RFID Fridge

A smart refrigerator for the home

Motivation / Introduction

We wanted to design a system that would be able to track the stock of a refrigerator. Knowing what is in your fridge is powerful information if you can easily collect the data. There are a number of applications for such a system but it would be tedious to do all the data entry by hand. Our system would track the stock of your fridge by monitoring movement with Radio Frequency Identification. If every item has its own RFID tag we can make estimations on usage and know when it is time to head to the grocery store.

Overview / High Level Design

Our system tracks items as they move in and out the attached fridge with Radio Frequency Identification. When placing items in the fridge or taking them out, you simply move the item near the RFID reader and it will change the status of the item in memory. Items are initialized into the system with a barcode scanner. When a new item is to be placed in the fridge, it is first scanned by its barcode. The barcode identifies the item when it is cross-referenced with an online database. This new item is then given a unique RFID tag for identification. The current state of the fridge is displayed on a small screen. The different modes for the screen can be navigated with a keypad. All of the information is also accessible on the web as our processor uses an Ethernet connection to act as a server. We also have a temperature sensor to monitor the conditions in the fridge.

High Level Diagram

The final product of our fridge was a large success. We were able to create a system that could pair barcodes and rfid tags, allowing a user to then track their movement of the rfid tags in and out of the refrigerator. Peripherals such as a screen, keypad, and temperature sensor provided additional functionality and integrated well into the product. However, we were not able to incorporate every additional feature we would have liked to. We were not able to get sound integrated in time for our demo, and we could have added additional components such as a printer (for printing grocery lists), which might have given more experience with other protocols such as SPI and I2C. Given more time, we also would have perfected our client side TCP/IP lookup, to allow lookups from actual online UPC databases to work more consistently.

Additional photos on each individual device page (see menu at top)
Members / Division of Work
Zach - Display, Ethernet, System Integration
Dan - RFID, Thermometer
Mario - Barcode Scanner, Low Pass Filter
Andrew - Keypad, Poster
SmartFusion User's Guides - http://www.actel.com/products/software/smartdesign/docs_mss.aspx
FreeRTOS - http://www.freertos.org/
uIP - http://www.sics.se/~adam/uip/index.php/Main_Page
uthash - http://uthash.sourceforge.net
TI Series 2000 - http://focus.ti.com/docs/toolsw/folders/print/ri-k3a-001a.html
LM34C Temp Sensor - http://www.national.com/ds/LM/LM34.pdf