Senior Design II, Mid-semester Presentation October 5, 2010

Team Members Read Caver Hardware Design Microcontrollers Wireless Communication Technical Documentation Steven Price Software Development LCD Interfacing Energy Metering Hardware Implementation James Evans Software Design Hardware Implementation LCD Interfacing Website Maintenance Albert Shannon Hardware Implementation Energy Metering Microcontrollers Technical Documentation

Overview  Introduction Problems Statement Solution  Constraints Technical Practical  Design I Prototypes  PCBs  Enclosure  Packaging Product  Testing Plan

Introduction  SmartStat is a wireless thermostat with energy computation abilities  Used in both residential and commercial settings  Sets temperature for heat/AC to run, provides power monitoring capabilities  Thermostat module communicates wirelessly with 2 power consumption modules

NASA Sponsorship  Team SmartStat is sponsored by NASA. The team investigated the application of wireless technologies for sensor communication. Specifically, the IEEE Standard for wireless communication was implemented. ○ Emphasis on low power, low speed wireless communications.

Problem  Currently, there is no practical way to monitor the power consumption of specific high powered systems such as AC/heating units

Solution  Use low power wireless technology Synapse Wireless IEEE  Monitor energy consumption with wireless nodes  Send power consumption information to control unit (thermostat)

Solution

Technical Design Constraints ConstraintDescription Temperature Reading Range and Accuracy SmartStat must be able to read temperatures in the range of 50°F to 100°F, with an accuracy of 98% in the comfort range of 65°F to 75°F Energy Reading Range and Accuracy The energy monitoring modules must measure a voltage of 240Vac, maximum current of 60A, with an accuracy of 98%. Supply VoltageThe control unit must use 24Vac for supply voltage. Energy monitoring modules must use 120Vac for supply voltage. Wireless Communication SmartStat must communicate wirelessly using the IEEE standard. Transmission Distance The wireless modules must have a range equal to or greater than 500ft (unobstructed line-of-sight).

Practical Constraints  SmartStat must be compatible with the different types of HVAC systems. [1] Conventional [2] Water and ground source heat exchangers [3] Air source heat exchanger

Health and Safety  The control module must not allow the user to come into contact with hazardous voltages; energy monitoring modules must be sealed. [5] [4]

Design I Prototypes: Thermostat – Main Unit

Design I Prototypes: Energy Monitoring Modules

Main Unit Schematic LCD screen Synapse Module Pic24 uP HVAC Controls

Energy Module Schematic Voltage Converter Synapse Module Energy Monitor

PCBs Energy Monitoring PCBThermostat PCB

Final PCBs Energy Monitoring NodeThermostat

Enclosure  Hammond Manufacturing p/n: 1591XXCGY 6” x 3.2” x 1.8” [6]

Enclosure continued  Versa Laser Cutter Microsoft Visio used to create desired cuts

Enclosure continued Test Cut on a sheet of paperEnclosure lid ready for laser cutting

Enclosure continued Back of lidFront of lid after surface conditioning

Packaging Product  LCD and Button Mounting

Packaging Product continued  PCB fit and Switch Mounting

Packaging Product continued  Main Unit Fully Packaged

Packaging Product continued

 Ideal packaging for energy monitoring modules would be epoxy potting Extremely rigid, weatherproof, and protective Permanent enclosure, inaccessible after curing ○ Would be potted if released as consumer product, but deemed unnecessary for Senior Design

Testing Plans  Main unit Basic thermostat controls Synapse wireless module communication ○ Energy data ○ Number of wireless nodes connected  Energy Monitoring Modules Energy metering accuracy Synapse wireless communication  Synapse Wireless Modules  Power Supplies

References [1] “Why Choose Us,” Broward Factor Service. [Online] Available: [Accessed: Feb. 22, 2010]. [2] “You Can Save 80% per month on Your Electric Bill,” Energy Trio. [Online] Available: [Accessed: Feb. 22, 2010]. [3] “Air Handlers,” Amana. [Online] Available: [Accessed: Feb. 22, 2010]. [4] “Danger High Voltage,” Speedysigns. [Online] Available: Feb. 22, 2010]. [5] “Sign High Voltage clip art,” Clker.com. [Online] Available: [Accessed: Feb. 22, 2010]. [6] “1591XXCGY”, Mouser.com. [Online] Available: [Accessed: Oct. 2, 2010].

Questions?