Halloween is a well known holiday. Kids run out in the streets, teenagers have fun and adults enjoy watching classical or innovative costumes. Everyone takes part either by playing pranks or treating in order to be safe. But, as always, there are some people that have not got the whole spirit of the event. We know that it is everyone's right not to participate but, on the other hand, we cannot accept our kids being disappointed or annoyed by those people... So this year we decided to provide a solution to this problem. We designed a prank that may help both sides. It may be used by those that do not want to participate in order to scare any unwanted visitors. On the other hand, children could use it to scare those who do not want to give candy. It is a mask that can understand movement due to infrared technology and is programmed to spit water on the unsuspecting victim. As you can imagine, the victim will be scared by the water and in addition by the lights that will automatically turn on inside the eyes of the mask. Just imagine the whole thing in the darkness of the night. Pretty scary, huh?

Step 1: Materials

This is what you will need

-For the automatic "spitting" and led eyes

1.an arduino board
2.a PIR sensor
3.one servo motor
4.an adjustable watering sprinkler like the one in the picture
5.fat and thin plastic watering pipes(usually used for automatic irrigation system)
6.a faucet connector
7. two leds
8.some screws
9.connector wires
10.some pieces of thin wire
11.hot glue gun
12.small to big pipe connector

-For the mask (optional)

1.plaster cloth (you can get it from your local pharmacy)
2.some drops of oil
3.acrylic paint
4.varnish

Step 2: The Mechanism - Part 1

First of all connect the servo to the sprinkler. In order to achieve this, hot-glue the removable servo arm onto the sprinkler.

You should be quite careful in order for both the sprinkler and the servo to be able to rotate around the same axis.

Step 3: The Mechanism- Part 2

What you need to do now is to mount the servo onto a piece of wood.

Start out with a rather big piece, so that you can later cut it to fit exactly inside the mask.

Make a hole in the wood so that the swiveling part of the servo-sprinkler system can rotate freely.

Then place the two parts above the hole,making sure that they can rotate, and mark down where the wire will pass through the wood.

Now you can make the small holes with you drill.

After that, you re ready to tie the servo-sprinkler onto the wood using the wires

*please refer to the pictures for deeper understanding

Step 4: The Mechanism - Part 3

Connect all the tubing following the pattern shown in the pictures

Afterwards remove the cap so that the sprinkler will spray forward

***for better understanding refer to the photos

P.S.You can skip this step if can get a faucet connector like this one

Step 5: The Mask (optional)

If you already have a mask you can skip this step.

If you decide to make your own mask you will definitely need another person to help you.
First of all halfway fill a bowl with water. Now spread some drops of oil on your face (or whoever's will be the "mold" for the mask) in order for the mask to unstick easily from your face when finished. Then cut the plaster cloth in pieces of a size that suits you and dip them inside the water one at a time. Carefully place each piece on the face, covering up the face completely except for the mouth, nose and eyes. After a few minutes you can take it off. It should be quite easy. Afterwards you are free to decorate it the way you want. Last but not least, you should coat it with a varnish in order to prevent it from getting messed up in the case some water hits it.

ATTENTION!: Be careful that no plaster gets into someone's eye as it may cause itching and even damage the eyes.To prevent something like this from happening, the model can be wearing swimming goggles while being covered with plaster.

Step 6: Attach PIR Sensor

Carefully drill a hole in the mask's head and fit the PIR sensor in it. Then glue it on using hot glue.

Step 7: Final Assembly - Part 1

Now it is time to put all the parts together. Modify the wooden piece on witch the servo is attached (from now and on I will call it "main wooden piece") so it can fit inside your mask. Watch out so that the water that will be sprayed by the sprinkler can freely come out of the mouth without wetting the mask. Then screw: 1. the mask onto the main wooden piece (refer to photo) 2. the wooden rod onto the main wooden piece(optional) 3.The secondary wooden piece onto the main one (this is where the electronics will be mounted)

Afterwards mark where you want the led-eyes to be using a pencil.Now glue the leds on the marked spots.