Master Code

#define buttonPin 7
int state = 0;

void setup()
{
 pinMode(buttonPin, INPUT);
 Serial.begin(115200);
}

void loop()
{
  delay(15000);
  Serial.print("Serial Value Sent: ");
  Serial.println(state);
  state=1;
  delay(15000);
  Serial.print("Serial Value Sent: ");
  Serial.println(state);
  state=0;
}