模块：L298N，五路寻迹模块
不使用L298N上的EAEB引脚
#include <reg52.h>
// 电机控制引脚（P2口）
sbit IN1 = P2^3;
sbit IN2 = P2^2;
sbit IN3 = P2^1;
sbit IN4 = P2^0;
// 红外循迹传感器引脚（P1口）
sbit S1 = P1^0;
sbit S2 = P1^1;
sbit S3 = P1^2;
sbit S4 = P1^3;
sbit S5 = P1^4;
// 延时函数
void delay_ms(unsigned int t)
{
unsigned int i, j;
for(i = t; i > 0; i--)
for(j = 50; j > 0; j--);
}
// 前进 ------ 大幅降速（通电极短，断电很长）
void forward(void)
{
IN1 = 1; IN2 = 0;
IN3 = 1; IN4 = 0;
delay_ms(4); // 通电时间更短
IN1 = 0; IN2 = 0;
IN3 = 0; IN4 = 0;
delay_ms(20); // 断电时间更长 → 速度极慢
}
// 轻微左转
void left_slow(void)
{
IN1 = 0; IN2 = 0;
IN3 = 1; IN4 = 0;
delay_ms(6);
}
// 轻微右转
void right_slow(void)
{
IN1 = 1; IN2 = 0;
IN3 = 0; IN4 = 0;
delay_ms(6);
}
// 原地左转
void left_spot(void)
{
IN1 = 0; IN2 = 1;
IN3 = 1; IN4 = 0;
delay_ms(2);
}
// 原地右转
void right_spot(void)
{
IN1 = 1; IN2 = 0;
IN3 = 0; IN4 = 1;
delay_ms(2);
}
// 停车
void stop(void)
{
IN1 = 0; IN2 = 0;
IN3 = 0; IN4 = 0;
}
void main(void)
{
stop();
delay_ms(50);
while(1)
{
bit s1 = S1;
bit s2 = S2;
bit s3 = S3;
bit s4 = S4;
bit s5 = S5;
if(s3 == 0)
{
forward();
}
else if(s2 == 0 && s3 == 1)
{
left_slow();
}
else if(s1 == 0 && s2 == 1 && s3 == 1)
{
left_spot();
}
else if(s4 == 0 && s3 == 1)
{
right_slow();
}
else if(s5 == 0 && s4 == 1 && s3 == 1)
{
right_spot();
}
else
{
stop();
delay_ms(20);
left_spot();
right_spot();
}
}
}使用EAEB引脚
#include <REG52.H>
/* ================= ???? IO ?? ================= */
sbit IN1 = P2^0; // ?????1
sbit IN2 = P2^1; // ?????2
sbit IN3 = P2^2; // ?????1
sbit IN4 = P2^3; // ?????2
sbit ENA = P2^4; // ???PWM??
sbit ENB = P2^5; // ???PWM??
/* ================= ????? IO ?? ================= */
sbit Sensor_Left1 = P1^4;
sbit Sensor_Left2 = P1^3;
sbit Sensor_Mid = P1^2;
sbit Sensor_Right1 = P1^1;
sbit Sensor_Right2 = P1^0;
/* ================= ???? ================= */
unsigned char LeftPWM = 0;
unsigned char RightPWM = 0;
unsigned char pwm_count = 0;
signed char last_dir = 0;
/* ================= ???? ================= */
void Timer0_Init(void);
void DelayMs(unsigned int ms);
void Sensor_Read(unsigned char *sensor_data);
void Motor_SetForwardDir(void);
void Motor_SetBackwardDir(void);
void Motor_Stop(void);
void Set_Speed(unsigned char left, unsigned char right);
void Go_Straight(void);
void Turn_Left_Small(void);
void Turn_Left_Mid(void);
void Turn_Left_Big(void);
void Turn_Right_Small(void);
void Turn_Right_Mid(void);
void Turn_Right_Big(void);
void Track_Follow(unsigned char *sensor_data);
/* ================= ?????(????????) ================= */
void DelayMs(unsigned int ms)
{
unsigned int i, j;
for(i = 0; i < ms; i++)
for(j = 0; j < 120; j++);
}
/* ================= ???0???(PWM) ================= */
void Timer0_Init(void)
{
TMOD &= 0xF0;
TMOD |= 0x01;
TH0 = 0xFF;
TL0 = 0x9C;
ET0 = 1;
EA = 1;
TR0 = 1;
}
/* ================= ???0??(??PWM) ================= */
void Timer0_ISR(void) interrupt 1
{
TH0 = 0xFF;
TL0 = 0x9C;
pwm_count++;
if(pwm_count >= 100)
pwm_count = 0;
if(pwm_count < LeftPWM)
ENA = 1;
else
ENA = 0;
if(pwm_count < RightPWM)
ENB = 1;
else
ENB = 0;
}
/* ================= ?????? ================= */
void Motor_SetForwardDir(void)
{
IN1 = 1; IN2 = 0;
IN3 = 1; IN4 = 0;
}
void Motor_SetBackwardDir(void)
{
IN1 = 0; IN2 = 1;
IN3 = 0; IN4 = 1;
}
/* ================= ??PWM??? ================= */
void Set_Speed(unsigned char left, unsigned char right)
{
if(left > 100) left = 100;
if(right > 100) right = 100;
LeftPWM = left;
RightPWM = right;
}
/* ================= ???? ================= */
void Motor_Stop(void)
{
LeftPWM = 0; RightPWM = 0;
ENA = 0; ENB = 0;
IN1 = 0; IN2 = 0; IN3 = 0; IN4 = 0;
}
/* ================= ??????? ================= */
void Sensor_Read(unsigned char *sensor_data)
{
sensor_data[0] = Sensor_Right2;
sensor_data[1] = Sensor_Right1;
sensor_data[2] = Sensor_Mid;
sensor_data[3] = Sensor_Left2;
sensor_data[4] = Sensor_Left1;
}
/* ================= ?????? ================= */
void Go_Straight(void)
{
Motor_SetForwardDir();
Set_Speed(15, 15);
last_dir = 0;
}
void Turn_Left_Small(void)
{
Motor_SetForwardDir();
Set_Speed(10, 20);
last_dir = -1;
}
void Turn_Left_Mid(void)
{
Motor_SetForwardDir();
Set_Speed(5, 25);
last_dir = -1;
}
void Turn_Left_Big(void)
{
// ????,????(????)
IN1 = 0; IN2 = 1;
IN3 = 1; IN4 = 0;
Set_Speed(20, 20);
last_dir = -1;
}
void Turn_Right_Small(void)
{
Motor_SetForwardDir();
Set_Speed(20, 10);
last_dir = 1;
}
void Turn_Right_Mid(void)
{
Motor_SetForwardDir();
Set_Speed(25, 5);
last_dir = 1;
}
void Turn_Right_Big(void)
{
// ????,????(????)
IN1 = 1; IN2 = 0;
IN3 = 0; IN4 = 1;
Set_Speed(20, 20);
last_dir = 1;
}
/* ================= ?????? ================= */
void Track_Follow(unsigned char *sensor_data)
{
unsigned char s1, s2, s3, s4, s5;
s1 = sensor_data[0];
s2 = sensor_data[1];
s3 = sensor_data[2];
s4 = sensor_data[3];
s5 = sensor_data[4];
// ???? -> ??
if(s1==0 && s2==0 && s3==0 && s4==0 && s5==0)
{
Go_Straight();
return;
}
// ??(????)-> ?????????
if(s1==1 && s2==1 && s3==1 && s4==1 && s5==1)
{
if(last_dir < 0)
{
Turn_Left_Big();
Set_Speed(10, 10);
}
else if(last_dir > 0)
{
Turn_Right_Big();
Set_Speed(10, 10);
}
else
{
Go_Straight();
Set_Speed(10, 10);
}
return;
}
// ?????????
if(s3 == 0)
{
if(s2==0 && s4==0) // ???
{
Go_Straight();
return;
}
if(s2==0 && s4==1) // ??
{
Turn_Left_Small();
return;
}
if(s2==1 && s4==0) // ??
{
Turn_Right_Small();
return;
}
Go_Straight();
return;
}
// ??????,???????????
if(s1==0 && s2==0) { Turn_Left_Big(); return; }
if(s2==0) { Turn_Left_Mid(); return; }
if(s4==0 && s5==0) { Turn_Right_Big(); return; }
if(s4==0) { Turn_Right_Mid(); return; }
if(s1==0) { Turn_Left_Big(); return; }
if(s5==0) { Turn_Right_Big(); return; }
Go_Straight();
}
/* ================= ??? ================= */
void main(void)
{
unsigned char sensor[5];
Motor_Stop();
DelayMs(300); // ??????,??
Timer0_Init();
while(1)
{
Sensor_Read(sensor);
Track_Follow(sensor);
// ??????,?????????
}
}上述代码经测试后都能实现循迹，不用封装，直接在主函数中编译再烧录进51单片机后即可
无法循迹的可能原因：左轮与右轮动力不一，会使小车左转时冲出循迹线，进而无法实现循迹（折磨了我一个星期）