까만배경에 흰선을 따라가는 라인트레이서 제작중입니다.
3개의 IR센서 사용하고 2상스텝모터 사용합니다
 
아래 코딩에서 빨간글씨로 된 부분에서 else if , else문으로 큰좌회전 / 작은좌회전 / 큰우회전 / 작은우회전 / 직진 나눴었는데
PID제어중 P제어를 사용하면 쉽게 주행이 가능하다고 하는데 이해가 잘 안가네요
도와주시면 감사하겠습니다.
 
#include <avr/io.h>
#include <avr/interrupt.h>
typedef unsigned int WORD;
typedef unsigned char BYTE;
#define SenserNum 3
#define BAUD_38400 25
WORD speed_L;
WORD speed_R;
WORD ADC_Data[SenserNum];
int state;
int count_R,count_L,CrossCount,StopState;
int Left_Sum,Right_Sum,Center_Sum;
unsigned char left_motor[8] = { 0x11,0x33,0x22,0x66,0x44,0xcc,0x88,0x99}; //1-2 Phase Control Method
unsigned char right_motor[8] = { 0x99,0x88,0xcc,0x44,0x66,0x22,0x33,0x11};
;
void PORT_init(void)
{
DDRE = DDRF = DDRG = 0; //Set port to input direction first.
PORTA = PORTB = PORTC = PORTD = PORTE = PORTF = PORTG = 0x00; //
DDRA = 0XFF;
DDRB = 0xFF;
DDRC = 0xFF;
DDRD = 0xFF;
DDRE = 0xFF;
}
void ADC_init(void)
{
ADMUX = 0;
ADCSRA = (1<<ADEN)|(1<<ADFR)|(1<<ADSC)|(1<<ADIE)|(1<<ADPS2)|(ADPS1)|(1<<ADPS0);
for(int i =0; i<SenserNum; i++)
{
ADC_Data[i]=0;
}
}
void Timer_init(void)
{
TCCR1B = (1<<CS10);
TCNT1 = speed_R;
TCCR3B = (1<<CS30);
TCNT3 = speed_L;
TIMSK = (1<<TOIE1);
ETIMSK = (1<<TOIE3);
}
void Delay_us(unsigned char time_us)
{
register unsigned char i;
for(i = 0; i < time_us; i++) {
asm (" PUSH R0 ");
asm (" POP R0 ");
asm (" PUSH R0 ");
asm (" POP R0 ");
asm (" PUSH R0 ");
asm (" POP R0 ");
}
}
void Delay_ms(unsigned int time_ms)
{
register unsigned int i;
for(i = 0; i < time_ms; i++)
{
Delay_us(250);
Delay_us(250);
Delay_us(250);
Delay_us(250);
}
}
void Set_Speed(void)
{
   Left_Sum = ADC_Data[1];
   Center_Sum = ADC_Data[2];
   Right_Sum = ADC_Data[3];
   if(Center_Sum < 100) {
      speed_L = 20000;
      speed_R = 35000;
      state=1;
   }else{
      speed_L = 35000;
      speed_R = 20000;
      state=3;
   }
}
void USART_init(unsigned int baud0,unsigned int baud1)
{
UBRR0H = (unsigned char)(baud0 >> 8);
UBRR0L = (unsigned char)baud0;
UCSR0B = (0<<RXEN0)|(1<<TXEN0)|(0 << RXCIE0)|(0 << TXCIE0);
UCSR0C = (1<<UCSZ01)|(1<<UCSZ00);
UBRR1H = (unsigned char)(baud1 >> 8);
UBRR1L = (unsigned char)baud1;
UCSR1B = (0<<RXEN1)|(1<<TXEN1)|(0<<RXCIE1)|(0<<TXCIE1);
UCSR1C = (1<<UCSZ11)|(1<<UCSZ10);
}
void Txd0Byte(unsigned char datum)
{
while(!(UCSR0A & (1<<UDRE0)));
UDR0 = datum;
}
void Txd1Byte(unsigned char datum)
{
while(!(UCSR1A & (1<<UDRE1)));
UDR1 = datum;
}
unsigned char Rxd0Byte(void)
{
while(!(UCSR0A & (1 << RXC0)));
return UDR0;
}
unsigned char Rxd1Byte(void)
{
while(!(UCSR1A & (1 << RXC1)));
return UDR1;
}
void Txd0String(char *str)
{
int i;
for( i=0; str[i]!=0; i++)
Txd0Byte( str[i]);
}
void Txd1String(char *str)
{
int i;
for( i=0; str[i]!=0; i++)
Txd1Byte( str[i]);
}
void Txd0Dec(int dec)
{
char String[5];
int loop;
for (loop = 0 ; loop <5 ; loop++)
{
String[loop] = 0x30 + (dec % 10);
dec = dec / 10;
}
for(loop = 4; loop >= 0; loop --)
Txd0Byte(String[loop]);
}
void Txd1Dec(int dec)
{
char String[5];
int loop;
for (loop = 0 ; loop <5 ; loop++)
{
String[loop] = 0x30 + (dec % 10);
dec = dec / 10;
}
for(loop = 4; loop >= 0; loop --)
Txd1Byte(String[loop]);
}
int main (void)
{
USART_init(BAUD_38400,BAUD_38400);
PORT_init();
Timer_init();
ADC_init();
count_R = 0;
count_L = 0;
CrossCount = 0;
StopState = 0;
state = 0;
sei();
for(;;){
Delay_ms(100);
PORTA =~PORTA;
Txd1Dec(ADC_Data[0]);
Txd1Byte(' ');
Txd1Dec(ADC_Data[1]);
Txd1Byte(' ');
Txd1Dec(ADC_Data[2]);
Txd1Byte(' ');
Txd0Dec(ADC_Data[0]);
Txd0Byte(' ');
Txd0Dec(ADC_Data[1]);
Txd0Byte(' ');
Txd0Dec(ADC_Data[2]);
Txd0Byte(' ');
if(state==1) Txd1String("Left Corner");
else if (state==2)  Txd1String("Left");
else if (state==3)  Txd1String("Right Corner");
else if (state==4)  Txd1String("Right");
else Txd1String("Straight");
Txd1Byte('\n');
}
return 0;
}
SIGNAL(TIMER1_OVF_vect)
{
PORTB = right_motor[count_R++];
count_R %=8;
Set_Speed();
TCNT1 = speed_R;
}
SIGNAL(TIMER3_OVF_vect)
{
PORTC= left_motor[count_L++];
count_L %= 8;
Set_Speed();
TCNT3 = speed_L;
}
SIGNAL(ADC_vect)
{
ADC_Data[ADMUX] = ADC ;
ADMUX++;
ADCSRA = (1<<ADEN)|(1<<ADFR)|(1<<ADSC)|(1<<ADIE)|(1<<ADPS2)|(ADPS1)|(1<<ADPS0);
ADMUX %= SenserNum;
}