Halloween Scare

Introduction

Halloween is coming up and it's time to do some pranks.  

Everyone likes Halloween and I'm no exception. Every year me and my 

wife decorate the house with lot's of bugs, spider webs, creepy posters 

and of course lot's of Halloween candy.

While making the normal Halloween preparations I came up 

with the idea of making a circuit that would make some scary 

noises and also would react to movement.  

I expect to get some screams and laughs from friends that come 

to visit us this year.  

The circuit is basically a sound chip that records and stores sounds 

in memory and plays them back with a microcontroller and it's 

triggered by light and motion.

The sound chip is from maker winbond and has a very good sound 

quality. 

Schematic

Parts List

R1                   10K ohms resistor
R2                   1K ohms resistor
R3                   100K ohms resistor

R4                   5K1 ohms resistor
R5                   470K ohms resistor
R6                   10K ohms resistor
R7                   10K ohms resistor
R8                   1K ohms resistor
LDR                Light dependent resistor
C1                   100nF capacitor
C2                   100nF capacitor
C3                   100nF capacitor
C4                   100nF capacitor
C5                   10uF capacitor
C6                   22uF capacitor
C7                   220uF capacitor
C8                   4.7uF capacitor
SENSOR        GP2D12 from Sharp
IC1                  12F683 microcontroller from Microchip
IC2                  ISD 2532 from winbond
S1                    Push button
SP                    Speaker
MIC                Electret microphone 
Others:
Box
PCB
Jumpers
4.8V Battery Pack
Hex program for the microcontroller

PCB

The PCB used for this Project is double layer and its size is 

80.66 mm x 47.70 mm.

Top Side

Here is the top side

Bottom Side

Here's the bottom side.

How it works:

This circuit has 2 sensors. One motion sensor ( Sharp GP2D12 ) 

and a light sensor ( LDR ). The microcontroller monitors both 

sensors and triggers the sound chip in certain conditions.

Every time the circuit is powered on, the microcontroller stores 

the distance read by the sharp sensor and uses this as reference 

for the space available for object/people detection. Anything 

moving in front of the sensor up to that reference activates the 

first stored sound.

The other 3 sounds are time triggered only when the light is out. 

The LDR senses the light intensity and only when placed in darkness 

it will activate the remaining sounds. Sometimes the sounds are 

individually played and sometimes combined. There are 4 sounds 

slots available with max. length of 6 seconds each.

How to record sounds:

The PCB has some connectors with jumpers making it possible to 

change from record to playback mode and vice versa.

Connector #1 named REC/PLAY is a 3 pin connector and jumper 

connection must be placed to the left side for record mode or to 

the right side for playback mode.

Also connector #2 named Jumpers must have 2 jumpers installed 

for playback mode. This is responsible for the memory address of the 

sounds.

When in record mode, some wire jumper connections must be made 

to change the address of the recordings manually connecting pin 

2 and 3 to VDD or VSS according to table bellow:

For VDD and VSS connections it's possible to 

use connector named + -

Recording: With power off, connect a microphone, move jumper 

to record mode and connect message pin 2 and pin 3 to VSS.

Turn on the power and prepare the sound you wish to record for #1 sound.
Press and keep the S1 push button while recording. Release the button 

to stop recording.
Connect pin 2 to VDD and keep pin 3 to VSS - this will address sound #2.
Press and keep the S1 push button while recording. Release the button 

to stop recording.
Connect pin 2 to VSS and pin 3 to VDD - this will address sound #3.
Press and keep the S1 push button while recording. Release the button 

to stop recording.
Connect pin 2 to VDD and keep pin 3 to VDD - this will address sound #4.
Press and keep the S1 push button while recording. Release the button 

to stop recording.
Turn the power off, disconnect microphone, restore address jumpers 

and move jumper to playback mode. 

Hex Program

The Hex program named HSCARE.HEX must be saved in the 12F683 

microcontroller's memory before soldering on the PCB.

Assembly and testing

After soldering all components on the PCB and once all sounds are 

recorded it's time to get it inside a box. I've found the perfect box 

for this project... this skull.

Placing the motion sensor in the eye section.

The sharp sensor adds a crazy eyes look to this skull.

The skull is ready to make some noise and scare the visitors.

Conclusion

This is a very cool Halloween project. It's possible to record personalized 

sounds making this even more interesting. I bet that this project will 

bring many screams and laughs. 

Downloads

 Download this project in .DOC format