The Smart Fridge

How might we create a fridge that keeps us from running out of and wasting food?

How might we create a fridge that keeps us from running out of and wasting food?

A personal project which focused on a works-like prototype using the Arduino.

Most of the commercially available “smart fridges” are simply fridges with WiFi and Pandora. Personally, I consider something to be made “smart” when it integrates technology in order to better achieve its main function. The main function of a fridge is to keep your food fresher for longer. Therefore, any smart features should be focused around your food, not your entertainment.

The Smart Fridge is an Arduino powered system that includes a milk scale for measuring percentage remaining of milk (or another liquid), an egg sensor that can count the number of eggs remaining, and a RFID tag system that tracks what is currently in the fridge. All of the information can be accessed by texting the fridge "What do I have in stock?" to which the fridge responds with a list of current items and status of the eggs and milk.

This idea was sparked by my frustration with grocery shopping. You see, I'd get to store, buy what I wanted, and then get home only to find out that I'm out of ketchup to go with those corn dogs I just bought. At the time, I didn't have a car so any trip to the grocery store was a challenge.

I created the Smart Fridge during the summer after my sophomore year of undergrad with a grand from the Shanahan Summer Student Directed Projects Grant. I did all of the coding, hardware design, and brainstorming myself with some help and advice when required. Below, you'll find some screenshots of the texts and photos of the project. If you'd like to hear more about the step by step process, I documented the whole project at

First test of the text response.
Adding the milk scale portion to the text response.
In order for the fridge to know what was inside, I used RFID tags which would be attached to each item. For this prototype, the user would have to tap the tag on the RFID Reader in order to check out the item. Ideally, the tags wouldn’t need to be tapped but rather the reader would be able to sense all the contents at once. I wasn’t able to find a tag reader strong enough that could work with Arduino and be able to do that.

I also built a milk scale which would calculate the percentage of milk remaining based on the weight.

Finally, I was working on an egg sensor which would count the number of eggs left. Unfortunately, I never got that one working properly.

Overall, I was able to identify a problem, find a solution, and create a version one prototype. Even though it all died at the very end, I’m proud of what I was able to accomplish. So much of this I had never attempted before and I had my doubts during the projects that I’d ever get any of it working, but I did.

Other projects: