งานปฏิบัติ 13

Code 1

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);

int triggerPin = 13;

int echoPin = 12;

long duration,distCM,temp_distCM=0;

void setup() 

{

  lcd.begin();

  lcd.setCursor(0,0);

  lcd.print("Dist =      cm");

  pinMode(triggerPin,OUTPUT);

  pinMode(echoPin,INPUT);

}

void loop() 

{

  digitalWrite(triggerPin,LOW);

  delayMicroseconds(2);

  digitalWrite(triggerPin,HIGH);

  delayMicroseconds(10);

  digitalWrite(triggerPin,LOW);

  duration = pulseIn(echoPin,HIGH);

  distCM = duration/58;

  if (temp_distCM != distCM)

  {

    lcd.setCursor(7,0);

    lcd.print("    ");

  }

  lcd.setCursor(7,0);

  lcd.print(distCM);

  temp_distCM = distCM;

  delay(300);

}

Code 2

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);

int triggerPin = 13;

int echoPin = 12;

long duration,distCM;

void setup() 

{

  lcd.begin();

  pinMode(triggerPin,OUTPUT);

  pinMode(echoPin,INPUT);

}

void loop() 

{

  digitalWrite(triggerPin,LOW);

  delayMicroseconds(2);

  digitalWrite(triggerPin,HIGH);

  delayMicroseconds(10);

  digitalWrite(triggerPin,LOW);

  duration = pulseIn(echoPin,HIGH);

  distCM = duration/58;

  int x = constrain(distCM,4,19);

  lcd.clear();

  lcd.home();

  for (int i=4;i<=x;i++)

      lcd.print("*");

  delay(150);

}