Spooky Pumpkin

Our project is a pumpkin intended to be used for Halloween. Using Arduino, we have created a pumpkin whose eyes move and red lights turn on when there is no light or when the ECHO sensor detects movement.

Arduino board

Servomotors x2

LEDs

ECHO sensor

Photoresistor

Jumper cables

Perfboard

Protoboard

Solder

Plastic Pumpkin

Halloween eyes

Wire

Cartonboard

Esquematic reproduction of the circuit.

Diagrammatic representation of an algorithm

We must think about what we want our pumpkin to do, and the movements, in turn, go configuring with the code so that our object does exactly what we want. 

Purchase the materials you want to work with and check separately that each and every one of them works correctly.

Once we have checked that the components work and we have our code ready, we are going to use the breadboard to see that the codes we have programmed actually work with our materials. This, in turn, will help us to know where to connect each component and its jumper wires.

Once we have checked that our code works correctly, let's move on to assembling the pumpkin. We will start by assembling the eyes. Before placing them in the pumpkin, we must solder the servomotor to the perfboard. We must also solder a cable that allows us to connect it to the Arduino board to allow the connection. Once the technical part is done, we will move on to mount the eyes. To do this we will connect a wire to the servomotor shaft and pass it through the middle of the eye of the pumpkin, leaving the servomotor inside the pumpkin and the excess wire outside. In the excess wire on the outside, we are going to pin our halloween eye, this will make that when our servomotor moves, so does our eye. Keep in mind that the servomotor must be still, so we are going to glue it to a piece of cardboard and this on the wall of the pumpkin. 

After mounting the servomotors, we will do the same with the LEDs. First, we will solder the LEDs to a perfboard and in turn we will solder a wire that will allow the connection between the Arduino and the LED. As we have used bare wire, the ends of this we are going to join them to a jumper cable so that when we connect it to the Arduino board it does not come loose. We are going to place the LEDs inside the walls of the pumpkin so that they light up and are very scary. 

Now we are going to mount the ECHO sensor, this sensor is the one that will activate our pumpkin, when someone passes in front of it, our eyes will move and our lights will turn on. We will repeat the same process that we have carried out before, we will begin by soldering the ECHO sensor to the perfboard. Then we will solder a wire, which in turn will be soldered to a jumper to make the connection with the Arduino more precise. Once this is soldered and connected to the Arduino board, we will place it inside the pumpkin. Knowing that the sensor can not be covered, we will place it in the mouth of the pumpkin, as it allows us that when people pass in front, the sensor detects it and the pumpkin is put into operation. 

Another way our pumpkin works is through light. When the light is turned off the gourd will be in operation. Again we will repeat the process of soldering the component and the wires, and its subsequent connection to the Arduino board. When everything is connected, we will place it in our pumpkin, with the help of cardboard, we will place it in the hollow of the pumpkin to detect the light changes.

In conclusion, it is not a simple job, since you constantly have to be doing trial and error, sometimes the fault is in the code and sometimes in the assembled circuit, components can fail, wires can fail, and you have to know how to look for and find the error of the fault. 

Apart from that, you have to make a shaft for the eye, since the Halloween eye can not go directly hooked to the servo, because otherwise it would not rotate properly. At the time of welding many errors can appear, therefore it is necessary to weld with care and not to be very abrupt in case it can break.

It is not a very complex project, but it requires time and patience, because not everything comes out perfectly the first time. It has been a different, original work and at the same time allows you to put into practice the knowledge acquired both with the Arduino code, and when assembling circuits and simplify them.