Use blynk button as an interrupt to the sensors

[Gunner]

I fixed your posted code as per the requirements shown in the Welcome Topic

[README] Welcome to Blynk Community!

Hey, welcome to Blynk Community. This is the best place to ask questions, leave feedback and share your ideas. If this is the first time you hear about Blynk, check out our website www.blynk.cc and come back! As the community is big (and growing), let’s agree on some basic rules. Asking for help Before creating a new topic and asking for help, please check if your question was already answered: Use forum search function You may want to check out: Blynk Documentation Blynk Wiki Blynk Exa…

@Syafiq_Khairil_Anuar

int value_ldr = digitalRead(ldr_pin);
Serial.println(value_ldr);
if(value_ldr==HIGH){ digitalWrite(relay_pin,HIGH);
digitalWrite(lamp,HIGH); delay(10);
} else { digitalWrite(relay_pin,LOW);
digitalWrite(lamp,LOW);
}

Keep all this out of the void loop() and into its own timed function…

http://help.blynk.cc/getting-started-library-auth-token-code-examples/blynk-basics/keep-your-void-loop-clean

Learn about BlynkTimer…

http://help.blynk.cc/getting-started-library-auth-token-code-examples/blynk-basics/how-to-display-any-sensor-data-in-blynk-app