loop()

1int buttonPin = 3;
2
3    // setup initializes serial and the button pin
4    void setup() {
5      Serial.begin(9600);
6      pinMode(buttonPin, INPUT);
7    }
8
9    // loop checks the button pin each time,
10    // and will send serial if it is pressed
11    void loop() {
12      if (digitalRead(buttonPin) == HIGH) {
13        Serial.write('H');
14      }
15      else {
16        Serial.write('L');
17      }
18
19      delay(1000);
20    }