Final Project / Maker Faire

Project Description

You can look at my proposal and initial design for for this project here. My Proposal

Here is the second design of the container for this project.

For this project I attempted to create something that already existed with my own personal twist. I came about this idea after contemplating what types of hardware I wanted to use. To challenge myself, I decided to get two pieces of electronic hardware to work together via a microcontroller in an inventive way. The two items I chose were an LED pixel matrix and an Alcohol Gas Sensor.

Progress

I was able to find some information on the internet about the hardware I chose. First, I found a simple wiring diagram for the alcohol sensor which was extremely helpful. Then I found information at Adafuit about their 8x8 Matrix . Once I read these, envisioning my project became much easier.

The LED matrix has multiple pins in the back so it can communicate and receive data. It came with a backpack that needed to be soldered to it in order for it to easily communicate with a microcontroller. By doing this, the LED goes from a multi pin setup to a four pin setup. The alcohol sensor was also easy to get going thanks to the wiring diagram I found. Only four wires are needed to get this thing working.

I combined two pieces of example code from each of the manufactures. Then I made some adjustments to make it a little more personal. The use of an array is used to create and color each image to the display. I had problems making the thing work at first. I kept getting compiler errors that had something to do with the necessary libraries. So I started commenting each one out and recompiling afterward. I found that one was not needed. Here is the code I used to make it work.

I created the box for this makeshift breathalyzer in SketchUp because I wanted it to be a little more stylish. I was initially thinking of having it in a 3D printed case. Once I sent the file to someone to be fabricated, I was told that it would be ridiculously expensive to fabricate in plastic, and that I should probably redesign my sketch so it could be fabricated in wood. Due to time constraints I used a website called Box Designer to create a quick and easy PDF to send for fabrication. Once I glued the box together, I drilled pilot holes for the standoffs to be easily mounted so I could secure the microcontroller to the box. I also cut holes in the back so I could make the necessary connections. Then I labeled the wires to make things easy for me to connect and disconnect the hardware as needed.

After I had everything working, I secured the LED matrix to the top of the box. This was done by cutting a hole for it using a coping saw. This square hole allowed for most of it to fit through, except for a thin overlap which I used to glue it to the roof of the box. This allowed the LED side to be visible by the user and the backpack to fit through and be connected to the microcontroller. I obtained a tube to house the alcohol sensor and necessary wires then drilled a hole for it to go through the lid of the box.

Maker Faire

A requirement for the final project was to take what I made and display it at Maker Faire .