int sp=7;
int led=8;
int a;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(sp, INPUT);
  pinMode(led, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  a=digitalRead(sp);
  Serial.println(a);
  if(a==1){
    digitalWrite(led, HIGH);
  }
  else{
    digitalWrite(led, LOW);
  }
}