LightSaVers Satya Bhan Andrew Ausley Michael Moseley 1

Project Overview Schematic Modules Lighting Stepper & Sensors Design Decisions & Tradeoffs Testing & Demo 2

 Automated light balancing via remote blinds and dimmers  Centralized, low-power wireless network  Low bandwidth information feed via remote sensor network  LED-based light fixture 3

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 Low-power, LED based lighting to reduce energy costs  Brightness comparable to 100W light bulb  Automated dimming using a microcontroller  AC-to-DC power supply removes the need for batteries  Medium Edison adapter allows the wireless LED light to connect to standard light socket 5

6  Power Line Interface: Pig Nose adapter  Power Supply:120VAC-12VDC transformer  12VDC stepdown: Resistors and zener diodes  Power LEDs: 9 Luxeon Rebel I (lambertian)  LED topography: 3 branches of 3 diodes each

 The Pig Nose adapter provides superior interchangeability  The transformer is an easy implementation but not efficient and is expensive and bulky  The diode based stepdown circuit is quick and easy but it draws a set amount of current continuously reducing efficiency  The LEDs are a matter of preference  The topography depends on the DC voltage, desired light output, desired robustness 7

 Remote stepper motor for blinds modulation  Interfaced with microcontroller via 4 MOSFETs  Connected to window light sensor  5VDC transformer power supply 8

 Operates at 800mA  Requires 5VDC  Steps based on applied voltages to control transistors 9

 Stepper motor: Power/torque  Transistors: Voltage/current rating  Power supply: transformer vs. transformerless  ZigBee: One vs. Two modules 10

11  Rapidity of the design process led to budget overages  Necessity of reliable, easily implemented power step-down led to loss of efficiency  Time constraints and part availability led to implementation of expensive microcontrollers

 The drivers, the power supply, and the stepdown circuits should be implemented in a single compact semiconductor chip  A simple stepper motor mount should be designed  The system should be designed on the minimum possible microcontroller  A custom heat sink should be designed 12

13  Cover sensors and simulate the flowchart  System will not be run for a long period of time due to robustness issues  Blinds may be operated manually pending mechanical mounting of the stepper  The power savings will be tested by measuring the current flowing to the light fixture vs. that of an incandescent light bulb

14  The system will be implemented in the Aware Home on 10 th St.  The flowchart simulation will be demonstrated as well as the measurement techniques for measuring the current