Mouth of a Beast

My goal with this project is to create a fun interactive project that especially children can enjoy and recreate if their hearts desire. I wanted to take a regular old plastic container and transform it into a beast and holder for my arduino. This project challenged me to learn new interfaces such as using a buzzer, touch sensor, and potentiometer. It also challenged me to to really think about physical landscapes and made me realize how important planning is when creating interactive objects; not only for me but also for the audience. I felt that this project was a great way to open up my thinking and challenge me to plan ahead much more than I am used to, from breadboard setup to actual fabrication.

Also, make sure to skip to step 7 for a much cleaner breadboard to follow off of!

(1) Potentiometer

(1) Button

(1) Touch sensor

(1) Buzzer

(1) LED

(1) Arduino Nano 33 IOT

(1) Breadboard

(1) Micro USB to USB

(1) Plastic Container

Multiple jumper wires

A few resistors

I have a few inputs and outputs within this project. My inputs are my button, potentiometer, and piezoelectric sensor. My outputs are my LED and buzzer. When the mouth of the beast is open, you are allowed to control the LED inside with the button and the potentiometer; you will be able to control whether the LED is on or off and how bright the LED is. Inside the mouth I will also be creating a tongue out of felt to put the piezoelectric sensor in. When you touch the tongue of the beast the buzzer will start to go off.

Even though I used the Adafruit Circuit Playground Classic in these photos rather than the Arduino Nano 33 IOT, the concept is still the same, and I switch over to the Arduino Nano 33 IOT later in the project. In this set up the goal was to have an led light up as I pressed the button. I started by hooking up the the ground and the button pin. From there I hooked up the power source (3.3v). I used jumper wires to hookup the button to the power rails, and then I connected a led to a pin number. I added in resistors to keep the project from short circuiting and connecting the button and led to power.

After getting the button to turn on the led, my next goal was to get the potentiometer to function and allow me to change the brightness of the led while the button is pushed and keep the led on. I hooked up the potentiometer to the power rails and hooked up the center connector to a pin on the Adafruit Circuit Playground Classic.

In this step I took the setup from the Adafruit Circuit Playground Classic and transcribed it to my Arduino Nano 33 IOT. The board remains relatively the same, except in this version I added the potentiometer to the actual breadboard instead of hooking it to the board. I also switched out my button because my button was defective and not allowing me to switch the led brightness while holding it. Since my Arduino is going to be hidden in my project, I used jumper wires to extend out the led so that the user will be able to see the led without the breadboard.

The sensor does need to be soldered, but I at least set it up and got it to work with my code. I connected the inside and the outside to the ground and connected the center to a pin on my Arduino Nano 33 IOT. The goal with the sensor is to be able to interact with the white circle piece and have the buzzer make a noise when touching it. In addition, in step 7 of this project I do switch out my sensor for a different touch sensor, but the setup will be very similar.

My buzzer was set up by connected to ground and then connecting the other wire to my Arduino Nano 33 IOT using an alligator clip. As I touch the white circle on the piezoelectric sensor, the buzzer than reacts by making a noise to it. Both the buzzer and the piezoeletric sensor will be used in my tongue portion of the project.

In this step I rewired my board to create a much easier to read design. By simplifying the wiring, it makes it much easier for others to follow in my footsteps when recreating this project! I also found that the piezoelectric sensor did not work as well as the touch sensor, so I substituted it out. This step is extremely important because I was able to make my work look much more professional.

For my fabrication, I took a plastic sandwich container I got from the grocery store and transformed it into a beast. I used felt on the outside to make the project soft and kid friendly. For the teeth I used foam, and I used cardboard and felt to create the the surface the tongue sits on and the tongue itself. I bought some googly eyes to create personality, and used more felt to create horns and spikes to really go above and beyond. The cardboard piece the tongue sits on is set within the project but is easy to move in and out in case I need to look at the wiring. In the front and on the side, I created two holes towards the bottom where I can touch the button and turn the handle of the potentiometer for the led. In the back of the container is another hole for my micro USB to USB cable to pass through. Inside the arduino is placed on a ramp so that the button and the potentiometer can fit through the holes I created and provide the audience with easy access. Within the tongue I created a pocket, so I can slip the touch sensor in and out as needed.

My Code

This is a link to my Mouth of a Beast code within GitHub.

This is my final result! I got everything to work: the buzzer, touch sensor, led, potentiometer, and button. This project really strengthened and challenges my abilities to create something that was interactive but also aesthetically pleasing. I'm proud with the work I did, and hopefully others do not find it difficult to replicate for themselves and the potential youth in their lives. The materials I used were mostly on the cheaper side, so this project would not be too difficult for someone to recreate on a budget. I just hope my audience learned as much as I did in this process.