CURIOUS PUMPKIN (Rotating Eyes Jack-o'-lantern for Halloween Decoration)

We were proposed from our university, ELISAVA, to design and implement a product for Halloween either a product of decoration, a costume, etc. Taking into account all the elements that we have learnt on class related to the arduino open-source hardware and software.

We decided to create a jack-o'-lantern, but to make it scarier and to take advantage of the knowledge acquired in class, it's eyes will turn depending on the victim's position, using two servomotors (one for each eye) and 3 sensors, (we will detail all the materials a step later), and we will also use a few red LEDs to make the eyes glow that will activate depending on the sensors.

In this instructable you'll find at the first part the programming and arduino assembling and the second one, in which we will explain step for step the prototyipe building.

-Arduino KIT (which includes LEDs, cables, and resistors)

https://www.amazon.es/ELEGOO-Conjunto-Iniciaci%C3%B3n-Arduino-Tutorial/dp/B06W2KF3PJ/ref=asc_df_B06W2KF3PJ/?tag=googshopes-21&linkCode=df0&hvadid=195276016045&hvpos=&hvnetw=g&hvrand=18008212034994876278&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1005424&hvtargid=pla-358213372517&psc=1

-2 Servomotors 180º

https://www.amazon.com/Dorhea-Arduino-Helicopter-Airplane-Walking/dp/B07Q6JGWNV/ref=sr_1_7?crid=13KQH3YCFUKI2&keywords=servo&qid=1667408575&qu=eyJxc2MiOiI1Ljk4IiwicXNhIjoiNS40NyIsInFzcCI6IjUuMTQifQ%3D%3D&sprefix=servo%2Caps%2C204&sr=8-7&th=1

-3 Ultrasonic sensors

https://www.amazon.com/Dorhea-Ultrasonic-Distance-Duemilanove-Rapsberry/dp/B07L68X65N/ref=sr_1_5?crid=ZN5RFIBGLPDW&keywords=arduino+sensors&qid=1667408616&qu=eyJxc2MiOiI1LjAxIiwicXNhIjoiNS41NCIsInFzcCI6IjQuODIifQ%3D%3D&sprefix=arduino+sensor%2Caps%2C191&sr=8-5

-Natural Pumpkin

-Spoon and knive (for carving the holes and emptying the pumpkin)

-Table tennis balls (for the eyes)

-Color markers (for painting the eyes)

-Glue gun

-wood sheet

-Nails (to fix the wood sheet to the pumpkin)

We will start from this point, the arduino configuration, once we have it working right, we will start with the pumpkin, and then we will explain how we did found the way to unite them.

In order to make this part more clear, we will add a schematic of the electrical connections, made with Wokwi.

We're also attaching a picture with the flow diagram of our code followed and the actual code in a zipped folder, where you could download and copy the pats in which you are interested in case of following the instructable.

The 3 sensors will be pinned following the code (pins 2, 3, 5, 6, 7, 8) and its comments, same goes for the 2 servos (pins 9 and 10) and the LEDs and resistors (pin 13). Each sensor will be put on one side of the pumpkin and when somebody approaches the pumpkin on one side, one of the sensors will detect it and the eyes will turn to point at that direction. There are 4 positions for the eyes, one for each sensor and the default one. When two sensors are activated at the same time the eyes will look to the default position (looking forward) and the eyes will glow thanks to the LEDs. If no sensors are activated the eyes turn to the default position.

You can buy the seeds or rob them if you're filthy enough. You'll have to wait from 4 to 7 months to grow the pumpkin depending on the season. If you are maximum filthy you can go straight to the point of stealing the already-grown pumpkin from a vegetable patch.

Drawing the hole at the bottom of the pumpkin in order to make it not visible, the diameter should be about half the size of the pumpkin. The line will help us to cut a clean line.

We want to access the inside of the pumpkin, that's why we have to make a hole in it. With the help of the knife and the line that we draw in the last step, we will start cutting through it.

Using the spoon, and a lot of patience, we clear the interior, being careful since we do not want to break it.

We want to use the inside and therefore make soup out of the rest.

Once we have the pumpkin empty, we proceed to cut the holes for the eyes, in which we will add the tennis table balls, and the mouth and nose, in which we will add the LEDs.

For the eyes we use the tennis table balls that we can get from the internet or any local shop, we cut them in half to glue the servo inside.

Then we paint them in the scariest way that we can with the markers and protect them with nail polish.

This is one of the most crucial parts of the job, so it is very important to do it with patience and care. We weld all the corresponding wires to be able to fix the sensors and the LEDs with the Arduino.

We glue the servos with the tennis table balls, using silicone.

The wood sheet is fixed to the inside top of the pumpkin using nails, at first it can be perceived as a rudimentary way to do it, but once you try it, we can see that it was well fixed and it definitely works.

Then we also glue the servos to the wood sheet living a few millimetres.

Attach the lights to the structure on the inside roof of the pumpkin, next to the eyes, so that they are illuminated. For this, you will need a strong glue and to press the light for a few minutes to achieve the best attach.

Finally, we place the sensors, two on the right side and one on the left. To fix them we use nails. 

Also, depending on the position of the sensors, we fix the decoration with tape, in this case, plastic plants, which will hide the presence of the sensors as much as possible.

As a conclusion, we would like to add that it has been a challenge against the clock, since working with natural materials, such as pumpkin, we had limited time, as it could be that it could rot. 

Therefore we recommend doing this project in less than a week and not to put the pumpkin with the electronic components in the fridge.

We believe that making a project of this type is a good way to learn the language and operation of arduino, since making a prototype makes everything much more practical and enjoyable.

We wish you a happy Halloween!