Remote control light switch (IR on 12, servo on 11), on an Arduino Uno

// A remote control for a light switch: a servo arm presses it for you.
//
//   IR receiver OUT -> pin 12   VCC -> 5V   GND -> GND
//   servo signal    -> pin 11   servo + -> 5V   servo - -> GND
//
// Tape the servo beside an ordinary wall switch so its arm can push the
// switch up or down. Then the remote works the light without any change to
// the house wiring.
//
// Button 1 swings the arm to 150 degrees (on), button 2 to 30 degrees (off),
// and after each push the arm comes back to the middle so the switch can
// still be used by hand.

#include <IRremote.hpp>
#include <Servo.h>

const int RECEIVER_PIN = 12;
const int SERVO_PIN = 11;
const int MIDDLE = 90;

Servo arm;

void push(int angle, const char *what) {
  arm.write(angle);
  Serial.println(what);
  delay(500);
  arm.write(MIDDLE);
}

void setup() {
  Serial.begin(9600);
  IrReceiver.begin(RECEIVER_PIN, ENABLE_LED_FEEDBACK);
  arm.attach(SERVO_PIN);
  arm.write(MIDDLE);
  Serial.println("Mokxi Uno: remote light switch. Press 1 for on, 2 for off.");
}

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;
  if (command == 0x0C) {
    push(150, "1: switch on");
  } else if (command == 0x18) {
    push(30, "2: switch off");
  } else {
    Serial.print("button 0x");
    Serial.print(command, HEX);
    Serial.println(" does nothing here");
  }
}