电子科技大学现代电子系统综合实验小车工程文件代码

/* 功能：超声波测距实验。 功能模块：HC-SR04，测距范围：2cm to 450cm 数码管显示：xxx.x，单位：cm 计算公式如下： s = v*t/2 = (340m/s)*t(s)/2 = (340um/us)*t(us)/2 = (0.34mm/us)*t(us)/2 = (0.034cm/us)*t(us)/2;; s(cm) = t(us)*0.017(cm/us). t is the received Echo high level time from the UltracsonicModule HC-SR04, it messured by T0 timer, t=(12/11.0592)us*(TH0,TL0), initial (TH0,TL0)=0x00 00 s(cm) =0.0184*(TH0,TL0), (TH0,TL0)max = 24456 for s =450cm UltracsonicModule HC-SR04 VCC(+5V) connect to VCC; Gnd connct to GND; Trig connect to P3.3; Echo connect to P3.2. 超声波测距范例 数码管显示测距次数（小于255次，超出从0继续计数）和测距结果（单位：cm） 编制：电子科技大学实验中心2022年6月 */ #include <PCF8591.h> #include <reg52.h> sbit LED1 = P1^0; //定义LED1由P1.0控制 //定义I/O接口 sbit PWM_IN1 = P1^4; // 高电平1：左电机后退（反转） sbit PWM_IN2 = P1^5; // 高电平1：左电机前进（正转） sbit PWM_IN3 = P1^6; // 高电平1：右电机前进（正转） sbit PWM_IN4 = P1^7; // 高电平1：右电机后退（反转） bit show_flag = 0; sbit PWM_EN1 = P1^2; // 高电平1：使能左电机 sbit PWM_EN2 = P1^3; // 高电平1：使能右电机 bit timer_start_flag= 0 ; bit timer_start_flag2 = 0 ; bit start_flag = 1; bit count_flag = 1; #define SPEED_MAX 20 //定义PWM级数，分为0～SPEED_MAX-1级 unsigned int Speed_L ; unsigned int Speed_R ; unsigned char c = 40; //定义计数值变量的初始值 //定义驱动引脚 sbit Echo = P3^2; //Echo sbit Trig = P3^3; //Trig //智能小车数码管按键电路管脚定义 sbit KEY1 = P3^4; //定义按键1，'+'按键，对应核心板上K1 sbit KEY2 = P3^5; //定义按键2，'-'按键，对应核心板上K2 #define LED_seg P0 //8位数码管的段码和位码驱动通过P0端口锁存 #define LED_dig P0 unsigned int distance = 125; //定义显示缓冲区（由定时中断程序自动扫描） unsigned char DispBuf[8]; sbit BUZZER = P2^3; //有源蜂鸣器驱动端口，低电平输出响 //智能小车数码管显示电路管脚定义 sbit SS = P2^6; //数码管段选信号 sbit CS = P2^7; //数码管位选信号 unsigned char sec = 0; //100ms计数 unsigned char sec1 = 0; bit Counter_overflag = 0; //T0定时器溢出标志 bit Echo_Over = 0; //超声波测距完成标志，无论收到回波或没有收到，总要置位一次 unsigned char cnt = 0; //测量次数，每次加一 unsigned int Range = 0; unsigned int Range1 = 0; unsigned int Range2 = 0; unsigned int Range3 = 0; unsigned long Echo_time = 0; //T0定时器合并数值 unsigned int count_flag2 = 0; unsigned int count_flag3 = 0; bit fff = 0; code unsigned char Tab[] = {//定义0123456789AbCdEF的数码管字型数据，其他显示字符需自行计算，如‘-’的字形数据为0x40 0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07, 0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71 }; //============================// /* 函数：Delay() 功能：延时 说明： 晶振频率为11.0592MHz 延时长度 = 1ms * t */ void Delay(unsigned int t) { unsigned int us_ct; for (;t > 0;t --) //执行代码消耗CPU时间 for (us_ct = 113;us_ct > 0;us_ct --); } /* 函数：EX0INTSVC() 功能：外部中断0中断服务程序 用途：为避免定时中断干扰测距的准确性，采用外部中断触发后立即停止计时 外部中断0优先级高于定时中断，程序尽量短，避免过多干扰定时中断 */ void EX0INTSVC() interrupt 0 { TR0 = 0; //停止计时 Echo_time = TH0 * 256 + TL0; //读取定时器0计数值 TH0 = 0; //清除定时器0计数寄存器，为下次计数做准备 TL0 = 0; Echo_Over = 1; //表示本次超声波测距完成，可以启动下次的测量 EX0 = 0; //关闭外部中断，否则会马上引起下一次中断 } //============================// /* 函数：T0INTSVC() 功能：定时器T0的中断服务函数 用途：若超过测距范围，长时间无法收到回波， 已经启动的T0中断会计数溢出，利用定时器溢出标志来判断 */ void T0INTSVC() interrupt 1 { TR0 = 0; //停止计时 Counter_overflag = 1; //中断溢出标志，未收到回波 Echo_Over = 1; //表示本次超声波测距完成，可以启动下次的测量 EX0 = 0; //关闭外部中断 } /* 函数：T1INTSVC() 功能：定时器T1的中断服务函数 */ void T1INTSVC() interrupt 3 //定时器1的中断号为：3 { code unsigned char com[] = {0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01}; //显示位的端口控制字节 static unsigned char n = 0; //n: 扫描显示位计数,0-7 static unsigned int counter_1ms = 0; //1ms计� static unsigned int counter_1ms2 = 0; //1ms计� static unsigned int t = 0; unsigned int x = 0; unsigned int y = 0; //================数码管定时扫描驱动显示=============== TR1 = 0; TH1 = 0xFC; TL1 = 0x66; //可以将FC66换成0000，降低扫描速度，观察和理解动态扫描 TR1 = 1; P0 = 0xFF; //消隐 CS = 1; CS = 0; P0 = DispBuf[n]; //更新扫描显示数据 SS = 1; SS = 0; P0 = ~com[n]; //重新显示 CS = 1; CS = 0; n++; //指向下一位扫描显示 n &= 0x07; //==================================================== t++; if ( t >= SPEED_MAX ) { t = 0; //PWM波的周期为：SPEED_MAX*1ms = 20ms } if(Range >= distance) { x = Range - distance; y=0; } else{ y = Range - distance; x= 1300; } if(start_flag == 0) { if(x >= 300 && x <= 1200){ Speed_L = 4; Speed_R = 5 ; if ( t < Speed_L ) //PWM波高电平时间：(Speed_L)*1ms { PWM_IN1 = 0; PWM_IN2 = 1; //左电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_L）*1ms { PWM_IN1 = 0; PWM_IN2 = 0; //左电机的停转 } if ( t < Speed_R ) //PWM波高电平时间：Speed_R*1ms { PWM_IN3 = 1; PWM_IN4 = 0; //右电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_R）*1ms { PWM_IN3 = 0; PWM_IN4 = 0; //右电机的停转 } } if(x <= 300){ count_flag3 ++; if(count_flag3 == 3) { count_flag3 = 0; Speed_L = 2 ; Speed_R = 3 ; if ( t < Speed_L ) //PWM波高电平时间：(Speed_L)*1ms { PWM_IN1 = 0; PWM_IN2 = 1; //左电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_L）*1ms { PWM_IN1 = 0; PWM_IN2 = 0; //左电机的停转 } if ( t < Speed_R ) //PWM波高电平时间：Speed_R*1ms { PWM_IN3 = 1; PWM_IN4 = 0; //右电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_R）*1ms { PWM_IN3 = 0; PWM_IN4 = 0; //右电机的停转 } } } if( x <= 5){ if(count_flag) { count_flag = 0; sec1 = sec; show_flag = 1; } Speed_L = 0; Speed_R = 0; if ( t < Speed_L ) //PWM波高电平时间：(Speed_L)*1ms { PWM_IN1 = 0; PWM_IN2 = 1; //左电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_L）*1ms { PWM_IN1 = 0; PWM_IN2 = 0; //左电机的停转 } if ( t < Speed_R ) //PWM波高电平时间：Speed_R*1ms { PWM_IN3 = 1; PWM_IN4 = 0; //右电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_R）*1ms { PWM_IN3 = 0; PWM_IN4 = 0; //右电机的停转 } } if( y >= 5){ count_flag2 ++; if(count_flag2 == 3) { Speed_L = 3; Speed_R = 3; count_flag2 = 0; if ( t < Speed_L ) //PWM波高电平时间：(Speed_L)*1ms { PWM_IN1 = 1; PWM_IN2 = 0; //左电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_L）*1ms { PWM_IN1 = 0; PWM_IN2 = 0; //左电机的停转 } if ( t < Speed_R ) //PWM波高电平时间：Speed_R*1ms { PWM_IN3 = 0; PWM_IN4 = 1; //右电机的正转 } else //PWM波低电平时间：（SPEED_MAX-Speed_R）*1ms { PWM_IN3 = 0; PWM_IN4 = 0; //右电机的停转