Re-enables interrupts (after they've been disabled by noInterrupts()). Interrupts allow certain important tasks to happen in the background and are enabled by default. Some functions will not work while interrupts are disabled, and incoming communication may be ignored. Interrupts can slightly disrupt the timing of code, however, and may be disabled for particularly critical sections of code.


void setup() {}

void loop()
  noInterrupts(); // disable interrupts
  // put critical, time-sensitive code here
  interrupts();   // enable interrupts
  // other code here

interrupts() neither accepts a parameter nor returns anything.