The University of Michigan holds several Hack-a-thon events a year. These events bring together hundreds of the brightest students in the university and challenges them to use their creative skills to build and create products that have never existed before. This blog post outlines my submission to the 2016 Make-a-thon. My partner and I created a smart spicerack that connects via an Arduino Uno to your computer and indicates where your spices are located. This submission won first prize of $1,000.
We came up with the idea to do a Smart Spice Rack a week before the competition. My partner was in the art school at Michigan and loves to work in the wood shop. I am in the engineering school and I wanted to use electronics like the Arduino and shift registers to make something smart. We took our two passions and had a brain storming session at our favorite Ann Arbor bar, The Black Pearl.
We looked at the bar and thought, “wouldn’t a smart bar be nice?” This discussion eventually led us to isolate our concentrations on improving the home kitchen. A lot of ideas were thrown around like a “smart island” or a “smart fridge”. Maybe even a hands free cookbook eBook. Eventually we came across the problems that arise when searching for spices.
The Smart Spice Rack is Born
We decided that searching for spices is a pain in the ass. Even the most organized chef, like my mother, still has over 50 spices that are all over the place. We thought to ourselves that there has to be a better way to search for spices.
In the picture above you see the final product of the Smart Spice Rack. It consists of 4 rows with indents to place your spice jars. Each location has an LED below that can turn on or off to indicate where that spice is stored. The magic happens when you connect the spice rack to your web browser. Using a chrome extension we were able to find all spices mentioned on a webpage and make those LEDs light up on the spice rack. This seamlessly allows the home chef to go from web-recipe to spices.
The Arduino uno has 14 output pins that allow programmers to turn on and off signals which toggle whether or not an electric current should be passed through those pins. Below is an image of an Arduino Uno.
The problem that I encountered was that we wanted to send signals to 32 lights! The limitation of 14 pins would suggest that we can only control 14 different lights at a time. This led to my research into shift registers. Shift registers allow you to control up to 8 different lights with only 3 pins. Already I could tell that I was on my way to solving the problem of limited output pins.
Next, I discovered a method called “daisy chaining” that allowed me to connect several shift registers together. Each shift register allowed me to control an additional 8 lights, still using only 3 pins. So, because we wanted to support 32 lights, I needed to “daisy chain” 4 shift registers together. So thats exactly what I did. The image below is the schematic I followed to create the circuit for our spice rack. If you have a keen eye for circuits, you can see it still only requires 3 Arduino pins, yet this schema allows me to control 32 different lights.
Getting the schema drawn is one thing, but assembly the circuitry is another! Jenna and I stayed up all night connecting this thing together! Even though Jenna (The artist) had no electronics experience, she was able to help assemble the circuitry!
The hardest part of this project was the electronics… But, the software was exciting too. Once the hardware was wired, I connected the Arduino via a google chrome extension to your web browser. The end result was pretty special. The google chrome extension could detect when you were reading a recipe, and would actually detect the spices listed on the recipe and send the signals to the spice rake, making the LEDs under the spices light up!
The user experience was speculator and everyone in the audience loved it! We won first price of $1,000 (which we desperately needed as college kids). I had such a good time building this product with Jenna and look forward to building more products in the future!