int rele = 6; int led = 4; void setup() { // put your setup code here, to run once: pinMode(rele,INPUT); pinMode(led, OUTPUT); Serial.begin(9600); digitalWrite(led,LOW); } void loop() { // put your main code here, to run repeatedly: Serial.println(digitalRead(rele)); if(digitalRead(rele)== 1){ digitalWrite(led,HIGH); } delay(500); digitalWrite(led,LOW); }