int leddelay = 4000;
int redpin = 10;
int yellowpin = 9;
int greenpin = 8;
int ldrpin = A0;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(redpin, OUTPUT);
pinMode(yellowpin, OUTPUT);
pinMode(greenpin, OUTPUT);
pinMode(ldrpin, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  //membaca nilai ldr input analog
int ldrstatus = analogRead(ldrpin);
//pengujian kondisi
if(ldrstatus >=200)
{digitalWrite(yellowpin, HIGH);
delay(350);
digitalWrite(yellowpin, LOW);
delay(350);
Serial.print("mode malam hati hati");
Serial.println(ldrstatus);
}
else
{//lampu bangjo menyala
//lampu merah menyala
digitalWrite(redpin, HIGH);
delay(leddelay);
//lampu kuning hidup beberapa detik
digitalWrite(yellowpin, HIGH);
delay(500);
digitalWrite(redpin, LOW);
//lampu hijaunya nyala
digitalWrite(greenpin, HIGH);
digitalWrite(redpin, LOW);
digitalWrite(yellowpin, LOW);
delay(leddelay);
//lampu kuning menyala
digitalWrite(yellowpin, HIGH);
digitalWrite(greenpin, LOW);
digitalWrite(redpin, LOW);
delay(500);
//lampu kuning mati
digitalWrite(yellowpin, LOW);
//kembali ke program awal
Serial.print("mode sung bangjo aktif");
Serial.println(ldrstatus);
}
}