Scary Useless Box

The aim of this project was to create a useless machine from scratch and then decorate it in a way to be scary, The basic functions from a useless box are met but somehow ambiented into the halloween theme. In the following steps, you will be able to recreate our project in the simplest and most effective way, with the list of all the requirements.

There is not a ton of materials required to recreate this project. The only thing tha may vary from yours is the way you will be doing the outer case. In this project, all the outer components had been 3D printed so you can use wood instead of PLA in the case you don't have access to a 3D printer. The materials come down to the following:

Electronic Parts:

• 1 Arduino UNO board
• 1 COM Cable
• 1 Servo motors (LINK)
• 1 3-Position toggle switch
• 1 1K Ohm resistor
• 2 LED's
• 8 Jumper Wires

Parts:

• 1 Outer Case
• 1 Large Cover
• 1 Switch Holder Cover
• 1 Skull
• 1 Finger Bone

Materials:

• PLA 3D filament
• Tin Roll

Tools:

• Ender 3 Pro 3D Printer
• Arduino Software
• Soldering Iron

The electrical scheme is very clear and easy to understand. First, we will connect the servo to a power source (5V) and a ground. The last cable remaining being yellow, brown or white will be the signal one, connected to the pin number 3.

Once the servo is connected, we proceed with the switch and the LED's. To connect the switch we will run 3 cables from it, one to 3,3 v, another to ground and finally one for signal paired with the 1K ohm resistor to the pin number 2.

The LED's will be running in a series layout having the input voltage from pin number 4 and the connecting the last LED to the ground. This two LED's need to be soldered.

Finally, we will be running a connector to use a 9V battery to run the arduino inside the case and delete the cable. This will make the project portable and better looking.

The building process is as simple as it gets. Once you get all the 3D printed parts ready (wood, cardboard, etc) the assembly is very easy:

Connections

Some of the parts require some soldering to connect between them. The following steps need to be made in order to get the project together:

1. Inside the skull there are two LED's that need to be soldered in a series manner. From the anode running to the catode and then going to the anode of the next LED closing the loop. One end will be connected to positive and the other end to negative.
2. A resistor of 1K ohm needs to be soldered to two pins in between the switch and the pin number 2.
3. All three pins from the switch need to be soldered to run cables to the arduino pins. One will be going to the 3,3v source, the other to number 2 pin and the last one to the ground.
4. Finally and optional, use the soldering iron to make the hole in the large cover to run the wires through it.

Assembly

• The first thing you need to install is the servo. Located in one of the sides. It is mounted using two philip's screws to hold in position. The cable will run through out the hole besides it, clearing the space for the arm to move freely.
• Once the servo is installed, we proceed to connect it to the arduino. All the main connections will be made in this step.
• Next, take the switch holder cover and screw in the switch. This step may require some pliers to hold the piece tight to the cover. Once screwed, use two philip's screws to place the lid on the case and fix it in the desired position.
• To continue, place inside carefully the arduino with all the connections and the battery. This step will require some effort and care to not disconnect any pin.
• When you have all the parts inside, we will proceed to make a hole in the top of the large cover to run the skull wires through. This will allow a smooth finish to the project, hiding the wires inside the box.
• At this moment, we are near to finishing the build. Now it is the moment to atach the finger bone to the wheel of the servo. This process will require som glue to hold in position.
• Finally, the last step is to place a rod through the holes in the large cover to allow the movement. This will hold it in place and allow the arm to move it without problems.
• At this point yor project is ready and fully assembled!!

It's been a challenging project due to the difficulties found in the code and also inside the building process. A lots of hours have been spent trying to figure out the lenght of the servo arm, the dimensions of the box and also all the ways to fit the arduino inside the box.

The final result of the project is very rewarding, being able to build from scratch this product and believe it or not, functioning without any problem. It's been a interesting project to develop and try our skills from arduino inside the code and also the building skills inside the assembly process.