HackSpace_-_October_2019

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internals with an Amazon Echo, an Arduino, and a

speaker. He also placed an Adafruit Motor Shield inside

the skull and connected it to the skull motor. The

contraption was programmed to turn the motor and

move the jaws of the skull. The whole animation,

audio, and jaw movement were triggered by the skull’s

original motion sensor.

MAKE THEM JUMP

On similar lines, the Haunted Jack in the Box

(hsmag.cc/potCxt) also took shape as its maker

went about building it. Sean Hodgins tells us that he

knew what he wanted to build, but “just didn’t know

exactly how it was going to get there”. Sean used

his background in automotive technology and AI to

put a Raspberry Pi to good use and automatically

cranks the popular prop making it a lot scarier.

First, Sean 3D-printed a shell for the contraption.

He then paired a Raspberry Pi Camera Module to a

Raspberry Pi 3 that runs a face-detection script to

fire up a servo motor that cranks the music box and

fires up Jack. You can find the Python script, along

with the complete schematics for the project, in

Sean’s Instructables page. He warns us that anyone

looking to replicate his build must be prepared to

deal with a lot of wires strewn about the toy.

From one Halloween staple to another. Jack-O-

Lanterns are the most common props you’ll find

on Halloween, and while you can be creative with

them, making them throw flames will definitely turn

heads. Markus Haack’s fire-breathing Jack-O-Lantern

(hsmag.cc/YfSczk) is IoT-enabled using MQTT.

Before you begin, please understand this build

is extremely dangerous because it deals with fire.

Please replicate this build after taking appropriate

protections. We’d also like to repeat Markus’s

warning: make sure you place the pumpkin at a

safe location to not harm any person or property.

We’ll add our own warning: compressed flammable

gasses and candles are a hazardous combination.

Take responsibility for your own safety and only

work with them if you’re confident of the safety of

your approach.

The project basically involves triggering a can of

WD-40 to spray its contents across a burning candle

inside the pumpkin, which erupts outside giving the

impression that the pumpkin is throwing flames.

Needless to say, the first part of the project involves

building the flamethrower. Markus has built one atop

a wooden platform. The key element of the platform

is a servo-controlled piece of wire over the nozzle of

the WD-40 can. The servos, in turn, are triggered by

PIR motion sensors that detect when someone is

approaching the prop. The project is simple to wire

and is run via the minuscule ESP8266 board.

If you’re reading this magazine, chances are you’ve dabbled with microcontrollers

to do interesting things. Wearable microcontrollers are specially designed to be

concealed in clothing and can be sewn into costumes. Many of them are also

washable, so you don’t have to remove them before chucking the costume in the

washing machine.

The LilyPad Arduino was the first board that featured sew-through contacts

for stitching soft circuits. It’s still popular and currently available in several

versions and can be easily extended with sewable LEDs, sensors, and more.

LilyPad inspired the Adafruit FLORA, which has a lot more sewable modules.

If you don’t require too many swappable modules, SquareWear might have

everything you need for your wearable project.

Adafruit’s Gemma is another popular microcontroller that is ideal for tiny

wearables that don’t require a lot of I/O. If you need more I/O without

compromising on the size, there’s the TinyLily Mini, which lacks some of the

conveniences you get with other boards. There’s also the Teensy, which isn’t

designed for wearable as such but is popular for them because of its minuscule

size. Despite its size, this Arduino IDE-compatible microcontroller packs in quite

a punch. Several projects in our feature use the Adafruit HalloWing, which

was designed specifically for powering Halloween projects. It features a TFT

display, light and motion sensors, a speaker driver, and more so that you can

roll it into your Halloween costume or prop with ease.

BODY BOARDS

Markus uses the

Homie project to add

MQTT support to his

build in order to make

the pumpkin spit fire

from a mobile phone

Using an Echo Dot

can be a security

issue. Since we don’t

want random people

to talk to Alexa,

always remember to

mute its microphone

Sean encourages

anyone who

wants to replicate

his build to come

up with some

different ‘scary’

sequences