Power Budget Automation System Team #40 Hai Vo, Ho Chuen Tsang, Vi Tran ECE 445 Senior Design April 30 st, 2013

Outline Introduction Objective Design Overview Requirement and Verification Functional tests Successes & Challenges Future Work Questions

Introduction Low cost home automatic and remote system Energy optimization

Features Access control Monitor power & energy usage Switching power based on occupation & energy limit Energy Priority Setting*

Design overview Hub (controller) Sensors

Design overview START Transmit command Input Receive command Processing Relay Energy usage Transmit data Receive data Display Detection memory NO YES Processing

Design overview Hub(controller) unit Micro-controller Transceiver Battery User I/O

Design overview Hub(controller) unit Power Supply (battery) Micro- Controller Transceiver User I/O (LCD)

Design overview Sensor unit Motion sensor PIR Transceiver Microcontroller Power Measurement Relay Power supply AC/DC converter

Design overview Sensor unit Transceiver Micro- Controller Relay PIR AC/DC converter Power Supply Power measurement

Requirement & Verification Verification 1. - observe frequency and duty cycle 2. - Use spectrum analyze, software (data), configuration 3. - Confirm using voltmeter and oscilloscope. Requirement 1. Microcontroller - Processing function 2. Transceiver - Transmit/receive data - Implementation 3. Power Supply -±15V, 5V, 3.3V - ripple under 1%

Requirement & Verification Verification 4. - Observe output signal at different placement Confirm LCD response after pressing button 6. - Use oscilloscope to check waveform Requirement 4. PIR Sensor - sense human motion 5. User Input/Output - Display correct function 6. Power Measurement - ripple less than 20mV p-p - Power detection range 0W- 200W

Microcontroller TI MSP430G2553 (Launchpad) Serial interface, 250uA at active operation 10bit ADC, 14 I/O ports Requirement Voltage required 3.3V Speed 16Mhz

Wire connection Internal clock is 1kHz Communication speed 0.2s Use 2 wires connection

Power Supply AC/DC Converter

Power Supply (Rectifier) Waveform after rectifier

Power Supply

Power Measurement

Power measurement

Shunt resistor: 0.15Ω Detect range: 0W-267W Voltage/Watt Ratio: ~15mV/W R shunt, V/W

Power measurement Slope: ~14mV/W Range: 0W-230W Linear slope up to 170W

Power measurement Slope: 15mV/W Range: 0W-176W Linear slope

Power measurement R load (Ω)P circuit (W)I load (A)V out (V)P measure (W) Max error: <±2%

Power measurement Without RC filter V out Ripple is ~49mV

Power measurement With filter C=100uF, Ripple is ~49mV

Power measurement With filter C=1mF, Ripple is ~8.4mV

Communication RF Anaren A11LR09x – CC110L transceiver Protocol series, frequency 906Mhz – 915Mhz Low data rates and lower power consumption

Communication Requirement Voltage required 3.3V Communicate between units less than 2s in 915Mhz Correctly sent and receive data bit value 1% error Distance of communication Is 20 meters indoor Implementation with circuit design

Communication Frequency signal Current measurement

Communication Signal Strength Process Voltage required 3.3V Communicate between units less than 2s in 915Mhz Correctly sent and receive data bit value 1% error Distance of communication Is 20 meters indoor Implementation with circuit design

Occupancy detection PIR sensor -20mA active -detect 15ft away Requirement correct output high/low signal with 3-5V power supply 1k PIR 2N2222 3V

Occupancy detection Verification Different displacement Oscilloscope: waveform

Software Function Menu 1.Automation On/Off 2.Manually Control Power 3.Display Power & Energy Usage 4.Setting Energy limit 5.Look back Energy Usage history

User I/O

Duty cycle of input button

User I/O Screen display system function

Energy Priority Concept Combination of occupation, enery limit and memory Store and extract information Different setting Challenge: software

Successes Basic Functionality (power measurement, detection, energy usage history etc.) High accuracy power measurement Reliable control Well designed PCB

Challenges Hardware Limit (Suggestion: ARM-CORTEX) Energy Priority Budget

Solution and Future work Time management (hardware) - Develop more robust wireless communications Software Memory implementation

Thanks Prof. Paul Scott Carney Igor Fedorov (Teaching Assistant) Kevin James Colravy (Power lab) Mark Smart and Waltham Smith (ECE part shop)

Questions