int led_red = 4;
int led_blue = 5;
int ledState_red = LOW;
int ledState_blue = HIGH;
long previousMillis = 0;
long interval = 1000;
void setup(){
pinMode(led_red, OUTPUT);
pinMode(led_blue, OUTPUT);
}
void loop(){
unsigned long currentMillis = millis();
if(currentMillis - previousMillis > interval){
previousMillis = currentMillis;
if(ledState_red == LOW){
ledState_red = HIGH;
ledState_blue = LOW;
}
else{
ledState_red = LOW;
ledState_blue = HIGH;
}
digitalWrite(led_red, ledState_red);
digitalWrite(led_blue, ledState_blue);
}
}
=============================================================
currentMillis(1초) - previousMillis(0초) 값이 interval(1초)보다 클 때
currentMillis(1초)값을 previousMillis값에 대입하고 다시 연산
또 다시 currentMillis(2초) - previousMillis(1초)값이 interval값(1초)보다 커질 때
currentMillis(2초)값을 previousMillis값에 대입.
