Refrigerator/Freezer User Interface

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Please complete the following information

Contact Information

University and Department: University of Pittsburgh at Johnstown

Team Members: Brandon Quinn and Ryan Blough

Faculty Advisors: Stanley Pisarski

Primary Email Address: Brandonquinn8@yahoo.com

Primary Telephone Number (include area and country code): 724-454-5662

Project Information

Project Title: Refrigerator/Freezer User Interface

List all parts (hardware, software, etc.) you used to design and complete your project:

Sensor

50Ω 2W Resistor

6.8KΩ Resistor

10KΩ Resistor

Capacitor

Transistor

Diode

Fan

Insulation

Wire

Scale

Scanner

DAQ

PC

LabVIEW (Student)

12VDC Power Supply

Refrigerator

Describe the challenge your project is trying to solve.

The household refrigerator/freezer has remained relatively unchanged since General Electric introduced the first mass produced unit in 1927[1]. The refrigerator has always served the simple purpose of keeping food items fresh and at a cold temperature. Today every household has a refrigerator/freezer unit that many just take for granted. The refrigerator/freezer can be a much more important part of the home. There are many things that the refrigerator/freezer unit does not have or do that can be beneficial to the consumer.

            Refrigerators today provide the consumer with limited control of the temperatures in its compartments. Most refrigerators provide a simple knob that one must reach into the cold refrigerator environment to adjust, although recently manufacturers have provided digital control selection but the consumer must still reach into the unit. In addition, they have no assurance that the temperature they set is the actual temperature of the compartment.

            Today’s refrigerators are basically just storage containers for our food and beverages. Consumers possess no type of connection or interface with this household device. Food and beverage items are placed in and removed from the unit with no monitoring to allow consumers to know what or how much they actually have in their cluttered refrigerator or freezer. Additionally, food items regularly expire before they are consumed and unfortunately it is often discovered when that item is needed the most.

            The future of technology is moving toward the unification of man and machine. People are looking for more control and personalization in their everyday lives. The Refrigerator/Freezer interface is a step toward the future.

            The objective of the Refrigerator/Freezer Interface project was to design, assemble and program a system that allows the user to obtain control over item management and the temperatures of the refrigerator and freezer unit.

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[1] “Refrigerator History” The Great Idea Finder. 2005. 1 Oct 2009 <http://www.ideafinder.com/history/inventions/refrigerator.htm>

Describe how you addressed the challenge through your project.

2.2 Final Design

The following outlines the primary components incorporated in the final design of our system. Due to costs as well as availability, some of the components were modified from the preliminary design.

2.2.1 Desktop Computer

The team elected to use a desktop computer in order to run the overall system. This decision was made in order to create a prototype version of our system at a reduced cost as opposed by purchasing a touch panel PC.

2.2.2 LabVIEW

LabVIEW remained the program control of our project. This software application manipulates and displays data received from the barcode scanner, scale, and temperature sensors. LabVIEW allows the user to enter and view item information as well as control unit temperatures.

2.2.3 Barcode Scanner

The Barcode scanner scans the barcode located on an item, this allows the LabVIEW program to either recognize the barcode as a repeat purchase or allow the user to type in information to the database that will be associated with that particular barcode number.

2.2.4 Digital Scale

The digital scale with Serial DB9 connection computer interfacing is used to measure and communicate the weight of each item to a database every time it is used and placed back into the refrigerator or freezer unit. Each time an item is weighed LabVIEW updates the information in the database. The scale has the capability of measuring a maximum weight of 150 lbs and is accurate to 0.2 lbs.

2.2.5 Data Acquisition Module

The Data Acquisition Module works as the communication hub for the various devices including the computer, temperature sensors and relay circuits. This device communicates and powered through a USB port.

2.2.6 Temperature Sensors

For the final design, the temperature sensors were built from transistor packaged sensors and interfaced with the input ports of the Data Acquisition Module. The sensors had the capability of determining temperatures from 0°F to 300°F with an accuracy of 1°F.

2.2.7 Circulation Fan

The final prototype design of our project required the conversion of a single compartment miniature refrigerator into a two-compartment unit with both a freezer and refrigerator. This required the addition of a circulation fan to pull cold air from the freezer into the refrigerator compartment.

2.2.8 Relay Circuits

When the Data Acquisition Module enables an output port, the relays actuate the refrigerant compressor and the circulation fan. The contact voltage switched by the relays is 120VAC and the coil voltage is 12VDC.

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