Just in time for Halloween, this Instructable shows how to build a "scene controller" using an Arduino Uno, a motion sensor, some solid state relays, a two gang power outlet, a servo motor and miscellaneous parts. I made this scene controller for Halloween of last year (I didn't have time to publish it last year) but it can be used to control other scenes such as for Christmas.

When the motion sensor detects the kids coming to the front door, the Arduino starts a series of weird sounds, random movement of a "spider" and randomly turning on/off lamps as seen in the video.

**********************************************

WARNING: This project has HIGH VOLTAGE components/connections which may be dangerous. Be extremely careful when building it or you may electrocute yourself! You have been warned!!! **********************************************

Here is the Bill of Materials (BOM):

1 Arduino Uno
1 Solid state relay
1 PIR Motion Sensor
1 Three Gang Electrical Box
1 Duplex Power Outlet
1 Gang Midway 2 Toggle Combination Nylon Wall Plate
2 Blank Insert for Toggle Switch
2 Mounting Brackets - I had these laying (see photos)
1 Long Extension Cord - Use any cord, length and color you want, the link is just an example
1 Short Extension Cord
2 Male Insulated Connectors
2 Female Insulated Connectors
1 Speaker or Buzzer - Anything you can hook up to the Arduino to make sound
1 USB Power Supply - You probably have several of these already
1 Old Pants Hanger
2 Outdoor Lamps
1 Owl LED Lamp - I bought mine at Michaels, it is a seasonal item so it is not available all the time
1 Halloween Garland - Also from Michaels
1 Felt Pumpkin - Also from Michaels
Miscellaneous screws, nuts, connectors, stand-offs and wires.

These parts are for the USA, substitute as appropriate for your country.

This Instructable is a draft, I'll finalize it as it gets closer to Halloween and I actually put everything in place.

Step 1: Extension Cord/Mounting Brackets

In this step we'll start putting the outlet box together.

Here are the sub-steps:

Cut the end of the long extension cord (with the outlets) about 6" (15 cm) from the end.
Attach 1 male and 1 female insulated connector to the extension cord.
Attach 1 male and 1 female insulated connector to the cut end (with the outlets). Make sure the connectors match the connectors on the extension cord.
Push the extension cord through one of the snap-offs on the outlet box and pull it in around 12" (30 cm).
Make a knot in the extension cord so it can't be pulled out.
Connect the cut end (with outlets) to the extension cord.
Attached the two brackets to the outlet box. These are used to attached the complete box to a wall or soffit.

Step 2: Solid State Relays, Outlet, Arduino and Outlet Box

In this step we'll connect the solid state relay and outlet receptacle. Be very careful not to have anything that can short out. The sub-steps is as follows:

Cut out a notch around ¼" (60 mm) square to allow the cables to the outside of the outlet box.
Cut about 12" (30 cm) from the plug of the short extension cord (or make your own short cable with an plug).
Attach the common line of the short extension cord to the outlet receptacle.
Attach the other line of the short extension cord to one of the solid state relays and add a short jumper to the other relay.
Attach a short cable from each solid state relay to each of the receptacles of the outlet.
Attach 4 jumper cables from the relay control. These must be long enough to reach the Arduino which will be mounted on the outside of the outlet box.
Attached the Arduino to the outside of the outlet box.
Attach the solid state relay to the outlet box using some standoffs.
Plug the USB power supply and the short extension cord to the long extension cord.
Carefully place the power supply and cords in the outlet box.
Attach both blank inserts to the outlet box.
Run both the cables for the Arduino and the USB cable through the notch.
Attach the wall plate to the outlet box.

Step 3: The "Spider"

Originally I just wanted something that would move and not be scary to small kids. After I built it and looks at the video, I noticed that it did look somewhat like a spider. Take the old dry clean pants hanger, remove the paper roll and attach the Halloween garland to the hanger. Attach the felt pumpkin to the garland.

Step 4: Schematic

This is the schematic for the scene controller. Connected to the Arduino are the following:

The speaker/buzzer
The servo
The Owl LED Lamp
The PIR Motion Sensor
The dual Solid State Relay (which is connected to the Power Outlet)

You can connect a "regular" lamp or other device to the power outlet.

Step 5: Arduino Code

The Arduino code is available from here.

Or cut-n-paste the the following Arduino code:

// The MIT License (MIT)
//
// Copyright (c) 2015 Aram Perez
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#include <DigitalIO.h> //Download from  https://github.com/aramperez/digital-io

#include <Servo.h>
#include "pitches.h"

#define SERVO_MIN 5
#define SERVO_MAX 155

//
// Pin Definitions
//
#define AC1_PIN 2
#define AC2_PIN 3
#define PIR_PIN 4
#define OWL_PIN 5
#define SERVO_PIN 6
#define SPEAKER_PIN 7

DigitalInput pir(PIR_PIN);
DigitalOutputAL owl(OWL_PIN);
DigitalOutputAH ac1(AC1_PIN);
DigitalOutputAH ac2(AC2_PIN);
Servo servo;

void setup()
{
  Serial.begin(115200);
  randomSeed(analogRead(0));
  servo.attach(SERVO_PIN);
  Serial.println("Setup completed.");
}

void loop()
{
  static bool motionDetected = false;
  static unsigned long  owlStart, owlDuration,
         ac1Start, ac1Duration,
         ac2Start, ac2Duration,
         noteStart, noteDuration,
         servoStart, servoDuration;
  if ( pir.Read() ) {
    delay(200);
    if ( pir.Read() && !motionDetected ) {
      Serial.println("Motion detected!");
      motionDetected = true;
      owlStart = ac1Start = ac2Start = noteStart = servoStart = millis();
      owl.On();
      owlDuration = random(200, 2000);
      ac1.On();
      ac1Duration = random(1000, 2000);
      ac2.On();
      ac2Duration = random(1000, 2000);
      noteDuration = (unsigned long) random(500, 1500);
      tone(SPEAKER_PIN, random(NOTE_B0, NOTE_DS8 + 1));
      servoDuration = random(SERVO_MIN, SERVO_MAX);
      servo.write(random(5, 170));
    }
  } else {
    delay(200);
    if ( !pir.Read() && motionDetected ) {
      Serial.println("Motion ended!");
      motionDetected = false;
      noTone(SPEAKER_PIN);
      owl.Off();
      ac1.Off();
      ac2.Off();
    }
  }
  if ( motionDetected ) {
    int currentMillis = millis();
    if ( currentMillis - owlStart > owlDuration ) {
      owlStart = currentMillis;
      owlDuration = random(100, 500);
      owl.Toggle();
    }
    if ( currentMillis - ac1Start > ac1Duration ) {
      ac1Start = currentMillis;
      ac1Duration = random(500, 1000);
      ac1.Toggle();
    }
    if ( currentMillis - ac2Start > ac2Duration ) {
      ac2Start = currentMillis;
      ac2Duration = random(500, 1000);
      ac2.Toggle();
    }
    if ( currentMillis - noteStart > noteDuration ) {
      noteStart = currentMillis;
      noteDuration = (unsigned long) random(300, 1200);
      tone(SPEAKER_PIN, random(NOTE_B0, NOTE_DS8 + 1));
    }
    if ( currentMillis - servoStart > servoDuration ) {
      servoStart = currentMillis;
      servoDuration = random(300, 500);
      servo.write(random(SERVO_MIN, SERVO_MAX));
    }
  }
}

Here's the "pitches.h" file:

/*************************************************
 * Public Constants
 * This file is from Tone Tutorial at  https://www.arduino.cc/en/Tutorial/Tone

 *************************************************/

#define NOTE_B0  31
#define NOTE_C1  33
#define NOTE_CS1 35
#define NOTE_D1  37
#define NOTE_DS1 39
#define NOTE_E1  41
#define NOTE_F1  44
#define NOTE_FS1 46
#define NOTE_G1  49
#define NOTE_GS1 52
#define NOTE_A1  55
#define NOTE_AS1 58
#define NOTE_B1  62
#define NOTE_C2  65
#define NOTE_CS2 69
#define NOTE_D2  73
#define NOTE_DS2 78
#define NOTE_E2  82
#define NOTE_F2  87
#define NOTE_FS2 93
#define NOTE_G2  98
#define NOTE_GS2 104
#define NOTE_A2  110
#define NOTE_AS2 117
#define NOTE_B2  123
#define NOTE_C3  131
#define NOTE_CS3 139
#define NOTE_D3  147
#define NOTE_DS3 156
#define NOTE_E3  165
#define NOTE_F3  175
#define NOTE_FS3 185
#define NOTE_G3  196
#define NOTE_GS3 208
#define NOTE_A3  220
#define NOTE_AS3 233
#define NOTE_B3  247
#define NOTE_C4  262
#define NOTE_CS4 277
#define NOTE_D4  294
#define NOTE_DS4 311
#define NOTE_E4  330
#define NOTE_F4  349
#define NOTE_FS4 370
#define NOTE_G4  392
#define NOTE_GS4 415
#define NOTE_A4  440
#define NOTE_AS4 466
#define NOTE_B4  494
#define NOTE_C5  523
#define NOTE_CS5 554
#define NOTE_D5  587
#define NOTE_DS5 622
#define NOTE_E5  659
#define NOTE_F5  698
#define NOTE_FS5 740
#define NOTE_G5  784
#define NOTE_GS5 831
#define NOTE_A5  880
#define NOTE_AS5 932
#define NOTE_B5  988
#define NOTE_C6  1047
#define NOTE_CS6 1109
#define NOTE_D6  1175
#define NOTE_DS6 1245
#define NOTE_E6  1319
#define NOTE_F6  1397
#define NOTE_FS6 1480
#define NOTE_G6  1568
#define NOTE_GS6 1661
#define NOTE_A6  1760
#define NOTE_AS6 1865
#define NOTE_B6  1976
#define NOTE_C7  2093
#define NOTE_CS7 2217
#define NOTE_D7  2349
#define NOTE_DS7 2489
#define NOTE_E7  2637
#define NOTE_F7  2794
#define NOTE_FS7 2960
#define NOTE_G7  3136
#define NOTE_GS7 3322
#define NOTE_A7  3520
#define NOTE_AS7 3729
#define NOTE_B7  3951
#define NOTE_C8  4186
#define NOTE_CS8 4435
#define NOTE_D8  4699
#define NOTE_DS8 4978

Step 6: Mounting

Once you have programmed the Arduino, you should mount the outlet box to the soffit near your front door so it is out of sight and protected from water (in case it rains). Plug in the lamps (or whatever else is powered by the mains). Mount the servo and the hanging spider to the soffit. Attach some sort of string to both the servo and spider. the Finally, mount the PIR motion sensor so it points towards the street so that when the kids start walking towards your front door, the action starts. Sit back and enjoy the fun as you hand out candy to the kids!