งานปฏิบัติที่ 13

wiring diagram

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);
}

Code 3

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
int triggerPin = 13;
int echoPin = 12;
int buzzerpin = 11;
long duration,distCM;
void setup()
{
  lcd.begin();
  pinMode(buzzerpin,OUTPUT);
  pinMode(triggerPin,OUTPUT);
  pinMode(echoPin,INPUT);
  digitalWrite(buzzerpin,HIGH);
}
void loop()
{
  digitalWrite(triggerPin,LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin,HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin,LOW);
  duration = pulseIn(echoPin,HIGH);
  distCM = duration/58;
  lcd.home();
    if (distCM > 400)
  { 
    lcd.clear();
    lcd.print("**!!!Alarm!!!**");
    tone(buzzerpin,700,500);
    delay(500);
    digitalWrite(buzzerpin,HIGH);
    delay(70);
    lcd.setCursor(0,1);
    lcd.print(distCM); 
  }
  else
  {
    lcd.print("<-------------->");
    lcd.setCursor(0,1);
    lcd.print(distCM);
  }
}

Code 4 

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);

int triggerPin = 13;

int echoPin = 12;

int buzzerpin = 11;

long duration,distCM;

void setup() 

{

  lcd.begin();

  pinMode(buzzerpin,OUTPUT);

  pinMode(triggerPin,OUTPUT);

  pinMode(echoPin,INPUT);

  digitalWrite(buzzerpin,HIGH);

}

void loop() 

{

  digitalWrite(triggerPin,LOW);

  delayMicroseconds(2);

  digitalWrite(triggerPin,HIGH);

  delayMicroseconds(10);

  digitalWrite(triggerPin,LOW);

  duration = pulseIn(echoPin,HIGH);

  distCM = duration/58;

  lcd.home();

  if ((distCM>=4)&&(distCM<=30))

  {    

    lcd.clear();

    lcd.print("#####Alarm#####");

    int dl = distCM*20;

    tone(buzzerpin,600,dl);

    delay(dl);

    digitalWrite(buzzerpin,HIGH);

    delay(70);    

  }

  else

  {

    lcd.print("  Dist > 30 cm  ");

  }

}