The Undead

The undead creature is awake again. Every Halloween, it tries to dig out from its grave in search of living humans and their bowels. So, every time it sees someone near, it wakes up and tries to go after them.

This is an ideal decoration for any part of the garden, if you want to scare anyone that passes around. It can be camouflaged thanks to its design. With a movement detector, every time a person walks near it, the undead will turn on the LEDs installed in the eyes, and it will start moving the arms simulating he is trying to get out.

The idea of this project is to use different Arduino components and, with the correct program, manage to make all of them work at the same time. This way, we can create a decoration that have movement and light without even touching it and get a scream of anyone.

Electronics

“The Most Complete Starter Kit Mega 2560 Project” from Elegoo

- Elegoo MEGA 2560 R3

- Servo Motor SG 90

- Ultrasonic sensor HC-SR 04

- 2 red LEDs

- 2 resistors of 240k

- Protoboard

- Male-male and male-female cables

- Cable to connect the microcontroller to the computer

Computer with Arduino IDE

Prototype

Shoes box

Skeleton's head and arms

Black paint

White paint

Yellow paint

Red paint

Brushes

White glue

Kitchen paper

Silver paper

Wire

Fishing line

Fake spiderwebs

Cardboard

Corrugated cardboard

Honeycomb cardboard

Foam board

Fallen tree leaves

Brown spray

Painter's tape

Sticky tape

Scissors

Pencil

Hot glue gun

Pliers

Hand auger

Cutter

Sawdust

1. Coding

First, we started by designing our Flow Diagram. To be able to do that, we had to determine what we want our prototype to do. In our case, we wanted to create an undead digging out of his grave moving simultaneously both of his arms. Also, its eyes had to shine red to impose and scare a lot more. We want it to move only when being close to it (we used a library to control our Servo Motor).

Then, we could proceed to open ArduinoIDE and start coding our program.

Flow diagram and code:

2. Setting our protoboard

For this part, we used our “The Most Complete Starter Kit Mega 2560 Project” from Elegoo. We were using the Servo Motor SG 90, male-male cables, male-female cables, 2 red LEDs, Ultrasonic sensor HC-SR 04, the protoboard, 2 resistors, the Elegoo MEGA 2560 R3 and the connection cable.

3. Building our prototype

PREPARING THE BOX

First we got our box, and we started to slowly introduce our electronics. In order to accomplish our objective, we made the needed holes in our box to implement our electronics and the movement mechanism for the arms.

PREPARING THE SKULL

Since our undead's eyes are going to shine red, we prepared the skull to be able to insert the LEDs. With a hand auger, we made two holes in the eyes' position. Then, with a cutter, we holed the interior to help the installation of the LEDs on the posterior part of the cranium.

MOVING MECHANISMS

To make the arms dig, we connected a wire to the middle finger and then to the servo. The servo offers a small turning radius, so we designed a longer one with a thin sheet of wood. With the help of a hand auger, we made a few holes in the wood: two to attach the wooden axis to the servo with the help of some fishing line and two to connect the wires of the arms. So that the arms can flex properly, we made a hole through the extreme of the arms' bone in order to create a rotating axis. We used a thick metal wire fixed under the box cover. Also, we are opened two little widows for the bones to rotate freely.

IMPLEMENTING THE ELECTRONICS

Then, we could set our electronics into our box and fix them with some sticky tape. To set our Servo Motor at the adequate height, we used honeycomb cardboard and with help of sticky tape we fixed it, so it doesn't move or fall.

(We made some testing checkpoints to see if all the components work correctly after every step forward if wanted)

To insert the LEDs into the skull and connect them to our protoboard, we used some male-female cables. Through the cavity previously cut with a cutter, we could fit the LEDs into each eyes' cavity.

DECORATION

To make our undead more real, we decorated the box, the skeleton, and we created a stone.

In the first place, we made the stone. The base is made of foam board, so we cut with a cutter two structures with the form that we wanted and stake it together with painter's tape. Then, we bordered with kitchen paper and painter's tape, rolling it up to create more relief. Meanwhile, we drew a bat, we bordered with silver paper, and we stake it all together to the structure with silicone. To make the structure more compact, we lined everything with a mixture of white glue, water, and kitchen paper. When it got dry, we painted with gray, black, and white to simulate a real stone. We add some fake spiderwebs at the end to make it more scary.

Secondly, we decorated the box where all the components are hidden and where the skeleton is. We started painting all the box of black, so it can be camouflaged. Then, we covered the top of the box with corrugated cardboard and white glue to create irregularities and make the fingers of the skeleton scratch, so it produces sounds. Finally, we painted the base with black and brown, we sprayed the sawdust with brown and stake it with the leaves and white glue. The intention was to camouflage it as much as possible with the real soil.

Finally, we dressed up the skeleton to create the undead body. We painted with black the arms and the head to simulate dirt. For the arms, we used old clothes, we gutted with the scissors, and we stake it with white glue, so they don't move. For the head, we paste fake black spiderwebs to pretend the hair.

With all the material, we accomplished our project, that consisted in creating an undead body that wakes up moving and making light when someone is near.