ATMEGA8超聲波測距程序

做了一個超聲波蔽障 現(xiàn)在小車可以光電循跡 和超聲波蔽障了 下面是

超聲波的程序

/*********************************************************************
Project :超聲波測距
Chip type : ATMEGA8
Clock frequency: 8.000000MHz
*********************************************************************/
#include
#include
#pragma interrupt_handler intt0:10 //T0溢出中斷
#pragma interrupt_handler icp_timer1:6 // T1捕捉中斷
const unsigned char tab1[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};//七段譯碼字型表(lm,cm)
unsigned char ledbuff[]={0X08,0X28,0X28};//顯示緩沖區(qū)
unsigned char count;
unsigned char newcount;
unsigned char oldcount;
void intt0(void)//T0中斷定時程序，定時58US,即測距1CM.
{
TCNT0=0XC6;
count++;
}
void icp_timer1(void)//ICP1捕捉中斷，捕捉頻率38.5～41.6
{
if (96<=ICR1<=104)
{
SREG&=0X7f;
newcount=count-13;
ICR1=0;
TCNT1=0;
TCCR1B=0X81;
}
}
void delay_1us(void)//1us
{
asm("nop");
}
void delay_us(unsigned int t)//tus
{
unsigned int i=0;
for(i=0;idelay_1us();
}
void delay_1ms(void)//1ms
{
unsigned int i;
for(i=1;i<1142;i++);
}
void delay_ms(unsigned char t)
{
unsigned char i=0;
for(i=0;i{
delay_1ms();
}
}

void send40kHz(void) //發(fā)射40KHz超聲波
{
count=0;
TIMSK&=0XDF;//禁止ICP1使能
OCR2=0X64;
TCCR2=0X19;
}
void close40kHz(void) //停止發(fā)射超聲波
{
TCCR2=0X00;
}
void hextobcd(unsigned char m)//將count十六進制數(shù)據(jù)轉(zhuǎn)換為LED七段碼
{
unsigned char temp;
temp=m%10;
ledbuff[0]=tab1[temp];//mm位
m=m/10;
temp=m%10;
ledbuff[1]=tab1[temp];//lm位
temp=m/10;
ledbuff[2]=tab1[temp];//m位
}
void display3led(void) //數(shù)碼管顯示
{
unsigned char i;
for(i=0;i<3;i++)
{
PORTD=ledbuff[i];
PORTC=~(1< delay_us(100);
PORTC=(1<}
}

void mcu_init(void)//MCU初始化
{
DDRD=0XFF;
PORTD=0XFF;
DDRC=0XDF; //PC5為輸入
PORTC=0XFF;
DDRB=0XFE;
PORTB=0XF7;
TCNT2=0X00;
TCNT0=0XC6; //T0定時58US
TCCR0=0X02; //T0定時器1/8分頻
TCNT1=0X00;
TCCR1A=0X00;
TCCR1B=0X81; //輸入捕獲噪音抑制允許，ICP1下降沿觸發(fā)，系統(tǒng)時鐘
TIMSK=0X01; //使能T0定時溢出

}
void main(void)
{
unsigned char i;
mcu_init();
for(;;)
{
send40kHz();
SREG|=0X80;
delay_us(50);
close40kHz();
delay_us(20);
TIMSK=0X21;
if (newcount!=oldcount)
oldcount=newcount;
hextobcd(oldcount);
for(i=0;i<20;i++)
display3led();
}

}