Remote dimmer: IR on 12, LED on 5, buzzer on 13, on an Arduino Uno

// A remote dimmer: buttons 0 to 3 set the LED's brightness.
//
//   receiver OUT -> pin 12   VCC -> 5V   GND -> GND
//   pin 5 -> 220 ohm -> LED -> GND
//   pin 13 -> 1k -> an NPN transistor's base; the active buzzer from 5V
//   to its collector; emitter -> GND
//
// Each NEC command is one button: 0x16 is 0, 0x0C is 1, 0x18 is 2 and 0x5E
// is 3. The buzzer clicks for every code, so you can hear that it arrived.
//
// Press 0, 1, 2 or 3 on the remote.

// The simulated remote speaks NEC, so only that decoder is compiled in.
#define DECODE_NEC
#include <IRremote.hpp>

const int RECEIVER = 12;
const int LED_PIN = 5;
const int BUZZER = 13;

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  Serial.begin(9600);
  IrReceiver.begin(RECEIVER, ENABLE_LED_FEEDBACK);
  Serial.println("UNO is ready! Press 0, 1, 2 or 3.");
}

void loop() {
  if (!IrReceiver.decode()) return;
  bool repeat = IrReceiver.decodedIRData.flags & IRDATA_FLAGS_IS_REPEAT;
  uint8_t command = IrReceiver.decodedIRData.command;
  IrReceiver.resume();
  if (repeat) return;
  Serial.println(command, HEX);
  digitalWrite(BUZZER, HIGH);
  delay(100);
  digitalWrite(BUZZER, LOW);
  switch (command) {
    case 0x16: analogWrite(LED_PIN, 0); break;
    case 0x0C: analogWrite(LED_PIN, 7); break;
    case 0x18: analogWrite(LED_PIN, 63); break;
    case 0x5E: analogWrite(LED_PIN, 255); break;
  }
}