèi)部時鐘，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=0x67;     // 參考電源AVcc、ADC7單端輸入,左對齊
    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、自動觸發(fā)轉(zhuǎn)換、ADC轉(zhuǎn)換中斷允許、ADCclk=125Kz

    #asm("sei")     // 開放全局中斷

    while (1)
    {
        if (time_2ms_ok)
        {
        	display();  	// LED掃描顯示
            time_2ms_ok = 0;
        }
    }
}