04.超音波測距尺(1)

1.超音波SENSOR 連接如圖

2. LCD 連接如圖

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

#define Trig 4        

#define Echo 5     

LiquidCrystal_I2C lcd(0x3F,16,2);

float   Temp=30  ; 

void setup() {

  Serial.begin(9600);                                                   

  lcd.init();                     

  lcd.backlight(); 

  pinMode(Trig, OUTPUT);

}

void loop() {

digitalWrite(Trig, LOW);

delayMicroseconds(2);

digitalWrite(Trig, HIGH); delayMicroseconds(10);

digitalWrite(Trig, LOW);

double  t = pulseIn(Echo, HIGH,50000);

double dist = (331+0.6*Temp)*t/20000 ; 

if(dist>3&&dist<500){

lcd.setCursor(0,0);

lcd.print(dist);

lcd.print("cm");

lcd.print("         ");

}else{

lcd.setCursor(0,0);

lcd.print("Out of Range...");

}

delay(100);

}