The sketch shape in Arduino

Blink: the hello world of hardware, in two functions.

// Every sketch is two functions: setup runs once, loop forever.
void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);
  digitalWrite(LED_BUILTIN, LOW);
  delay(500);
}

How it works

1. setup() runs once at power-on; loop() repeats forever.
2. pinMode claims the pin; digitalWrite drives it HIGH and LOW.
3. delay(500) holds each state for half a second.

Keywords and builtins used here

• HIGH
• LED_BUILTIN
• LOW
• OUTPUT
• delay
• digitalWrite
• loop
• pinMode
• setup
• void

The run, in numbers

Lines

11

Characters to type

217

Tokens

44

Three-star pace

75 tpm

At the three-star pace of 75 tokens a minute, this run takes about 35 seconds.

Type this snippet

Step 1 of 3 in The sketch, step 1 of 27 in Language basics.

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