Keyboard

// EXAMPLE USAGE
// Use STARTUP() macro to avoid USB disconnect/reconnect (see begin() documentation)
STARTUP(Keyboard.begin());

void setup() {
  // Type 'SHIFT+h', 'e', 'l', 'l', 'o', 'SPACE', 'w', 'o', 'r', 'l', 'd', 'ENTER'
  Keyboard.println("Hello world!");

  // Type 'SHIFT+t', 'e', 's', 't', 'SPACE', '1', '2', '3', '.', '4', '0', 'ENTER'
  Keyboard.printf("%s %.2f\n", "Test", 123.4f);

  // Quickly press and release Ctrl-Alt-Delete
  Keyboard.click(KEY_DELETE, MOD_LCTRL | MOD_LALT);

  // Press Ctrl, then Alt, then Delete and release them all
  Keyboard.press(KEY_LCTRL);
  Keyboard.press(KEY_LALT);
  Keyboard.press(KEY_DELETE);
  Keyboard.releaseAll();
}

void loop() {
}

Since 0.6.0:

This object allows your device to act as a native USB HID Keyboard.

Keyboard and Mouse support is only available on some devices and Device OS versions: