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我正在使用PIC16F877A开发距离传感器。
我正在使用MPLAB IDE 和 XC8编译器。
我的目标是在一定距离水平逐渐打开正确的 LED，但 LED 闪烁不稳定。我究竟做错了什么？distance/5

  • 当它测量 5 厘米时，它是 5/5，结果是1，并且 1 个 LED 亮起。
  • 当它测量 10 厘米时，它是 10/5，结果是2 并且 2 个 LED 亮起。
  • 当您测量 15 厘米时，它是 15/5，结果是3 和 3 个 LED 亮起。
  • 当您测量 20 厘米时，它是 20/5，结果是4 并且 4 个 LED 亮起。
  • 如果距离小于 5 厘米或大于 20 厘米，则没有 LED 灯亮

https://i.stack.imgur.com/fFKQg.png

#include <xc.h>
#include <pic16f877a.h> 
#pragma config FOSC = XT        // Oscillator Selection bits (XT oscillator)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = OFF      // Brown-out Reset Enable bit (BOR disabled)
#pragma config LVP = OFF        // Low-Voltage (Single-Supply) In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming)
#pragma config CPD = OFF        // Data EEPROM Memory Code Protection bit (Data EEPROM code protection off)
#pragma config WRT = OFF        // Flash Program Memory Write Enable bits (Write protection off; all program memory may be written to by EECON control)
#pragma config CP = OFF         // Flash Program Memory Code Protection bit (Code protection off)
#define _XTAL_FREQ 4000000
#define trigger RC2
#define echo RC3

int calc_distance();

int calc_distance()
{
    int distance=0;
     
    trigger=1;
    __delay_us(10);
    trigger=0;
    
    while(!echo); // normally the echo pin is logic 0. If we toggle the zero and throw it into the while, it returns idle until the echo arrives (until the signal becomes logic 1).
    TMR1ON=1;//In the upper loop, while returning the command empty, echo comes and exits the upper loop and timer1 is activated.
    
    while(echo);
    TMR1ON=0;//
 
  distance=TMR1/58;
  return distance;
    
}



void main(void)
{
 
  int dist=0; // Create Distance Variable
  
 
  TRISB = 0x00;  // Set PORTB To Be Output Port (All The 8 Pins)
  
  PORTB = 0x00;  // Set PORTB To Be LOW For initial State
 
  TRISC2 = 0;     // Set RC2 To Be Output Pin ( Trigger )
  RC2 = 0;
  
  TRISC3 = 1;   // Set RC3 To Be Input Pin ( Echo )
  
  //--[ Configure Timer Module To Operate in Timer Mode ]--
  // Clear The Pre-Scaler Select Bits
  T1CKPS0=0;
  T1CKPS1=0;
  
  TMR1CS=0;// Choose The Local Clock As Clock Source
  
  
  while(1)
  {
    calc_distance();
    dist = calc_distance()/5;
    if(dist==1)
    {PORTB = 0x01; __delay_ms(50);}
    if(dist==2)
    {PORTB = 0x03; __delay_ms(50);}
    if(dist==3)
    {PORTB = 0x07; __delay_ms(50);}
    if(dist==4)
    {PORTB = 0x0F; __delay_ms(50);}
    else
    {PORTB = 0x00; __delay_ms(50);}
  }
  return;
}
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