Final Project Week 3: Building

Now that we had our code worked out, and all our materials had finally arrived, it was time to put our device together. Below is a description of how each component, as well as the final product was put together. 

Soldering/Heat Shrinking

In order to connect both the motor and touch sensor to our Arduino we first needed to attach pins to the end of their wires through soldering. In the case of our button, it was important to solder the wires onto the "normally open" connecting section on the button, as that is how the touch switch we used to test our code was set up. The "normally open" setting means that no current will flow when the button is unpressed, and current will flow through when the button is pressed. One the wires were connected, the exposed portions needed to be covered by heat shrining a section of wire covering over them. 

Arduino

One of the challenging parts of this project was to set up the Arduino and breadboard while we were coding, and determine whether is was our code or setup contributing to the device's dysfunctionality. Below is our Arduino's final setup including the wiring of the ultrasonic sensor, button, motor, and battery pack. 

The Box

In order to prevent the wiring of our device from coming into contact with water, and also to make the device more aesthetically pleasing, we decided to house all the components of the device inside one box that would rest on top of the toilet. 

The box we decided to use was a clear, plastic box we found in our classroom. While it was big enough to house all our components, it needed a couple alterations. The first was that it did not rest flat on the surface of the toilet tank. This was remedied by riveting a  a 1/2 cm thick piece of delrin to one of the box's sides to act as the new base. We wanted the box to rest on it's sides so that the lid could be facing the wall and be easily removed to allow access to the box's contents.

The box also didn't have a way to securely stay on top of the toilet tank, which we solved by adding four suction cups to the bottom of the box; next to, rather than on top of the delrin sheet to prevent the box from tipping back and forth. The base of the box including the delrin sheet and suction cups is shown below:

We  additionally wanted to make sure that kids would not be tempted to play with what was inside the box, so we decided to spray paint it silver (originally it was clear). 

The box also need to be able to accommodate the button, ultrasonic sensor, and motor wire which needed access to the outside environment to function. We decided to achieve this by making two different circular cuts on the outside front portion of the box (opposite the lid), and then a small rectangular cut at the base of the lid. The rectangular cut was made using a bandsaw, and sandpaper was used to smooth the edges. For the two circular cuts, we first measured the diameters of the button and sensor, then used a compass the trace out matching circular stencils. These stencils were place on the appropriate places on the box, and a drill press with a small drill bit was used to trace the circumference of each circle. Once this was done we used a box cutter to finish up the cutting process and sandpaper to smooth out the holes. The image below shows the sensor and button fit through the two circular holes on the front.

Once these holes were complete, we could then secure the rest of our components inside the box using hot glue, gorilla glue, and electrical tape. When setting up the inside of the box, we took care to make sure that the battery pack could easily be removed when needed. The box was set up as below:

Motor Set-Up

Once the box was ready to be put on top of the toilet , we could then set up the motor inside of the tank. We set the motor up using the video shown below:

Our Set-up:

All that's left now is to present/demo our device to the rest of the class!