我有一张图片 18F4550 如何读取超声波传感器的距离

Question

我有 PIC 18f4550，需要在 picBasic pro 中编写代码。
我正在连接直流电机、超声波传感器和红外传感器...等等
我已经完成了所有工作，但仍然对如何连接超声波传感器感到困惑。

这是PIC中的超声波引脚

trisb.3=0    'trigger ultrasound
trisb.4=1    ' Echo from Ultrasound

我需要一个示例代码

Answer 1

编程的基本步骤：

1-提供TRIGGER给超声波模块
2-听回声
3-收到 ECHO HIGH 时启动定时器
ECHO 变低时的 4 停止计时器
5 读定时器值
6-将其转换为距离
7-显示它

距离计算

距离=速度*时间
令 d 为超声波传感器与目标之间的距离
超声波脉冲移动的总距离：2d（向前和向后）
空气中的声速：340 m/s = 34000 cm/s
因此，d = (34000*Time)/2，其中 Time = (TMR1H:TMR1L)/(1000000)
因此，d = (TMR1H:TMR1L)/58.82 cm
TMR1H:TMR1L = TMR1L | (TMR1H<<8)

MikroC 代码

// LCD module connections
sbit LCD_RS at RD2_bit;
sbit LCD_EN at RD3_bit;
sbit LCD_D4 at RD4_bit;
sbit LCD_D5 at RD5_bit;
sbit LCD_D6 at RD6_bit;
sbit LCD_D7 at RD7_bit;

sbit LCD_RS_Direction at TRISD2_bit;
sbit LCD_EN_Direction at TRISD3_bit;
sbit LCD_D4_Direction at TRISD4_bit;
sbit LCD_D5_Direction at TRISD5_bit;
sbit LCD_D6_Direction at TRISD6_bit;
sbit LCD_D7_Direction at TRISD7_bit;
// End LCD module connections

void main()
{
  int a;
  char txt[7];
  Lcd_Init();
  Lcd_Cmd(_LCD_CLEAR);          // Clear display
  Lcd_Cmd(_LCD_CURSOR_OFF);     // Cursor off

  TRISB = 0b00010000;           //RB4 as Input PIN (ECHO)

  Lcd_Out(1,1,"Developed By");
  Lcd_Out(2,1,"Mina Karam");

  Delay_ms(3000);
  Lcd_Cmd(_LCD_CLEAR);

  T1CON = 0x10;                 //Initialize Timer Module

  while(1)
  {
    TMR1H = 0;                  //Sets the Initial Value of Timer
    TMR1L = 0;                  //Sets the Initial Value of Timer

    PORTB.F0 = 1;               //TRIGGER HIGH
    Delay_us(10);               //10uS Delay
    PORTB.F0 = 0;               //TRIGGER LOW

    while(!PORTB.F4);           //Waiting for Echo
    T1CON.F0 = 1;               //Timer Starts
    while(PORTB.F4);            //Waiting for Echo goes LOW
    T1CON.F0 = 0;               //Timer Stops

    a = (TMR1L | (TMR1H<<8));   //Reads Timer Value
    a = a/58.82;                //Converts Time to Distance
    a = a + 1;                  //Distance Calibration
    if(a>=2 && a<=400)          //Check whether the result is valid or not
    {
      IntToStr(a,txt);
      Ltrim(txt);
      Lcd_Cmd(_LCD_CLEAR);
      Lcd_Out(1,1,"Distance = ");
      Lcd_Out(1,12,txt);
      Lcd_Out(1,15,"cm");
    }
    else
    {
      Lcd_Cmd(_LCD_CLEAR);
      Lcd_Out(1,1,"Out of Range");
    }
    Delay_ms(400);
  }
}

我有一张图片 18F4550 如何读取超声波传感器的距离

I have a pic 18F4550 how to read distance from ultrasonic sensor

visual-studio

embedded

microcontroller

sensors

pic

编程的基本步骤：

距离计算