4. Hướng dẫn lập trình

#include <Wire.h> #include <LiquidCrystal_I2C.h>

#define TRIGPIN 9 #define ECHOPIN 10

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {

lcd.init(); lcd.backlight(); pinMode(TRIGPIN, OUTPUT); pinMode(ECHOPIN, INPUT);

} void loop() {

long duration, distance;

digitalWrite(TRIGPIN, LOW); delayMicroseconds(2); digitalWrite(TRIGPIN, HIGH); delayMicroseconds(10); digitalWrite(TRIGPIN, LOW);

duration = pulseIn(ECHOPIN, HIGH); distance = duration * 0.034 / 2;

lcd.clear(); lcd.setCursor(0, 0); lcd.print("Distance: "); lcd.print(distance); lcd.print(" cm");

delay(2000);

}