/*****************************************************
Chip type           : ATmega16
Program type        : Application
Clock frequency     : 8.000000 MHz
Memory model        : Small
External SRAM size  : 0
Data Stack size     : 256
*****************************************************/

#include <mega8.h>
#include <delay.h>

#define ADC_VREF_TYPE 0xC0
// Declare your global variables here

flash unsigned char LedCode[10]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};
flash unsigned char LedPos[3]={0xFE,0xFD,0xFB};

unsigned char i,tmp,disbuf[4],mode,key,dismod,keyval;
unsigned int mask,alltmp,adtmp[8],keycnt;

void display(unsigned char data,unsigned char pos)
{
PORTB=PORTB&(LedPos[pos]);
if (pos==2){
PORTD=LedCode[data]&0x7F;
}
else
PORTD=LedCode[data];
}

// Read the AD conversion result 
unsigned int read_adc(unsigned char adc_input)
{
ADMUX=adc_input | (ADC_VREF_TYPE & 0xff);
// Delay needed for the stabilization of the ADC input voltage
delay_us(10);
// Start the AD conversion
ADCSRA|=0x40;
// Wait for the AD conversion to complete
while ((ADCSRA & 0x10)==0);
ADCSRA|=0x10;
return ADCW;
}

void adcon()
{
      read_adc(2);
      read_adc(2);
      for (i=0;i<8;i++)
      {
      //因为采用内部参考,为了测到5V左右,用了两个560K电阻分压
      //虽然两电阻已经精选过了,但是还是有误差,所以乘了5220(本来选用内部参考应该乘5120的)
      adtmp[i]=(unsigned long)read_adc(2)*5220/1024;
      alltmp+=adtmp[i];
      }
      alltmp/=8;
      tmp=alltmp%10;
      if (tmp>4)
        alltmp=alltmp/10+1;
      else
        alltmp/=10;
      
}
void keyscan()
{
      switch(mode)
      {
      case 0:   
        key=PINB&0x38;
        if (key!=0x38)
        mode=1;
        break;
      case 1:
        key=PINB&0x38;
        if (key!=0x38)
        {
         mode=2;
         keycnt=0;
        if (PINB.5==0)
        keyval=0;
        else if ((PINB.4==0)&&(dismod==1))
        keyval=1;
        else if ((PINB.3==0)&&(dismod==1))
        keyval=2;               
         }
        break;     
      case 2:
        key=PINB&0x38;
        if (key==0x38)
        {
        mode=0;
        if (keyval==0)
        dismod^=0x01;
        if (keyval==1)
        mask+=1;
        if (keyval==2)
        mask-=1;
        keyval=0x0f;       
        }
        else if (++keycnt>=100)
        {
        mode=3;
        if (keyval==0)
        dismod^=0x01;
        keycnt=0;
        if (keyval==1)
        mask+=10;
        if (keyval==2)
        mask-=10;
        }
        break;
      case 3:
        key=PINB&0x38;
        if (key==0x38)
        {
        mode=0;
        keyval=0x0f;
        }
        else if (++keycnt>=50)
        {
        keycnt=0;
        if (keyval==0)
        dismod^=0x01;
        if (keyval==1)
        mask+=10;
        if (keyval==2)
        mask-=10;
        } 
        break;
      }
}


void main(void)
{
// Declare your local variables here

PORTB=0xFF;
DDRB=0xC7;

PORTC=0x00;
DDRC=0x00;

PORTD=0xFF;
DDRD=0xFF;

// ADC initialization
// ADC Clock frequency: 691.200 kHz
// ADC Voltage Reference: Int., cap. on AREF
// ADC Auto Trigger Source: None
ADMUX=0xC2;
ADCSRA=0x86;

mask=375;
alltmp=0;
mode=0;
dismod=0;
keycnt=0;

while (1)
      {
      // Place your code here
      //进行温度转换,结果保存于alltmp中
      adcon();
      //读取键值
      keyscan();
      //mask为无符号型,故只需判断上限
      if (mask>499) mask=0;
      
      //判断测得电压是否达到规定电压?
      if (dismod==0)
      {
      if (alltmp>=mask)
      PORTB&=~(1<<7);        //达到规定电压,蜂鸣器鸣叫
      else
      PORTB|=(1<<7);        //否则,关蜂鸣器
      }
      
      if (dismod==0)      //当前是不是显示电池电压状态
      {
      PORTB|=(1<<6);          //设置指示灯灭
      for (i=0;i<3;i++)       //显示缓存为电压值
      {
       disbuf[i]=alltmp%10;
       alltmp/=10;
      }
      }
      else                 //不是,当前为设定电压状态
      {
      alltmp=mask;
      PORTB|=(1<<7);           //关蜂鸣器
      PORTB&=~(1<<6);        //亮设置指示灯
      for (i=0;i<3;i++)      //显示缓存为设定值
      {
       disbuf[i]=mask%10;
       mask/=10;
       }
      mask=alltmp;    
      }
      
      for (i=0;i<3;i++)      //显示数据
      {
       PORTB|=0x07;
       display(disbuf[i],i);
       delay_ms(4);
      }
      
      };
}