#define buttonpin D3
#define relay D0

int buttonspace=0;

void setup() {
  pinMode(buttonpin,INPUT);
  pinMode(relay,OUTPUT);
  Serial.begin(9600);
}

void loop() {
  buttonstate=digitalRead(buttonpin);
  Serial.print("buttonstate status is:");
  serial.println(buttonstate);

  if(buttonstate==HIGH);
  digitalWrite(relay,HIGH);

  else
  digitalWrite(relay,LOW);
  delay(500);

}